<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:intro" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">The carbon cycle and geochemistry of radiatively active trace gases</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@html+block@The_carbon_cycle_and_geochemistry_of_radiatively_active_trace_gases"> <div class="xblock xblock-public_view xblock-public_view-html xmodule_display xmodule_HtmlBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@html+block@The_carbon_cycle_and_geochemistry_of_radiatively_active_trace_gases" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="html" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "HTMLModule"} </script> <h2>The carbon cycle and geochemistry of radiatively active trace gases</h2> <p>To this point in the course, a lot of discussion on the greenhouse effect has centered around carbon dioxide. In this module, we will introduce the <b>carbon cycle</b>. This biogeochemical cycle accounts for the sources and sinks of atmospheric CO₂, as well as carbon in other parts of the Earth system, on short-term to geologic time scales. As such, the carbon cycle plays a very important role in modulating the Earth's climate.</p> <p>On the other hand, carbon dioxide is not the only gas in the Earth's atmosphere that plays an important role in climate. As we have seen earlier in the course, there are several trace gases that contribute to the greenhouse effect by interacting with radiation in the atmosphere. In this module, we will delve a bit deeper into the geochemistry of these gases, and study their sources, sinks and lifetimes.</p> <p><i>Instructors: David McGee, Dan Cziczo</i></p> <h2>Module outline</h2> <p>This module is broadly in two parts. First, we will study the carbon cycle, and discuss the ways in which carbon levels are determined in various components of the Earth system. Then, we will focus on the greenhouse gases other than CO₂, specifically on their climatology, geochemistry, and global warming potentials.</p> <ul> <li>Introduction to the carbon cycle</li> <li>On overview of sources, sinks, and reservoirs for atmospheric CO₂</li> <li>The physics and chemistry governing carbon in the ocean</li> <li>The carbon cycle on geologic time scales, including the importances of <i>weathering</i>, <i>volcanism</i>, and <i>burial</i></li> <li>An overview of the current state of greenhouse gases other than CO₂</li> <li>The concept of <b>global warming potential</b> applied to various atmospheric trace gases</li> <li>The importance of chlorofluorocarbons in the depletion of the ozone layer, and their history including the Montreal protocol</li> </ul> <h2>Background reading</h2> <p>Some material in this module will rely somewhat on the concept of chemical equilibrium. For some background on that subject, see <a href="http://ocw.mit.edu/courses/chemistry/5-111-principles-of-chemical-science-fall-2008/readings-and-lecture-notes/lecnotes19.pdf" target="_blank">these lecture notes</a> from <a href="http://ocw.mit.edu/courses/chemistry/5-111-principles-of-chemical-science-fall-2008/readings-and-lecture-notes/" target="_blank">MIT OCW 5.111</a>.</p> <h2>Supplemental reading</h2> <p>This module will provide a broad overview of the carbon cycle and the roles of radiatively active trace gases in the climate system. To learn more about carbon and other biogeochemical cycles, see <a href="http://www.climatechange2013.org/images/report/WG1AR5_Chapter06_FINAL.pdf" target="_blank">Chapter 6</a> of the <a href="http://www.ipcc.ch/report/ar5/wg1/" target="_blank">IPCC AR5 report</a>. Furthermore, a slightly less-technical discussion of the carbon cycle can be found at <a href="http://earthobservatory.nasa.gov/Features/CarbonCycle/?src=eoa-features" target="_blank">NASA Earth Observatory</a>.</p> </div> </div> </div> </div>

<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:vclip1" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Introduction to the Carbon Cycle</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@video+block@Introduction_to_the_Carbon_Cycle"> <div class="xblock xblock-public_view xblock-public_view-video xmodule_display xmodule_VideoBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@video+block@Introduction_to_the_Carbon_Cycle" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="video" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Video"} </script> <h3 class="hd hd-2">Introduction to the Carbon Cycle</h3> <div id="video_Introduction_to_the_Carbon_Cycle" class="video closed" data-metadata='{&#34;savedVideoPosition&#34;: 0.0, &#34;recordedYoutubeIsAvailable&#34;: true, &#34;lmsRootURL&#34;: &#34;https://openlearninglibrary.mit.edu&#34;, &#34;saveStateEnabled&#34;: false, &#34;speed&#34;: null, &#34;start&#34;: 0.0, &#34;transcriptAvailableTranslationsUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Introduction_to_the_Carbon_Cycle/handler/transcript/available_translations&#34;, &#34;autohideHtml5&#34;: false, &#34;publishCompletionUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Introduction_to_the_Carbon_Cycle/handler/publish_completion&#34;, &#34;completionPercentage&#34;: 0.95, &#34;generalSpeed&#34;: 1.0, &#34;completionEnabled&#34;: false, &#34;prioritizeHls&#34;: false, &#34;transcriptTranslationUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Introduction_to_the_Carbon_Cycle/handler/transcript/translation/__lang__&#34;, &#34;captionDataDir&#34;: null, &#34;sources&#34;: [], &#34;poster&#34;: null, &#34;ytMetadataEndpoint&#34;: &#34;&#34;, &#34;showCaptions&#34;: &#34;false&#34;, &#34;end&#34;: 0.0, &#34;saveStateUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Introduction_to_the_Carbon_Cycle/handler/xmodule_handler/save_user_state&#34;, &#34;autoplay&#34;: false, &#34;transcriptLanguage&#34;: &#34;en&#34;, &#34;duration&#34;: null, &#34;transcriptLanguages&#34;: {&#34;en&#34;: &#34;English&#34;}, &#34;autoAdvance&#34;: false, &#34;ytApiUrl&#34;: &#34;https://www.youtube.com/iframe_api&#34;, &#34;ytTestTimeout&#34;: 1500, &#34;streams&#34;: &#34;1.00:KEeQ8SdfzbA&#34;}' data-bumper-metadata='null' data-autoadvance-enabled="False" data-poster='null' tabindex="-1" > <div class="focus_grabber first"></div> <div class="tc-wrapper"> <div class="video-wrapper"> <span tabindex="0" class="spinner" aria-hidden="false" aria-label="Loading video player"></span> <span tabindex="-1" class="btn-play fa fa-youtube-play fa-2x is-hidden" aria-hidden="true" aria-label="Play video"></span> <div class="video-player-pre"></div> <div class="video-player"> <div id="Introduction_to_the_Carbon_Cycle"></div> <h4 class="hd hd-4 video-error is-hidden">No playable video sources found.</h4> <h4 class="hd hd-4 video-hls-error is-hidden"> Your browser does not support this video format. 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We also know that the pre-industrial atmosphere had about 280 ppm of carbon dioxide. The conversion factor is thus approximately 2.11 gigatons of Carbon per ppm carbon dioxide. If none of the current anthropogenic emissions of carbon were taken up by the ocean or terrestrial biosphere, what would be the approximate rate of increase of atmospheric carbon dioxide concentration?&lt;/p&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div class=&#34;choicegroup capa_inputtype&#34; id=&#34;inputtype_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34;&gt; &lt;fieldset aria-describedby=&#34;status_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34;&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34; id=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_0&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_0&#34;/&gt;&lt;label id=&#34;Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1-choice_0-label&#34; for=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_0&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34;&gt; &lt;text&gt;0.96 ppm/year&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34; id=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_1&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_1&#34;/&gt;&lt;label id=&#34;Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1-choice_1-label&#34; for=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_1&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34;&gt; &lt;text&gt;9.6 ppm/year&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34; id=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_2&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_2&#34;/&gt;&lt;label id=&#34;Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1-choice_2-label&#34; for=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_2&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34;&gt; &lt;text&gt;20.3 ppm/year&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34; id=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_3&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_3&#34;/&gt;&lt;label id=&#34;Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1-choice_3-label&#34; for=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_3&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34;&gt; &lt;text&gt;2.1 ppm/year&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34; id=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_4&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_4&#34;/&gt;&lt;label id=&#34;Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1-choice_4-label&#34; for=&#34;input_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1_choice_4&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34;&gt; &lt;text&gt;4.7 ppm/year&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;span id=&#34;answer_Gt_to_ppm_conversion_and_the_long-term_CO2_trend_2_1&#34;/&gt; &lt;/fieldset&gt; &lt;div class=&#34;indicator-container&#34;&gt; &lt;span class=&#34;status unanswered&#34; 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<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:vclip2" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Carbon in the Ocean</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@video+block@Carbon_in_the_Ocean"> <div class="xblock xblock-public_view xblock-public_view-video xmodule_display xmodule_VideoBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@video+block@Carbon_in_the_Ocean" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="video" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Video"} </script> <h3 class="hd hd-2">Carbon in the Ocean</h3> <div id="video_Carbon_in_the_Ocean" class="video closed" data-metadata='{&#34;savedVideoPosition&#34;: 0.0, &#34;recordedYoutubeIsAvailable&#34;: true, &#34;lmsRootURL&#34;: &#34;https://openlearninglibrary.mit.edu&#34;, &#34;saveStateEnabled&#34;: false, &#34;speed&#34;: null, &#34;start&#34;: 0.0, &#34;transcriptAvailableTranslationsUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Carbon_in_the_Ocean/handler/transcript/available_translations&#34;, &#34;autohideHtml5&#34;: false, &#34;publishCompletionUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Carbon_in_the_Ocean/handler/publish_completion&#34;, &#34;completionPercentage&#34;: 0.95, &#34;generalSpeed&#34;: 1.0, &#34;completionEnabled&#34;: false, &#34;prioritizeHls&#34;: false, &#34;transcriptTranslationUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Carbon_in_the_Ocean/handler/transcript/translation/__lang__&#34;, &#34;captionDataDir&#34;: null, &#34;sources&#34;: [], &#34;poster&#34;: null, &#34;ytMetadataEndpoint&#34;: &#34;&#34;, &#34;showCaptions&#34;: &#34;false&#34;, &#34;end&#34;: 0.0, &#34;saveStateUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Carbon_in_the_Ocean/handler/xmodule_handler/save_user_state&#34;, &#34;autoplay&#34;: false, &#34;transcriptLanguage&#34;: &#34;en&#34;, &#34;duration&#34;: null, &#34;transcriptLanguages&#34;: {&#34;en&#34;: &#34;English&#34;}, &#34;autoAdvance&#34;: false, &#34;ytApiUrl&#34;: &#34;https://www.youtube.com/iframe_api&#34;, &#34;ytTestTimeout&#34;: 1500, &#34;streams&#34;: &#34;1.00:-RFNwmsJ96M&#34;}' data-bumper-metadata='null' data-autoadvance-enabled="False" data-poster='null' tabindex="-1" > <div class="focus_grabber first"></div> <div class="tc-wrapper"> <div class="video-wrapper"> <span tabindex="0" class="spinner" aria-hidden="false" aria-label="Loading video player"></span> <span tabindex="-1" class="btn-play fa fa-youtube-play fa-2x is-hidden" aria-hidden="true" aria-label="Play video"></span> <div class="video-player-pre"></div> <div class="video-player"> <div id="Carbon_in_the_Ocean"></div> <h4 class="hd hd-4 video-error is-hidden">No playable video sources found.</h4> <h4 class="hd hd-4 video-hls-error is-hidden"> Your browser does not support this video format. 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The partitioning of carbon dioxide between the atmosphere and ocean will be explored in more detail in the problem set. Suppose a large asteroid made of calcium hydroxide, a strong base, hit the earth and increased the pH of the global oceans to 10 (suspend your disbelief, for the moment, about the size and unusual chemical composition required of such an object). Assuming that global temperatures do not change, in what form would most of the dissolved inorganic carbon in this much more basic ocean reside, and would the amount of dissolved inorganic carbon in the ocean increase or decrease?&lt;/p&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div class=&#34;choicegroup capa_inputtype&#34; id=&#34;inputtype_A_calcium_hydroxide_asteroid_2_1&#34;&gt; &lt;fieldset aria-describedby=&#34;status_A_calcium_hydroxide_asteroid_2_1&#34;&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_A_calcium_hydroxide_asteroid_2_1&#34; id=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_0&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_0&#34;/&gt;&lt;label id=&#34;A_calcium_hydroxide_asteroid_2_1-choice_0-label&#34; for=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_0&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_A_calcium_hydroxide_asteroid_2_1&#34;&gt; &lt;text&gt;CO[mathjaxinline]_2^*[/mathjaxinline], decrease&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_A_calcium_hydroxide_asteroid_2_1&#34; id=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_1&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_1&#34;/&gt;&lt;label id=&#34;A_calcium_hydroxide_asteroid_2_1-choice_1-label&#34; for=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_1&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_A_calcium_hydroxide_asteroid_2_1&#34;&gt; &lt;text&gt;HCO[mathjaxinline]_3^-[/mathjaxinline], decrease&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_A_calcium_hydroxide_asteroid_2_1&#34; id=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_2&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_2&#34;/&gt;&lt;label id=&#34;A_calcium_hydroxide_asteroid_2_1-choice_2-label&#34; for=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_2&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_A_calcium_hydroxide_asteroid_2_1&#34;&gt; &lt;text&gt;CO[mathjaxinline]_3^{2-}[/mathjaxinline], decrease&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_A_calcium_hydroxide_asteroid_2_1&#34; id=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_3&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_3&#34;/&gt;&lt;label id=&#34;A_calcium_hydroxide_asteroid_2_1-choice_3-label&#34; for=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_3&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_A_calcium_hydroxide_asteroid_2_1&#34;&gt; &lt;text&gt;CO[mathjaxinline]_2^*[/mathjaxinline], increase&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_A_calcium_hydroxide_asteroid_2_1&#34; id=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_4&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_4&#34;/&gt;&lt;label id=&#34;A_calcium_hydroxide_asteroid_2_1-choice_4-label&#34; for=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_4&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_A_calcium_hydroxide_asteroid_2_1&#34;&gt; &lt;text&gt;HCO[mathjaxinline]_3^-[/mathjaxinline], increase&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_A_calcium_hydroxide_asteroid_2_1&#34; id=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_5&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_5&#34;/&gt;&lt;label id=&#34;A_calcium_hydroxide_asteroid_2_1-choice_5-label&#34; for=&#34;input_A_calcium_hydroxide_asteroid_2_1_choice_5&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_A_calcium_hydroxide_asteroid_2_1&#34;&gt; &lt;text&gt;CO[mathjaxinline]_3^{2-}[/mathjaxinline], increase&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;span id=&#34;answer_A_calcium_hydroxide_asteroid_2_1&#34;/&gt; &lt;/fieldset&gt; &lt;div class=&#34;indicator-container&#34;&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_A_calcium_hydroxide_asteroid_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_A_calcium_hydroxide_asteroid_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;A calcium hydroxide asteroid&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_A_calcium_hydroxide_asteroid&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_A_calcium_hydroxide_asteroid&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. 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<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:vclip3" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Ocean Carbon Pumps</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@video+block@Ocean_Carbon_Pumps"> <div class="xblock xblock-public_view xblock-public_view-video xmodule_display xmodule_VideoBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@video+block@Ocean_Carbon_Pumps" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="video" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Video"} </script> <h3 class="hd hd-2">Ocean Carbon Pumps</h3> <div id="video_Ocean_Carbon_Pumps" class="video closed" data-metadata='{&#34;savedVideoPosition&#34;: 0.0, &#34;recordedYoutubeIsAvailable&#34;: true, &#34;lmsRootURL&#34;: &#34;https://openlearninglibrary.mit.edu&#34;, &#34;saveStateEnabled&#34;: false, &#34;speed&#34;: null, &#34;start&#34;: 0.0, &#34;transcriptAvailableTranslationsUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Ocean_Carbon_Pumps/handler/transcript/available_translations&#34;, &#34;autohideHtml5&#34;: false, &#34;publishCompletionUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Ocean_Carbon_Pumps/handler/publish_completion&#34;, &#34;completionPercentage&#34;: 0.95, &#34;generalSpeed&#34;: 1.0, &#34;completionEnabled&#34;: false, &#34;prioritizeHls&#34;: false, &#34;transcriptTranslationUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Ocean_Carbon_Pumps/handler/transcript/translation/__lang__&#34;, &#34;captionDataDir&#34;: null, &#34;sources&#34;: [], &#34;poster&#34;: null, &#34;ytMetadataEndpoint&#34;: &#34;&#34;, &#34;showCaptions&#34;: &#34;false&#34;, &#34;end&#34;: 0.0, &#34;saveStateUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Ocean_Carbon_Pumps/handler/xmodule_handler/save_user_state&#34;, &#34;autoplay&#34;: false, &#34;transcriptLanguage&#34;: &#34;en&#34;, &#34;duration&#34;: null, &#34;transcriptLanguages&#34;: {&#34;en&#34;: &#34;English&#34;}, &#34;autoAdvance&#34;: false, &#34;ytApiUrl&#34;: &#34;https://www.youtube.com/iframe_api&#34;, &#34;ytTestTimeout&#34;: 1500, &#34;streams&#34;: &#34;1.00:w5Ck3f20pXc&#34;}' data-bumper-metadata='null' data-autoadvance-enabled="False" data-poster='null' tabindex="-1" > <div class="focus_grabber first"></div> <div class="tc-wrapper"> <div class="video-wrapper"> <span tabindex="0" class="spinner" aria-hidden="false" aria-label="Loading video player"></span> <span tabindex="-1" class="btn-play fa fa-youtube-play fa-2x is-hidden" aria-hidden="true" aria-label="Play video"></span> <div class="video-player-pre"></div> <div class="video-player"> <div id="Ocean_Carbon_Pumps"></div> <h4 class="hd hd-4 video-error is-hidden">No playable video sources found.</h4> <h4 class="hd hd-4 video-hls-error is-hidden"> Your browser does not support this video format. 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id=&#34;Gradients_in_Dissolved_Inorganic_Carbon-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@Gradients_in_Dissolved_Inorganic_Carbon-problem-progress&#34; tabindex=&#34;-1&#34;&gt; Gradients in Dissolved Inorganic Carbon &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@Gradients_in_Dissolved_Inorganic_Carbon-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;p&gt;Which of the following is the best explanation for why the ocean has gradients in dissolved inorganic carbon concentration?&lt;/p&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div class=&#34;choicegroup capa_inputtype&#34; id=&#34;inputtype_Gradients_in_Dissolved_Inorganic_Carbon_2_1&#34;&gt; &lt;fieldset aria-describedby=&#34;status_Gradients_in_Dissolved_Inorganic_Carbon_2_1&#34;&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Gradients_in_Dissolved_Inorganic_Carbon_2_1&#34; id=&#34;input_Gradients_in_Dissolved_Inorganic_Carbon_2_1_choice_0&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_0&#34;/&gt;&lt;label id=&#34;Gradients_in_Dissolved_Inorganic_Carbon_2_1-choice_0-label&#34; for=&#34;input_Gradients_in_Dissolved_Inorganic_Carbon_2_1_choice_0&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Gradients_in_Dissolved_Inorganic_Carbon_2_1&#34;&gt; &lt;text&gt;Volcanism at mid-ocean ridges injects carbon dioxide at depth, increasing the concentrations in the deep ocean&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Gradients_in_Dissolved_Inorganic_Carbon_2_1&#34; id=&#34;input_Gradients_in_Dissolved_Inorganic_Carbon_2_1_choice_1&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_1&#34;/&gt;&lt;label id=&#34;Gradients_in_Dissolved_Inorganic_Carbon_2_1-choice_1-label&#34; for=&#34;input_Gradients_in_Dissolved_Inorganic_Carbon_2_1_choice_1&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Gradients_in_Dissolved_Inorganic_Carbon_2_1&#34;&gt; &lt;text&gt;Anthropogenic carbon dioxide emissions, especially in mid-latitudes, have come to equilibrium with near-surface waters, but not with the deep ocean&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Gradients_in_Dissolved_Inorganic_Carbon_2_1&#34; id=&#34;input_Gradients_in_Dissolved_Inorganic_Carbon_2_1_choice_2&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_2&#34;/&gt;&lt;label id=&#34;Gradients_in_Dissolved_Inorganic_Carbon_2_1-choice_2-label&#34; for=&#34;input_Gradients_in_Dissolved_Inorganic_Carbon_2_1_choice_2&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Gradients_in_Dissolved_Inorganic_Carbon_2_1&#34;&gt; &lt;text&gt;Increased solubility of carbon dioxide at lower water temperatures combines with ocean circulation to determine patterns of dissolved inorganic carbon concentration &lt;/text&gt; 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<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:vclip4" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Long-Term Carbon Cycling</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@video+block@Long-term_Carbon_Cycling"> <div class="xblock xblock-public_view xblock-public_view-video xmodule_display xmodule_VideoBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@video+block@Long-term_Carbon_Cycling" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="video" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Video"} </script> <h3 class="hd hd-2">Long-term Carbon Cycling</h3> <div id="video_Long-term_Carbon_Cycling" class="video closed" data-metadata='{&#34;savedVideoPosition&#34;: 0.0, &#34;recordedYoutubeIsAvailable&#34;: true, &#34;lmsRootURL&#34;: &#34;https://openlearninglibrary.mit.edu&#34;, &#34;saveStateEnabled&#34;: false, &#34;speed&#34;: null, &#34;start&#34;: 0.0, &#34;transcriptAvailableTranslationsUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Long-term_Carbon_Cycling/handler/transcript/available_translations&#34;, &#34;autohideHtml5&#34;: false, &#34;publishCompletionUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Long-term_Carbon_Cycling/handler/publish_completion&#34;, &#34;completionPercentage&#34;: 0.95, &#34;generalSpeed&#34;: 1.0, &#34;completionEnabled&#34;: false, &#34;prioritizeHls&#34;: false, &#34;transcriptTranslationUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Long-term_Carbon_Cycling/handler/transcript/translation/__lang__&#34;, &#34;captionDataDir&#34;: null, &#34;sources&#34;: [], &#34;poster&#34;: null, &#34;ytMetadataEndpoint&#34;: &#34;&#34;, &#34;showCaptions&#34;: &#34;false&#34;, &#34;end&#34;: 0.0, &#34;saveStateUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Long-term_Carbon_Cycling/handler/xmodule_handler/save_user_state&#34;, &#34;autoplay&#34;: false, &#34;transcriptLanguage&#34;: &#34;en&#34;, &#34;duration&#34;: null, &#34;transcriptLanguages&#34;: {&#34;en&#34;: &#34;English&#34;}, &#34;autoAdvance&#34;: false, &#34;ytApiUrl&#34;: &#34;https://www.youtube.com/iframe_api&#34;, &#34;ytTestTimeout&#34;: 1500, &#34;streams&#34;: &#34;1.00:9n3XrtMNSSc&#34;}' data-bumper-metadata='null' data-autoadvance-enabled="False" data-poster='null' tabindex="-1" > <div class="focus_grabber first"></div> <div class="tc-wrapper"> <div class="video-wrapper"> <span tabindex="0" class="spinner" aria-hidden="false" aria-label="Loading video player"></span> <span tabindex="-1" class="btn-play fa fa-youtube-play fa-2x is-hidden" aria-hidden="true" aria-label="Play video"></span> <div class="video-player-pre"></div> <div class="video-player"> <div id="Long-term_Carbon_Cycling"></div> <h4 class="hd hd-4 video-error is-hidden">No playable video sources found.</h4> <h4 class="hd hd-4 video-hls-error is-hidden"> Your browser does not support this video format. 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Consider the ocean/atmosphere system to have 40,000 Pg of Carbon, and the rate of weathering, which balances volcanism, to be about 0.4 Pg C/year. If weathering suddenly increased by 10%, and continued at this level regardless of the amount of carbon in the atmosphere/ocean system, how long would it take to completely draw down the atmospheric and oceanic carbon to 0?&lt;/p&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div class=&#34;choicegroup capa_inputtype&#34; id=&#34;inputtype_Long-term_weathering-volcanism_imbalance_2_1&#34;&gt; &lt;fieldset aria-describedby=&#34;status_Long-term_weathering-volcanism_imbalance_2_1&#34;&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Long-term_weathering-volcanism_imbalance_2_1&#34; id=&#34;input_Long-term_weathering-volcanism_imbalance_2_1_choice_0&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_0&#34;/&gt;&lt;label id=&#34;Long-term_weathering-volcanism_imbalance_2_1-choice_0-label&#34; for=&#34;input_Long-term_weathering-volcanism_imbalance_2_1_choice_0&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Long-term_weathering-volcanism_imbalance_2_1&#34;&gt; &lt;text&gt;100,000 years&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Long-term_weathering-volcanism_imbalance_2_1&#34; id=&#34;input_Long-term_weathering-volcanism_imbalance_2_1_choice_1&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_1&#34;/&gt;&lt;label id=&#34;Long-term_weathering-volcanism_imbalance_2_1-choice_1-label&#34; for=&#34;input_Long-term_weathering-volcanism_imbalance_2_1_choice_1&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Long-term_weathering-volcanism_imbalance_2_1&#34;&gt; &lt;text&gt;1,000,000 years&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Long-term_weathering-volcanism_imbalance_2_1&#34; id=&#34;input_Long-term_weathering-volcanism_imbalance_2_1_choice_2&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_2&#34;/&gt;&lt;label id=&#34;Long-term_weathering-volcanism_imbalance_2_1-choice_2-label&#34; for=&#34;input_Long-term_weathering-volcanism_imbalance_2_1_choice_2&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Long-term_weathering-volcanism_imbalance_2_1&#34;&gt; &lt;text&gt;100,000,000 years&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Long-term_weathering-volcanism_imbalance_2_1&#34; id=&#34;input_Long-term_weathering-volcanism_imbalance_2_1_choice_3&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_3&#34;/&gt;&lt;label id=&#34;Long-term_weathering-volcanism_imbalance_2_1-choice_3-label&#34; for=&#34;input_Long-term_weathering-volcanism_imbalance_2_1_choice_3&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Long-term_weathering-volcanism_imbalance_2_1&#34;&gt; &lt;text&gt;1,000,000,000 years&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;span id=&#34;answer_Long-term_weathering-volcanism_imbalance_2_1&#34;/&gt; &lt;/fieldset&gt; &lt;div class=&#34;indicator-container&#34;&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_Long-term_weathering-volcanism_imbalance_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_Long-term_weathering-volcanism_imbalance_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;Long-term weathering-volcanism imbalance&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_Long-term_weathering-volcanism_imbalance&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_Long-term_weathering-volcanism_imbalance&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. 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<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:vclip5" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Trends and Sources of Non-CO2 GHGs</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@video+block@Trends_and_Sources_of_Non-CO2_GHGs"> <div class="xblock xblock-public_view xblock-public_view-video xmodule_display xmodule_VideoBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@video+block@Trends_and_Sources_of_Non-CO2_GHGs" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="video" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Video"} </script> <h3 class="hd hd-2">Trends and Sources of Non-CO2 GHGs</h3> <div id="video_Trends_and_Sources_of_Non-CO2_GHGs" class="video closed" data-metadata='{&#34;savedVideoPosition&#34;: 0.0, &#34;recordedYoutubeIsAvailable&#34;: true, &#34;lmsRootURL&#34;: &#34;https://openlearninglibrary.mit.edu&#34;, &#34;saveStateEnabled&#34;: false, &#34;speed&#34;: null, &#34;start&#34;: 0.0, &#34;transcriptAvailableTranslationsUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Trends_and_Sources_of_Non-CO2_GHGs/handler/transcript/available_translations&#34;, &#34;autohideHtml5&#34;: false, &#34;publishCompletionUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Trends_and_Sources_of_Non-CO2_GHGs/handler/publish_completion&#34;, &#34;completionPercentage&#34;: 0.95, &#34;generalSpeed&#34;: 1.0, &#34;completionEnabled&#34;: false, &#34;prioritizeHls&#34;: false, &#34;transcriptTranslationUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Trends_and_Sources_of_Non-CO2_GHGs/handler/transcript/translation/__lang__&#34;, &#34;captionDataDir&#34;: null, &#34;sources&#34;: [], &#34;poster&#34;: null, &#34;ytMetadataEndpoint&#34;: &#34;&#34;, &#34;showCaptions&#34;: &#34;false&#34;, &#34;end&#34;: 0.0, &#34;saveStateUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Trends_and_Sources_of_Non-CO2_GHGs/handler/xmodule_handler/save_user_state&#34;, &#34;autoplay&#34;: false, &#34;transcriptLanguage&#34;: &#34;en&#34;, &#34;duration&#34;: null, &#34;transcriptLanguages&#34;: {&#34;en&#34;: &#34;English&#34;}, &#34;autoAdvance&#34;: false, &#34;ytApiUrl&#34;: &#34;https://www.youtube.com/iframe_api&#34;, &#34;ytTestTimeout&#34;: 1500, &#34;streams&#34;: &#34;1.00:6AIXzMhGpi4&#34;}' data-bumper-metadata='null' data-autoadvance-enabled="False" data-poster='null' tabindex="-1" > <div class="focus_grabber first"></div> <div class="tc-wrapper"> <div class="video-wrapper"> <span tabindex="0" class="spinner" aria-hidden="false" aria-label="Loading video player"></span> <span tabindex="-1" class="btn-play fa fa-youtube-play fa-2x is-hidden" aria-hidden="true" aria-label="Play video"></span> <div class="video-player-pre"></div> <div class="video-player"> <div id="Trends_and_Sources_of_Non-CO2_GHGs"></div> <h4 class="hd hd-4 video-error is-hidden">No playable video sources found.</h4> <h4 class="hd hd-4 video-hls-error is-hidden"> Your browser does not support this video format. 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id=&#34;Methane_and_Nitrous_Oxide_Sources-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@Methane_and_Nitrous_Oxide_Sources-problem-progress&#34; tabindex=&#34;-1&#34;&gt; Methane and Nitrous Oxide Sources &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@Methane_and_Nitrous_Oxide_Sources-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;p&gt;What economic sector contributes most to the emission of methane and nitrous oxide?&lt;/p&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div class=&#34;choicegroup capa_inputtype&#34; id=&#34;inputtype_Methane_and_Nitrous_Oxide_Sources_2_1&#34;&gt; &lt;fieldset aria-describedby=&#34;status_Methane_and_Nitrous_Oxide_Sources_2_1&#34;&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1&#34; id=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_0&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_0&#34;/&gt;&lt;label id=&#34;Methane_and_Nitrous_Oxide_Sources_2_1-choice_0-label&#34; for=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_0&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Methane_and_Nitrous_Oxide_Sources_2_1&#34;&gt; &lt;text&gt;Industry&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1&#34; id=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_1&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_1&#34;/&gt;&lt;label id=&#34;Methane_and_Nitrous_Oxide_Sources_2_1-choice_1-label&#34; for=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_1&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Methane_and_Nitrous_Oxide_Sources_2_1&#34;&gt; &lt;text&gt;Electricity Generation&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1&#34; id=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_2&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_2&#34;/&gt;&lt;label id=&#34;Methane_and_Nitrous_Oxide_Sources_2_1-choice_2-label&#34; for=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_2&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Methane_and_Nitrous_Oxide_Sources_2_1&#34;&gt; &lt;text&gt;Transportation&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1&#34; id=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_3&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_3&#34;/&gt;&lt;label id=&#34;Methane_and_Nitrous_Oxide_Sources_2_1-choice_3-label&#34; for=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_3&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Methane_and_Nitrous_Oxide_Sources_2_1&#34;&gt; &lt;text&gt;Residential and Commercial Sources&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1&#34; id=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_4&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_4&#34;/&gt;&lt;label id=&#34;Methane_and_Nitrous_Oxide_Sources_2_1-choice_4-label&#34; for=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_4&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Methane_and_Nitrous_Oxide_Sources_2_1&#34;&gt; &lt;text&gt;Fossil Fuel Extraction&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1&#34; id=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_5&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_5&#34;/&gt;&lt;label id=&#34;Methane_and_Nitrous_Oxide_Sources_2_1-choice_5-label&#34; for=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_5&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Methane_and_Nitrous_Oxide_Sources_2_1&#34;&gt; &lt;text&gt;Agriculture&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1&#34; id=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_6&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_6&#34;/&gt;&lt;label id=&#34;Methane_and_Nitrous_Oxide_Sources_2_1-choice_6-label&#34; for=&#34;input_Methane_and_Nitrous_Oxide_Sources_2_1_choice_6&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Methane_and_Nitrous_Oxide_Sources_2_1&#34;&gt; &lt;text&gt;Waste Disposal&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;span id=&#34;answer_Methane_and_Nitrous_Oxide_Sources_2_1&#34;/&gt; &lt;/fieldset&gt; &lt;div class=&#34;indicator-container&#34;&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_Methane_and_Nitrous_Oxide_Sources_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_Methane_and_Nitrous_Oxide_Sources_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;Methane and Nitrous Oxide Sources&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; 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<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:vclip6" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Global Warming Potential</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@video+block@Global_Warming_Potential"> <div class="xblock xblock-public_view xblock-public_view-video xmodule_display xmodule_VideoBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@video+block@Global_Warming_Potential" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="video" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Video"} </script> <h3 class="hd hd-2">Global Warming Potential</h3> <div id="video_Global_Warming_Potential" class="video closed" data-metadata='{&#34;savedVideoPosition&#34;: 0.0, &#34;recordedYoutubeIsAvailable&#34;: true, &#34;lmsRootURL&#34;: &#34;https://openlearninglibrary.mit.edu&#34;, &#34;saveStateEnabled&#34;: false, &#34;speed&#34;: null, &#34;start&#34;: 0.0, &#34;transcriptAvailableTranslationsUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Global_Warming_Potential/handler/transcript/available_translations&#34;, &#34;autohideHtml5&#34;: false, &#34;publishCompletionUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Global_Warming_Potential/handler/publish_completion&#34;, &#34;completionPercentage&#34;: 0.95, &#34;generalSpeed&#34;: 1.0, &#34;completionEnabled&#34;: false, &#34;prioritizeHls&#34;: false, &#34;transcriptTranslationUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Global_Warming_Potential/handler/transcript/translation/__lang__&#34;, &#34;captionDataDir&#34;: null, &#34;sources&#34;: [], &#34;poster&#34;: null, &#34;ytMetadataEndpoint&#34;: &#34;&#34;, &#34;showCaptions&#34;: &#34;false&#34;, &#34;end&#34;: 0.0, &#34;saveStateUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Global_Warming_Potential/handler/xmodule_handler/save_user_state&#34;, &#34;autoplay&#34;: false, &#34;transcriptLanguage&#34;: &#34;en&#34;, &#34;duration&#34;: null, &#34;transcriptLanguages&#34;: {&#34;en&#34;: &#34;English&#34;}, &#34;autoAdvance&#34;: false, &#34;ytApiUrl&#34;: &#34;https://www.youtube.com/iframe_api&#34;, &#34;ytTestTimeout&#34;: 1500, &#34;streams&#34;: &#34;1.00:qZnB8kTS1RA&#34;}' data-bumper-metadata='null' data-autoadvance-enabled="False" data-poster='null' tabindex="-1" > <div class="focus_grabber first"></div> <div class="tc-wrapper"> <div class="video-wrapper"> <span tabindex="0" class="spinner" aria-hidden="false" aria-label="Loading video player"></span> <span tabindex="-1" class="btn-play fa fa-youtube-play fa-2x is-hidden" aria-hidden="true" aria-label="Play video"></span> <div class="video-player-pre"></div> <div class="video-player"> <div id="Global_Warming_Potential"></div> <h4 class="hd hd-4 video-error is-hidden">No playable video sources found.</h4> <h4 class="hd hd-4 video-hls-error is-hidden"> Your browser does not support this video format. 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Given that sulfur hexafluoride has a 20-year GWP of 17,500, and a 100-year GWP of 23,500, which of the following can you infer?&lt;/p&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div class=&#34;choicegroup capa_inputtype&#34; id=&#34;inputtype_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34;&gt; &lt;fieldset aria-describedby=&#34;status_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34;&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34; id=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1_choice_0&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_0&#34;/&gt;&lt;label id=&#34;Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1-choice_0-label&#34; for=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1_choice_0&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34;&gt; &lt;text&gt;Sulfur hexafluoride has a smaller instantaneous radiative forcing and a shorter lifetime than carbon dioxide&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34; id=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1_choice_1&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_1&#34;/&gt;&lt;label id=&#34;Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1-choice_1-label&#34; for=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1_choice_1&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34;&gt; &lt;text&gt;Sulfur hexafluoride has a larger instantaneous radiative forcing and a shorter lifetime than carbon dioxide&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34; id=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1_choice_2&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_2&#34;/&gt;&lt;label id=&#34;Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1-choice_2-label&#34; for=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1_choice_2&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34;&gt; &lt;text&gt;Sulfur hexafluoride has a smaller instantaneous radiative forcing and a longer lifetime than carbon dioxide&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34; id=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1_choice_3&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_3&#34;/&gt;&lt;label id=&#34;Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1-choice_3-label&#34; for=&#34;input_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1_choice_3&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34;&gt; &lt;text&gt;Sulfur hexafluoride has a larger instantaneous radiative forcing and a longer lifetime than carbon dioxide&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;span id=&#34;answer_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34;/&gt; &lt;/fieldset&gt; &lt;div class=&#34;indicator-container&#34;&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_Global_Warming_Potential_of_Sulfur_Hexafluoride_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; 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<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:vclip7" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Chlorofluorocarbons and Ozone Depletion</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@video+block@Chlorofluorocarbons_and_Ozone_Depletion"> <div class="xblock xblock-public_view xblock-public_view-video xmodule_display xmodule_VideoBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@video+block@Chlorofluorocarbons_and_Ozone_Depletion" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="video" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Video"} </script> <h3 class="hd hd-2">Chlorofluorocarbons and Ozone Depletion</h3> <div id="video_Chlorofluorocarbons_and_Ozone_Depletion" class="video closed" data-metadata='{&#34;savedVideoPosition&#34;: 0.0, &#34;recordedYoutubeIsAvailable&#34;: true, &#34;lmsRootURL&#34;: &#34;https://openlearninglibrary.mit.edu&#34;, &#34;saveStateEnabled&#34;: false, &#34;speed&#34;: null, &#34;start&#34;: 0.0, &#34;transcriptAvailableTranslationsUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Chlorofluorocarbons_and_Ozone_Depletion/handler/transcript/available_translations&#34;, &#34;autohideHtml5&#34;: false, &#34;publishCompletionUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Chlorofluorocarbons_and_Ozone_Depletion/handler/publish_completion&#34;, &#34;completionPercentage&#34;: 0.95, &#34;generalSpeed&#34;: 1.0, &#34;completionEnabled&#34;: false, &#34;prioritizeHls&#34;: false, &#34;transcriptTranslationUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Chlorofluorocarbons_and_Ozone_Depletion/handler/transcript/translation/__lang__&#34;, &#34;captionDataDir&#34;: null, &#34;sources&#34;: [], &#34;poster&#34;: null, &#34;ytMetadataEndpoint&#34;: &#34;&#34;, &#34;showCaptions&#34;: &#34;false&#34;, &#34;end&#34;: 0.0, &#34;saveStateUrl&#34;: &#34;/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@video+block@Chlorofluorocarbons_and_Ozone_Depletion/handler/xmodule_handler/save_user_state&#34;, &#34;autoplay&#34;: false, &#34;transcriptLanguage&#34;: &#34;en&#34;, &#34;duration&#34;: null, &#34;transcriptLanguages&#34;: {&#34;en&#34;: &#34;English&#34;}, &#34;autoAdvance&#34;: false, &#34;ytApiUrl&#34;: &#34;https://www.youtube.com/iframe_api&#34;, &#34;ytTestTimeout&#34;: 1500, &#34;streams&#34;: &#34;1.00:DmIH3k2JFVU&#34;}' data-bumper-metadata='null' data-autoadvance-enabled="False" data-poster='null' tabindex="-1" > <div class="focus_grabber first"></div> <div class="tc-wrapper"> <div class="video-wrapper"> <span tabindex="0" class="spinner" aria-hidden="false" aria-label="Loading video player"></span> <span tabindex="-1" class="btn-play fa fa-youtube-play fa-2x is-hidden" aria-hidden="true" aria-label="Play video"></span> <div class="video-player-pre"></div> <div class="video-player"> <div id="Chlorofluorocarbons_and_Ozone_Depletion"></div> <h4 class="hd hd-4 video-error is-hidden">No playable video sources found.</h4> <h4 class="hd hd-4 video-hls-error is-hidden"> Your browser does not support this video format. 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Given that CFCs are greenhouse gases that also destroy ozone, which of the following statements best describes the impact of CFCs on the temperature of the stratosphere?&lt;/p&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div class=&#34;choicegroup capa_inputtype&#34; id=&#34;inputtype_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34;&gt; &lt;fieldset aria-describedby=&#34;status_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34;&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34; id=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1_choice_0&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_0&#34;/&gt;&lt;label id=&#34;Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1-choice_0-label&#34; for=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1_choice_0&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34;&gt; &lt;text&gt;CFCs tend to warm the stratosphere as greenhouse gases, but cool it because of their role in destroying ozone and reducing solar absorption.&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34; id=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1_choice_1&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_1&#34;/&gt;&lt;label id=&#34;Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1-choice_1-label&#34; for=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1_choice_1&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34;&gt; &lt;text&gt;CFCs tend to cool the stratosphere both as greenhouse gases and because of their role in destroying ozone and reducing solar absorption.&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34; id=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1_choice_2&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_2&#34;/&gt;&lt;label id=&#34;Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1-choice_2-label&#34; for=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1_choice_2&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34;&gt; &lt;text&gt;CFCs tend to cool the stratosphere as greenhouse gases, but warm it because ozone-destroying reactions are exothermic.&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34; id=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1_choice_3&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_3&#34;/&gt;&lt;label id=&#34;Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1-choice_3-label&#34; for=&#34;input_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1_choice_3&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34;&gt; &lt;text&gt;CFCs tend to warm the stratosphere as greenhouse gases, but cool it because ozone-destroying reactions are endothermic.&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;span id=&#34;answer_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34;/&gt; &lt;/fieldset&gt; &lt;div class=&#34;indicator-container&#34;&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_Ozone-Depleting_Substances_and_Stratospheric_Temperature_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; 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<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@pset_intro" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Problem Set: Geochemistry</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@html+block@Problem_Set_Geochemistry"> <div class="xblock xblock-public_view xblock-public_view-html xmodule_display xmodule_HtmlBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@html+block@Problem_Set_Geochemistry" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="html" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "HTMLModule"} </script> <h2>Geochemistry of climatically-important trace gases in the Earth-system</h2><p>This problem set is aimed at elaborating on why the oceans contain so much more carbon than the atmosphere does, and how the silicate weathering thermostat may regulate Earth's temperature on long time scales. This problem set contains two problems, each of which has multiple parts.</p><p>Problems may ask you to choose the correct answer between a list of alternatives, or may ask you to enter an answer in directly. Be sure to follow the instructions for each problem carefully to ensure you receive full credit for your responses.</p><p>In general you will be allowed two attempts at any multiple choice questions, and three attempts for symbolic or numerical responses, but this will be clearly indicated to you on each problem. Many problems have parts that are dependent on previous answers, and you are encouraged to check that these are correct before you proceed.</p> </div> </div> </div> </div>

<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:pset_p1" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Problem 1: Atmosphere-Ocean Partitioning of Carbon</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@html+block@Problem_1_Atmosphere-Ocean_Partitioning_of_Carbon"> <div class="xblock xblock-public_view xblock-public_view-html xmodule_display xmodule_HtmlBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@html+block@Problem_1_Atmosphere-Ocean_Partitioning_of_Carbon" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="html" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "HTMLModule"} </script> <h2>Problem 1: Atmosphere-Ocean Partitioning of Carbon</h2><p>In this problem we will investigate the partitioning of carbon between the atmosphere and the ocean, and how it depends on pH and temperature. To understand this partitioning, we need to invoke Henry's Law, and know a little bit about the thermodynamics of the dissociation reactions that form the bicarbonate and carbonate ions.</p><p>Henry's Law says that, in equilibrium, the concentration of a dissolved gas in an aqueous solution, [mathjaxinline] [\mbox{X}] [/mathjaxinline] (units: moles of substance per liter of seawater, or mol/L), is linearly proportional to the partial pressure of the gas, [mathjaxinline] p_X [/mathjaxinline] (units: atmospheres, or atm), multiplied by a coefficient, [mathjaxinline] H_X [/mathjaxinline] (units: mol/L/atm), which depends on the gas and the temperature, but not on the pressure or amount of water present:</p> [mathjax] [\mbox{X}] = H_X p_X. [/mathjax] <p>Recall also that a chemical reaction between chemicals [mathjaxinline] \mbox{A} [/mathjaxinline] and [mathjaxinline] \mbox{B} [/mathjaxinline] that combine to form compound [mathjaxinline] \mbox{C} [/mathjaxinline], can be written as:</p> [mathjax] \mbox{A} + \mbox{B} \rightleftharpoons \mbox{C}. [/mathjax] <p>The equilibrium state of this reaction -- where the forward and back reaction rates are equal -- can be characterized by an equilibrium constant [mathjaxinline] K [/mathjaxinline], defined as:</p> [mathjax] K =\frac{[\mbox{C}]}{[\mbox{A}][\mbox{B}]}. [/mathjax] <p>Here, [mathjaxinline] [\mbox{A}] [/mathjaxinline], [mathjaxinline] [\mbox{B}] [/mathjaxinline], and [mathjaxinline] [\mbox{C}] [/mathjaxinline] are concentrations of the reactants and the product (units here: mol/L) in . The equilibrium "constant," of course, is not a universal constant, and generally depends on the temperature and pressure of the system.</p> <p>Also in this problem, we will lump together gaseous dissolved carbon dioxide and carbonic acid, with concentration denoted as [mathjaxinline] [\mbox{CO}_2] [/mathjaxinline].</p> </div> </div> <div class="vert vert-1" data-id="block-v1:MITx+12.340x+1T2020+type@problem+block@ffae381aa74147d78c3071087a2078da"> <div class="xblock xblock-public_view xblock-public_view-problem xmodule_display xmodule_ProblemBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@problem+block@ffae381aa74147d78c3071087a2078da" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="True" data-block-type="problem" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Problem"} </script> <div id="problem_ffae381aa74147d78c3071087a2078da" class="problems-wrapper" role="group" aria-labelledby="ffae381aa74147d78c3071087a2078da-problem-title" data-problem-id="block-v1:MITx+12.340x+1T2020+type@problem+block@ffae381aa74147d78c3071087a2078da" data-url="/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@problem+block@ffae381aa74147d78c3071087a2078da/handler/xmodule_handler" data-problem-score="0.0" data-problem-total-possible="10.0" data-attempts-used="0" data-content=" &lt;h3 class=&#34;hd hd-3 problem-header&#34; id=&#34;ffae381aa74147d78c3071087a2078da-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@ffae381aa74147d78c3071087a2078da-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 1a &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@ffae381aa74147d78c3071087a2078da-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt; &lt;p&gt;Given [mathjaxinline] H_{CO_2} = 3.4 \times 10^{-2} [/mathjaxinline] mol/L/atm at 298 K, and an &lt;b&gt;atmospheric&lt;/b&gt; carbon dioxide concentration of 400 parts per million by volume, what is the equilibrium concentration of dissolved carbon dioxide gas in water at sea level (in units of mol/L)?&lt;/p&gt; &lt;p&gt;Enter your answer below as a number of mol/L. Do not include units in your answer.&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div id=&#34;inputtype_ffae381aa74147d78c3071087a2078da_2_1&#34; class=&#34;text-input-dynamath capa_inputtype textline&#34;&gt; &lt;div class=&#34;unanswered &#34;&gt; &lt;input type=&#34;text&#34; name=&#34;input_ffae381aa74147d78c3071087a2078da_2_1&#34; id=&#34;input_ffae381aa74147d78c3071087a2078da_2_1&#34; aria-describedby=&#34;status_ffae381aa74147d78c3071087a2078da_2_1&#34; value=&#34;&#34; class=&#34;math&#34;/&gt; &lt;span class=&#34;trailing_text&#34; id=&#34;trailing_text_ffae381aa74147d78c3071087a2078da_2_1&#34;/&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_ffae381aa74147d78c3071087a2078da_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;p id=&#34;answer_ffae381aa74147d78c3071087a2078da_2_1&#34; class=&#34;answer&#34;/&gt; &lt;div id=&#34;display_ffae381aa74147d78c3071087a2078da_2_1&#34; class=&#34;equation&#34;&gt;`{::}`&lt;/div&gt; &lt;textarea style=&#34;display:none&#34; id=&#34;input_ffae381aa74147d78c3071087a2078da_2_1_dynamath&#34; name=&#34;input_ffae381aa74147d78c3071087a2078da_2_1_dynamath&#34;/&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_ffae381aa74147d78c3071087a2078da_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;1a&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_ffae381aa74147d78c3071087a2078da&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_ffae381aa74147d78c3071087a2078da&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.&lt;/span&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;problem-action-buttons-wrapper&#34;&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-gentle-alert is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-exclamation-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;ffae381aa74147d78c3071087a2078da-problem-title&#34;&gt; &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-save is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-save&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;ffae381aa74147d78c3071087a2078da-problem-title&#34;&gt;None &lt;/span&gt; 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id=&#34;07deea5b1dbf48a9a957895fbab66bae-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@07deea5b1dbf48a9a957895fbab66bae-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 1b &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@07deea5b1dbf48a9a957895fbab66bae-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt;&lt;p&gt;A gas [mathjaxinline] \mbox{X} [/mathjaxinline] that is well-mixed in the atmosphere has a total atmospheric burden [mathjaxinline] M_{X,atm} [/mathjaxinline] (units: kg) equal to:&lt;/p&gt; [mathjax]M_{X,A} = \frac{m_X p_X}{\overline{m} p_{A}} M_{A},[/mathjax] &lt;p&gt;where [mathjaxinline] p_X/p_A [/mathjaxinline] is the volumetric mixing ratio of the gas (or ratio of its partial pressure to atmospheric pressure), [mathjaxinline] m_X [/mathjaxinline] is the molecular weight of the gas (units kg/mol), [mathjaxinline] \overline{m} [/mathjaxinline] is the average molecular weight of the gases in the atmosphere (about 0.029 kg/mol), and [mathjaxinline] M_A [/mathjaxinline] is the total mass of the atmosphere, about [mathjaxinline] 5.14 \times 10^{18} [/mathjaxinline] kg.&lt;/p&gt; &lt;p&gt;A gas [mathjaxinline] \mbox{X} [/mathjaxinline] that is well-mixed in the ocean has a total oceanic burden [mathjaxinline] M_{X,O} [/mathjaxinline] (units: kg) equal to:&lt;/p&gt; [mathjax]M_{X,O} = m_X [\mbox{X}] V_O,[/mathjax] &lt;p&gt;where [mathjaxinline] [\mbox{X}] [/mathjaxinline] is the concentration of the dissolved gas in water (units mol/L), and [mathjaxinline] V_O [/mathjaxinline] is the volume of the ocean, about [mathjaxinline] 1.4 \times 10^{21} [/mathjaxinline] L.&lt;/p&gt; &lt;p&gt;Assume momentarily that dissolved carbon dioxide does not react with water. Calculate the ratio of oceanic to atmospheric masses of carbon dioxide -- in other words, what is the value of [mathjaxinline] M_{CO_2,O}/M_{CO_2,A} [/mathjaxinline]?&lt;/p&gt; &lt;p&gt;(Note: if masses seem odd for the atmosphere, note that you are calculating masses of carbon dioxide, not of carbon)&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div id=&#34;inputtype_07deea5b1dbf48a9a957895fbab66bae_2_1&#34; class=&#34;text-input-dynamath capa_inputtype textline&#34;&gt; &lt;div class=&#34;unanswered &#34;&gt; &lt;input type=&#34;text&#34; name=&#34;input_07deea5b1dbf48a9a957895fbab66bae_2_1&#34; id=&#34;input_07deea5b1dbf48a9a957895fbab66bae_2_1&#34; aria-describedby=&#34;status_07deea5b1dbf48a9a957895fbab66bae_2_1&#34; value=&#34;&#34; class=&#34;math&#34;/&gt; &lt;span class=&#34;trailing_text&#34; id=&#34;trailing_text_07deea5b1dbf48a9a957895fbab66bae_2_1&#34;/&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_07deea5b1dbf48a9a957895fbab66bae_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;p id=&#34;answer_07deea5b1dbf48a9a957895fbab66bae_2_1&#34; class=&#34;answer&#34;/&gt; &lt;div id=&#34;display_07deea5b1dbf48a9a957895fbab66bae_2_1&#34; class=&#34;equation&#34;&gt;`{::}`&lt;/div&gt; &lt;textarea style=&#34;display:none&#34; id=&#34;input_07deea5b1dbf48a9a957895fbab66bae_2_1_dynamath&#34; name=&#34;input_07deea5b1dbf48a9a957895fbab66bae_2_1_dynamath&#34;/&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_07deea5b1dbf48a9a957895fbab66bae_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;1b&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_07deea5b1dbf48a9a957895fbab66bae&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_07deea5b1dbf48a9a957895fbab66bae&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.&lt;/span&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;problem-action-buttons-wrapper&#34;&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-gentle-alert is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-exclamation-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;07deea5b1dbf48a9a957895fbab66bae-problem-title&#34;&gt; &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-save is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-save&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;07deea5b1dbf48a9a957895fbab66bae-problem-title&#34;&gt;None &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification general notification-show-answer is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-info-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;07deea5b1dbf48a9a957895fbab66bae-problem-title&#34;&gt;Answers are displayed within the problem &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; " data-graded="True"> <p class="loading-spinner"> <i class="fa fa-spinner fa-pulse fa-2x fa-fw"></i> <span class="sr">Loading&hellip;</span> </p> </div> </div> </div> <div class="vert vert-3" data-id="block-v1:MITx+12.340x+1T2020+type@problem+block@9267364b08064086ae04ad49dd3aefbe"> <div class="xblock xblock-public_view xblock-public_view-problem xmodule_display xmodule_ProblemBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@problem+block@9267364b08064086ae04ad49dd3aefbe" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="True" data-block-type="problem" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Problem"} </script> <div id="problem_9267364b08064086ae04ad49dd3aefbe" class="problems-wrapper" role="group" aria-labelledby="9267364b08064086ae04ad49dd3aefbe-problem-title" data-problem-id="block-v1:MITx+12.340x+1T2020+type@problem+block@9267364b08064086ae04ad49dd3aefbe" data-url="/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@problem+block@9267364b08064086ae04ad49dd3aefbe/handler/xmodule_handler" data-problem-score="0.0" data-problem-total-possible="10.0" data-attempts-used="0" data-content=" &lt;h3 class=&#34;hd hd-3 problem-header&#34; id=&#34;9267364b08064086ae04ad49dd3aefbe-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@9267364b08064086ae04ad49dd3aefbe-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 1c &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@9267364b08064086ae04ad49dd3aefbe-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt;&lt;p&gt;Unfortunately for the purposes of the rest of this problem set (though fortunately for the habitability of Earth), carbon dioxide is not inert in water, and thus the atmosphere-ocean partitioning is quite different from what you just estimated. Two reactions in the &#34;carbonate system&#34; and their respective equilibrium constants, are:&lt;/p&gt; [mathjax] \mbox{CO}_2 + \mbox{H}_2\mbox{O}\rightleftharpoons \mbox{HCO}_3^-+\mbox{H}^+, \qquad K_1=\frac{[\mbox{HCO}_3^-][\mbox{H}^+]}{[\mbox{CO}_2]} [/mathjax] &lt;p&gt;and&lt;/p&gt; [mathjax] \mbox{HCO}_3^-\rightleftharpoons \mbox{CO}_3^{2-}+\mbox{H}^+, \qquad K_2=\frac{[\mbox{CO}_3^{2-}][\mbox{H}^+]}{[\mbox{HCO}_3^-]}. [/mathjax] &lt;p&gt;As described in the lectures, carbon dioxide takes part in these two reversible reactions, so the concentration of carbon dioxide stored in the ocean is not just the dissolved gas [mathjaxinline] [\mbox{CO}_2] [/mathjaxinline], but rather:&lt;/p&gt; [mathjax] [\mbox{DIC}] = [\mbox{CO}_2]+[\mbox{HCO}_3^-]+[\mbox{CO}_3^{2-}], [/mathjax] &lt;p&gt;where [mathjaxinline] [\mbox{DIC}] [/mathjaxinline] signifies &#34;dissolved inorganic carbon&#34; (units: mol/L).&lt;/p&gt; &lt;p&gt;Assume a known concentration of hydrogen ions, [mathjaxinline] [\mbox{H}^+] [/mathjaxinline], and use the equilibria of the two reactions above, along with the Henry&#39;s law expression, to solve for for the total dissolved inorganic carbon concentration, [mathjaxinline] [\mbox{DIC}] [/mathjaxinline].&lt;/p&gt; &lt;p&gt;Type your answer in the box below. It should involve the sea level partial pressure of carbon dioxide entered as &#34;p_C&#34;, the hydrogen ion concentration entered as &#34;H&#34;, the Henry&#39;s law coefficient entered as &#34;H_C&#34;, and the two equilibrium coefficients entered as &#34;K_1&#34; and &#34;K_2&#34;. Explicitly indicate any mathematical operations with the appropriate symbol (e.g. &#39;+&#39;, &#39;-&#39;, &#39;*&#39;, &#39;/&#39;, &#39;^&#39;).&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;br/&gt; &lt;span&gt;[mathjaxinline] [\mbox{DIC}] [/mathjaxinline]=&lt;/span&gt; &lt;div id=&#34;inputtype_9267364b08064086ae04ad49dd3aefbe_2_1&#34; class=&#34;text-input-dynamath capa_inputtype textline&#34;&gt; &lt;div class=&#34;unanswered &#34;&gt; &lt;input type=&#34;text&#34; name=&#34;input_9267364b08064086ae04ad49dd3aefbe_2_1&#34; id=&#34;input_9267364b08064086ae04ad49dd3aefbe_2_1&#34; aria-describedby=&#34;status_9267364b08064086ae04ad49dd3aefbe_2_1&#34; value=&#34;&#34; class=&#34;math&#34; size=&#34;40&#34;/&gt; &lt;span class=&#34;trailing_text&#34; id=&#34;trailing_text_9267364b08064086ae04ad49dd3aefbe_2_1&#34;/&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_9267364b08064086ae04ad49dd3aefbe_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;p id=&#34;answer_9267364b08064086ae04ad49dd3aefbe_2_1&#34; class=&#34;answer&#34;/&gt; &lt;div id=&#34;display_9267364b08064086ae04ad49dd3aefbe_2_1&#34; class=&#34;equation&#34;&gt;`{::}`&lt;/div&gt; &lt;textarea style=&#34;display:none&#34; id=&#34;input_9267364b08064086ae04ad49dd3aefbe_2_1_dynamath&#34; name=&#34;input_9267364b08064086ae04ad49dd3aefbe_2_1_dynamath&#34;/&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_9267364b08064086ae04ad49dd3aefbe_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;1c&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_9267364b08064086ae04ad49dd3aefbe&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_9267364b08064086ae04ad49dd3aefbe&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.&lt;/span&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;problem-action-buttons-wrapper&#34;&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-gentle-alert is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-exclamation-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;9267364b08064086ae04ad49dd3aefbe-problem-title&#34;&gt; &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-save is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-save&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;9267364b08064086ae04ad49dd3aefbe-problem-title&#34;&gt;None &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification general notification-show-answer is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-info-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;9267364b08064086ae04ad49dd3aefbe-problem-title&#34;&gt;Answers are displayed within the problem &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; " data-graded="True"> <p class="loading-spinner"> <i class="fa fa-spinner fa-pulse fa-2x fa-fw"></i> <span class="sr">Loading&hellip;</span> </p> </div> </div> </div> <div class="vert vert-4" data-id="block-v1:MITx+12.340x+1T2020+type@problem+block@d4835ccbda134e45b88e260bbda345c4"> <div class="xblock xblock-public_view xblock-public_view-problem xmodule_display xmodule_ProblemBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@problem+block@d4835ccbda134e45b88e260bbda345c4" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="True" data-block-type="problem" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Problem"} </script> <div id="problem_d4835ccbda134e45b88e260bbda345c4" class="problems-wrapper" role="group" aria-labelledby="d4835ccbda134e45b88e260bbda345c4-problem-title" data-problem-id="block-v1:MITx+12.340x+1T2020+type@problem+block@d4835ccbda134e45b88e260bbda345c4" data-url="/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@problem+block@d4835ccbda134e45b88e260bbda345c4/handler/xmodule_handler" data-problem-score="0.0" data-problem-total-possible="10.0" data-attempts-used="0" data-content=" &lt;h3 class=&#34;hd hd-3 problem-header&#34; id=&#34;d4835ccbda134e45b88e260bbda345c4-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@d4835ccbda134e45b88e260bbda345c4-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 1d &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@d4835ccbda134e45b88e260bbda345c4-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt; &lt;p&gt;Now, let&#39;s return to the question from part B. What is the ratio of total dissolved inorganic carbon to atmospheric carbon? Note that the result from part C can be incorporated by just replacing the value of the Henry&#39;s law coefficient in the answer to B with a different value that now depends on pH (hydrogen ion concentration) and the equilibrium constants [mathjaxinline] K_1 [/mathjaxinline] and [mathjaxinline] K_2 [/mathjaxinline]. Feel free to check the answers to 1B and 1C before doing this question.&lt;/p&gt; &lt;p&gt;To answer this question, assume that [mathjaxinline] [\mbox{H}^+] = 10^{-8.2} = 6.3 \times 10^{-9} [/mathjaxinline] mol/L (a pH of 8.2), that [mathjaxinline] K_1 = 4.3 \times 10^{-7} [/mathjaxinline] mol/L, and [mathjaxinline] K_2 = 4.7 \times 10^{-11} [/mathjaxinline] mol/L. Calculate the ratio of total dissolved inorganic carbon in the ocean to atmospheric carbon.&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div id=&#34;inputtype_d4835ccbda134e45b88e260bbda345c4_2_1&#34; class=&#34;text-input-dynamath capa_inputtype textline&#34;&gt; &lt;div class=&#34;unanswered &#34;&gt; &lt;input type=&#34;text&#34; name=&#34;input_d4835ccbda134e45b88e260bbda345c4_2_1&#34; id=&#34;input_d4835ccbda134e45b88e260bbda345c4_2_1&#34; aria-describedby=&#34;status_d4835ccbda134e45b88e260bbda345c4_2_1&#34; value=&#34;&#34; class=&#34;math&#34;/&gt; &lt;span class=&#34;trailing_text&#34; id=&#34;trailing_text_d4835ccbda134e45b88e260bbda345c4_2_1&#34;/&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_d4835ccbda134e45b88e260bbda345c4_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;p id=&#34;answer_d4835ccbda134e45b88e260bbda345c4_2_1&#34; class=&#34;answer&#34;/&gt; &lt;div id=&#34;display_d4835ccbda134e45b88e260bbda345c4_2_1&#34; class=&#34;equation&#34;&gt;`{::}`&lt;/div&gt; &lt;textarea style=&#34;display:none&#34; id=&#34;input_d4835ccbda134e45b88e260bbda345c4_2_1_dynamath&#34; name=&#34;input_d4835ccbda134e45b88e260bbda345c4_2_1_dynamath&#34;/&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_d4835ccbda134e45b88e260bbda345c4_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;1d&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_d4835ccbda134e45b88e260bbda345c4&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_d4835ccbda134e45b88e260bbda345c4&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.&lt;/span&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;problem-action-buttons-wrapper&#34;&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-gentle-alert is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-exclamation-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;d4835ccbda134e45b88e260bbda345c4-problem-title&#34;&gt; &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-save is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-save&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;d4835ccbda134e45b88e260bbda345c4-problem-title&#34;&gt;None &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification general notification-show-answer is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-info-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;d4835ccbda134e45b88e260bbda345c4-problem-title&#34;&gt;Answers are displayed within the problem &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; " data-graded="True"> <p class="loading-spinner"> <i class="fa fa-spinner fa-pulse fa-2x fa-fw"></i> <span class="sr">Loading&hellip;</span> </p> </div> </div> </div> <div class="vert vert-5" data-id="block-v1:MITx+12.340x+1T2020+type@problem+block@26c5c274e0044de6be8b6cfa50db5931"> <div class="xblock xblock-public_view xblock-public_view-problem xmodule_display xmodule_ProblemBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@problem+block@26c5c274e0044de6be8b6cfa50db5931" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="True" data-block-type="problem" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Problem"} </script> <div id="problem_26c5c274e0044de6be8b6cfa50db5931" class="problems-wrapper" role="group" aria-labelledby="26c5c274e0044de6be8b6cfa50db5931-problem-title" data-problem-id="block-v1:MITx+12.340x+1T2020+type@problem+block@26c5c274e0044de6be8b6cfa50db5931" data-url="/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@problem+block@26c5c274e0044de6be8b6cfa50db5931/handler/xmodule_handler" data-problem-score="0.0" data-problem-total-possible="10.0" data-attempts-used="0" data-content=" &lt;h3 class=&#34;hd hd-3 problem-header&#34; id=&#34;26c5c274e0044de6be8b6cfa50db5931-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@26c5c274e0044de6be8b6cfa50db5931-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 1e &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@26c5c274e0044de6be8b6cfa50db5931-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt; &lt;p&gt;So we see that for the assumptions just made, the mass of dissolved inorganic carbon in the ocean is much larger than the mass of gaseous carbon dioxide in the atmosphere. But how strongly does this depend on pH? Recall that pH is defined as [mathjaxinline]\mbox{pH} = -log_{10}([\mbox{H}^+]) [/mathjaxinline].&lt;/p&gt; &lt;p&gt;What would the ratio of oceanic dissolved inorganic carbon to atmospheric carbon be for a neutral ocean, with a pH of 7.0?&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div id=&#34;inputtype_26c5c274e0044de6be8b6cfa50db5931_2_1&#34; class=&#34;text-input-dynamath capa_inputtype textline&#34;&gt; &lt;div class=&#34;unanswered &#34;&gt; &lt;input type=&#34;text&#34; name=&#34;input_26c5c274e0044de6be8b6cfa50db5931_2_1&#34; id=&#34;input_26c5c274e0044de6be8b6cfa50db5931_2_1&#34; aria-describedby=&#34;status_26c5c274e0044de6be8b6cfa50db5931_2_1&#34; value=&#34;&#34; class=&#34;math&#34;/&gt; &lt;span class=&#34;trailing_text&#34; id=&#34;trailing_text_26c5c274e0044de6be8b6cfa50db5931_2_1&#34;/&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_26c5c274e0044de6be8b6cfa50db5931_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;p id=&#34;answer_26c5c274e0044de6be8b6cfa50db5931_2_1&#34; class=&#34;answer&#34;/&gt; &lt;div id=&#34;display_26c5c274e0044de6be8b6cfa50db5931_2_1&#34; class=&#34;equation&#34;&gt;`{::}`&lt;/div&gt; &lt;textarea style=&#34;display:none&#34; id=&#34;input_26c5c274e0044de6be8b6cfa50db5931_2_1_dynamath&#34; name=&#34;input_26c5c274e0044de6be8b6cfa50db5931_2_1_dynamath&#34;/&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_26c5c274e0044de6be8b6cfa50db5931_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;1e&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_26c5c274e0044de6be8b6cfa50db5931&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_26c5c274e0044de6be8b6cfa50db5931&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.&lt;/span&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;problem-action-buttons-wrapper&#34;&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-gentle-alert is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-exclamation-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;26c5c274e0044de6be8b6cfa50db5931-problem-title&#34;&gt; &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-save is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-save&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;26c5c274e0044de6be8b6cfa50db5931-problem-title&#34;&gt;None &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification general notification-show-answer is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-info-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;26c5c274e0044de6be8b6cfa50db5931-problem-title&#34;&gt;Answers are displayed within the problem &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; " data-graded="True"> <p class="loading-spinner"> <i class="fa fa-spinner fa-pulse fa-2x fa-fw"></i> <span class="sr">Loading&hellip;</span> </p> </div> </div> </div> <div class="vert vert-6" data-id="block-v1:MITx+12.340x+1T2020+type@problem+block@01e2d34791ea433dbe7bf0101efc8b82"> <div class="xblock xblock-public_view xblock-public_view-problem xmodule_display xmodule_ProblemBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@problem+block@01e2d34791ea433dbe7bf0101efc8b82" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="True" data-block-type="problem" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Problem"} </script> <div id="problem_01e2d34791ea433dbe7bf0101efc8b82" class="problems-wrapper" role="group" aria-labelledby="01e2d34791ea433dbe7bf0101efc8b82-problem-title" data-problem-id="block-v1:MITx+12.340x+1T2020+type@problem+block@01e2d34791ea433dbe7bf0101efc8b82" data-url="/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@problem+block@01e2d34791ea433dbe7bf0101efc8b82/handler/xmodule_handler" data-problem-score="0.0" data-problem-total-possible="10.0" data-attempts-used="0" data-content=" &lt;h3 class=&#34;hd hd-3 problem-header&#34; id=&#34;01e2d34791ea433dbe7bf0101efc8b82-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@01e2d34791ea433dbe7bf0101efc8b82-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 1f &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@01e2d34791ea433dbe7bf0101efc8b82-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt;&lt;p&gt;Temperature-dependence is more complicated; all three of the &#34;constants&#34; [mathjaxinline]H_{CO_2}[/mathjaxinline], [mathjaxinline]K_1[/mathjaxinline], and [mathjaxinline]K_2[/mathjaxinline], depend on temperature, as does the pH of pure water. Furthermore, the temperature-dependencies don&#39;t all go in the same direction; carbon dioxide is less soluble in warmer water, but dissociates more readily into bicarbonate and carbonate ions. For the sake of this problem, we&#39;re only going to consider the dependence of carbon dioxide solubility (i.e., the Henry&#39;s law coefficient) on temperature.&lt;/p&gt;&lt;p&gt;A physically well-founded approximation for the dependence of the solubility of carbon dioxide on temperature is given by:&lt;/p&gt; [mathjax] H_{CO_2}(T) = H_{CO_2}(T_{ref}) \cdot \exp \left[-8.053\left(1-\frac{T_{ref}}{T}\right)\right], [/mathjax] &lt;p&gt;which related the Henry&#39;s law coefficient at temperature [mathjaxinline]T[/mathjaxinline] to the Henry&#39;s law coefficient at a reference temperature [mathjaxinline]T_{ref}[/mathjaxinline], which is for our purposes 298 K. What is the ratio of the amount of dissolved carbon dioxide gas that can be held by water at 275 K, as compared to water at 298 K?&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div id=&#34;inputtype_01e2d34791ea433dbe7bf0101efc8b82_2_1&#34; class=&#34;text-input-dynamath capa_inputtype textline&#34;&gt; &lt;div class=&#34;unanswered &#34;&gt; &lt;input type=&#34;text&#34; name=&#34;input_01e2d34791ea433dbe7bf0101efc8b82_2_1&#34; id=&#34;input_01e2d34791ea433dbe7bf0101efc8b82_2_1&#34; aria-describedby=&#34;status_01e2d34791ea433dbe7bf0101efc8b82_2_1&#34; value=&#34;&#34; class=&#34;math&#34;/&gt; &lt;span class=&#34;trailing_text&#34; id=&#34;trailing_text_01e2d34791ea433dbe7bf0101efc8b82_2_1&#34;/&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_01e2d34791ea433dbe7bf0101efc8b82_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;p id=&#34;answer_01e2d34791ea433dbe7bf0101efc8b82_2_1&#34; class=&#34;answer&#34;/&gt; &lt;div id=&#34;display_01e2d34791ea433dbe7bf0101efc8b82_2_1&#34; class=&#34;equation&#34;&gt;`{::}`&lt;/div&gt; &lt;textarea style=&#34;display:none&#34; id=&#34;input_01e2d34791ea433dbe7bf0101efc8b82_2_1_dynamath&#34; name=&#34;input_01e2d34791ea433dbe7bf0101efc8b82_2_1_dynamath&#34;/&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_01e2d34791ea433dbe7bf0101efc8b82_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;1f&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_01e2d34791ea433dbe7bf0101efc8b82&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_01e2d34791ea433dbe7bf0101efc8b82&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.&lt;/span&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;problem-action-buttons-wrapper&#34;&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-gentle-alert is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-exclamation-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;01e2d34791ea433dbe7bf0101efc8b82-problem-title&#34;&gt; &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-save is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-save&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;01e2d34791ea433dbe7bf0101efc8b82-problem-title&#34;&gt;None &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification general notification-show-answer is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-info-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;01e2d34791ea433dbe7bf0101efc8b82-problem-title&#34;&gt;Answers are displayed within the problem &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; " data-graded="True"> <p class="loading-spinner"> <i class="fa fa-spinner fa-pulse fa-2x fa-fw"></i> <span class="sr">Loading&hellip;</span> </p> </div> </div> </div> </div> </div>

<div class="xblock xblock-public_view xblock-public_view-vertical" data-usage-id="block-v1:MITx+12.340x+1T2020+type@vertical+block@Geochem:pset_p2" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="vertical" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="VerticalStudentView"> <h2 class="hd hd-2 unit-title">Problem 2: The Faint Young Sun and the Weathering Thermostat</h2> <div class="vert-mod"> <div class="vert vert-0" data-id="block-v1:MITx+12.340x+1T2020+type@html+block@Problem_2_The_Faint_Young_Sun_and_the_Weathering_Thermostat"> <div class="xblock xblock-public_view xblock-public_view-html xmodule_display xmodule_HtmlBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@html+block@Problem_2_The_Faint_Young_Sun_and_the_Weathering_Thermostat" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="False" data-block-type="html" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "HTMLModule"} </script> <h2>Problem 2: The Faint Young Sun and the Weathering Thermostat</h2><p>In this problem we will explore in a bit more detail the "Faint Young Sun Paradox," and how the feedback between silicate weathering and temperature can act as a "thermostat" on Earth's climate on long time scales.</p><p>Since we will be considering a number of variables to have changed from the present, we will try to use consistent notation; an un-subscripted variable will mean the value of the variable at some past time, and a variable subscripted with [mathjaxinline] _0 [/mathjaxinline] will mean its value at present. For example, Earth's mean temperature at some point in the past will be [mathjaxinline] T [/mathjaxinline], and its current temperature will be [mathjaxinline] T_0 [/mathjaxinline]. We will use [mathjaxinline] S [/mathjaxinline] to indicate solar irradiance at Earth's orbital distance, and [mathjaxinline] C [/mathjaxinline] to indicate carbon dioxide concentrations in the atmosphere.</p> </div> </div> <div class="vert vert-1" data-id="block-v1:MITx+12.340x+1T2020+type@problem+block@c11615b526634c648ff7e02829ee0437"> <div class="xblock xblock-public_view xblock-public_view-problem xmodule_display xmodule_ProblemBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@problem+block@c11615b526634c648ff7e02829ee0437" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="True" data-block-type="problem" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Problem"} </script> <div id="problem_c11615b526634c648ff7e02829ee0437" class="problems-wrapper" role="group" aria-labelledby="c11615b526634c648ff7e02829ee0437-problem-title" data-problem-id="block-v1:MITx+12.340x+1T2020+type@problem+block@c11615b526634c648ff7e02829ee0437" data-url="/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@problem+block@c11615b526634c648ff7e02829ee0437/handler/xmodule_handler" data-problem-score="0.0" data-problem-total-possible="10.0" data-attempts-used="0" data-content=" &lt;h3 class=&#34;hd hd-3 problem-header&#34; id=&#34;c11615b526634c648ff7e02829ee0437-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@c11615b526634c648ff7e02829ee0437-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 2a &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@c11615b526634c648ff7e02829ee0437-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt;&lt;p&gt;Suppose that an expression for the temperature deviation from the current state is given by:&lt;/p&gt; [mathjax] T-T_0 = \frac{1}{\lambda} \left[ (5.37\textrm{ W/m}^2) \ln{(C/C_0)} + \frac{(1-\alpha)S_0}{4}(S/S_0 - 1)\right], [/mathjax] &lt;p&gt;where the term in square brackets is a &#34;radiative forcing,&#34; or perturbation in energy supply from the present climate (more on this in week 11!), and the parameter [mathjaxinline] \lambda [/mathjaxinline] is a &#34;total feedback parameter&#34;. [mathjaxinline]\lambda[/mathjaxinline] represents the increase in outgoing radiation from the Earth that occurs for a unit change in surface temperature (units: W/m&lt;sup&gt;2&lt;/sup&gt;/K). We will take [mathjaxinline] \lambda = 1.5 [/mathjaxinline] W/m&lt;sup&gt;2&lt;/sup&gt;/K for the rest of this problem.&lt;/p&gt; &lt;p&gt;Now, we want to estimate how much cooler the Earth would have been early in its history, when the sun was much weaker, say [mathjaxinline] S/S_0 = 0.85 [/mathjaxinline]. A weakening in solar luminosity by 15% corresponds to about 2 billion years ago. Assume a constant planetary albedo of [mathjaxinline]\alpha=0.30[/mathjaxinline], and that the current solar constant is [mathjaxinline]S_0=1360[/mathjaxinline] W/m&lt;sup&gt;2&lt;/sup&gt;. If carbon dioxide concentrations were unchanged (i.e., [mathjaxinline] C/C_0 = 1.0 [/mathjaxinline], how much cooler would the earth have been, in Kelvin? (Note: please answer with a positive number giving the magnitude of how much cooler the Earth would be; do not include units in your answer.)&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div id=&#34;inputtype_c11615b526634c648ff7e02829ee0437_2_1&#34; class=&#34;text-input-dynamath capa_inputtype textline&#34;&gt; &lt;div class=&#34;unanswered &#34;&gt; &lt;input type=&#34;text&#34; name=&#34;input_c11615b526634c648ff7e02829ee0437_2_1&#34; id=&#34;input_c11615b526634c648ff7e02829ee0437_2_1&#34; aria-describedby=&#34;status_c11615b526634c648ff7e02829ee0437_2_1&#34; value=&#34;&#34; class=&#34;math&#34;/&gt; &lt;span class=&#34;trailing_text&#34; id=&#34;trailing_text_c11615b526634c648ff7e02829ee0437_2_1&#34;/&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_c11615b526634c648ff7e02829ee0437_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;p id=&#34;answer_c11615b526634c648ff7e02829ee0437_2_1&#34; class=&#34;answer&#34;/&gt; &lt;div id=&#34;display_c11615b526634c648ff7e02829ee0437_2_1&#34; class=&#34;equation&#34;&gt;`{::}`&lt;/div&gt; &lt;textarea style=&#34;display:none&#34; id=&#34;input_c11615b526634c648ff7e02829ee0437_2_1_dynamath&#34; name=&#34;input_c11615b526634c648ff7e02829ee0437_2_1_dynamath&#34;/&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_c11615b526634c648ff7e02829ee0437_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;2a&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_c11615b526634c648ff7e02829ee0437&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_c11615b526634c648ff7e02829ee0437&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.&lt;/span&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;problem-action-buttons-wrapper&#34;&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-gentle-alert is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-exclamation-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;c11615b526634c648ff7e02829ee0437-problem-title&#34;&gt; &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-save is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-save&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;c11615b526634c648ff7e02829ee0437-problem-title&#34;&gt;None &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification general notification-show-answer is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-info-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;c11615b526634c648ff7e02829ee0437-problem-title&#34;&gt;Answers are displayed within the problem &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; " data-graded="True"> <p class="loading-spinner"> <i class="fa fa-spinner fa-pulse fa-2x fa-fw"></i> <span class="sr">Loading&hellip;</span> </p> </div> </div> </div> <div class="vert vert-2" data-id="block-v1:MITx+12.340x+1T2020+type@problem+block@3490bfb4fea647489ab115100c49b7b1"> <div class="xblock xblock-public_view xblock-public_view-problem xmodule_display xmodule_ProblemBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@problem+block@3490bfb4fea647489ab115100c49b7b1" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="True" data-block-type="problem" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Problem"} </script> <div id="problem_3490bfb4fea647489ab115100c49b7b1" class="problems-wrapper" role="group" aria-labelledby="3490bfb4fea647489ab115100c49b7b1-problem-title" data-problem-id="block-v1:MITx+12.340x+1T2020+type@problem+block@3490bfb4fea647489ab115100c49b7b1" data-url="/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@problem+block@3490bfb4fea647489ab115100c49b7b1/handler/xmodule_handler" data-problem-score="0.0" data-problem-total-possible="10.0" data-attempts-used="0" data-content=" &lt;h3 class=&#34;hd hd-3 problem-header&#34; id=&#34;3490bfb4fea647489ab115100c49b7b1-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@3490bfb4fea647489ab115100c49b7b1-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 2b &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@3490bfb4fea647489ab115100c49b7b1-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt; &lt;p&gt;This much cooling from the present, of course, would plunge the Earth&#39;s mean temperature well below freezing, with sea ice increasing the albedo of the Earth, and dropping the temperature even more! So how much carbon dioxide do we need to keep the Earth from freezing? Calculate the ratio of past to present carbon dioxide concentrations, [mathjaxinline] C/C_0 [/mathjaxinline], that would be required to keep Earth&#39;s temperature constant with [mathjaxinline] S/S_0 = 0.85 [/mathjaxinline].&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div id=&#34;inputtype_3490bfb4fea647489ab115100c49b7b1_2_1&#34; class=&#34;text-input-dynamath capa_inputtype textline&#34;&gt; &lt;div class=&#34;unanswered &#34;&gt; &lt;input type=&#34;text&#34; name=&#34;input_3490bfb4fea647489ab115100c49b7b1_2_1&#34; id=&#34;input_3490bfb4fea647489ab115100c49b7b1_2_1&#34; aria-describedby=&#34;status_3490bfb4fea647489ab115100c49b7b1_2_1&#34; value=&#34;&#34; class=&#34;math&#34;/&gt; &lt;span class=&#34;trailing_text&#34; id=&#34;trailing_text_3490bfb4fea647489ab115100c49b7b1_2_1&#34;/&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_3490bfb4fea647489ab115100c49b7b1_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;p id=&#34;answer_3490bfb4fea647489ab115100c49b7b1_2_1&#34; class=&#34;answer&#34;/&gt; &lt;div id=&#34;display_3490bfb4fea647489ab115100c49b7b1_2_1&#34; class=&#34;equation&#34;&gt;`{::}`&lt;/div&gt; &lt;textarea style=&#34;display:none&#34; id=&#34;input_3490bfb4fea647489ab115100c49b7b1_2_1_dynamath&#34; name=&#34;input_3490bfb4fea647489ab115100c49b7b1_2_1_dynamath&#34;/&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_3490bfb4fea647489ab115100c49b7b1_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;2b&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_3490bfb4fea647489ab115100c49b7b1&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_3490bfb4fea647489ab115100c49b7b1&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.&lt;/span&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;problem-action-buttons-wrapper&#34;&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-gentle-alert is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-exclamation-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;3490bfb4fea647489ab115100c49b7b1-problem-title&#34;&gt; &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-save is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-save&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;3490bfb4fea647489ab115100c49b7b1-problem-title&#34;&gt;None &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification general notification-show-answer is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-info-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;3490bfb4fea647489ab115100c49b7b1-problem-title&#34;&gt;Answers are displayed within the problem &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; " data-graded="True"> <p class="loading-spinner"> <i class="fa fa-spinner fa-pulse fa-2x fa-fw"></i> <span class="sr">Loading&hellip;</span> </p> </div> </div> </div> <div class="vert vert-3" data-id="block-v1:MITx+12.340x+1T2020+type@problem+block@a9b8615895d549048464b34c1cc1fb37"> <div class="xblock xblock-public_view xblock-public_view-problem xmodule_display xmodule_ProblemBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@problem+block@a9b8615895d549048464b34c1cc1fb37" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="True" data-block-type="problem" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Problem"} </script> <div id="problem_a9b8615895d549048464b34c1cc1fb37" class="problems-wrapper" role="group" aria-labelledby="a9b8615895d549048464b34c1cc1fb37-problem-title" data-problem-id="block-v1:MITx+12.340x+1T2020+type@problem+block@a9b8615895d549048464b34c1cc1fb37" data-url="/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@problem+block@a9b8615895d549048464b34c1cc1fb37/handler/xmodule_handler" data-problem-score="0.0" data-problem-total-possible="10.0" data-attempts-used="0" data-content=" &lt;h3 class=&#34;hd hd-3 problem-header&#34; id=&#34;a9b8615895d549048464b34c1cc1fb37-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@a9b8615895d549048464b34c1cc1fb37-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 2c &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@a9b8615895d549048464b34c1cc1fb37-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt;&lt;p&gt;The idea of the &#34;weathering thermostat&#34;, as described in the lecture clips, is that carbon dioxide has decreased over Earth&#39;s history, as the solar output has increased. We can write an equation for the rate of change of mass of total carbon [mathjaxinline] C_T [/mathjaxinline] in the near-surface system (including ocean, atmosphere, and terrestrial biosphere), as:&lt;/p&gt; [mathjax] \frac{d C_T}{dt} = V - W, [/mathjax] &lt;p&gt;where [mathjaxinline] V [/mathjaxinline] is the rate of volcanic input, and [mathjaxinline] W [/mathjaxinline] is the rate of removal by weathering. Given a constant volcanic forcing, which of the following statements must be true in order for the mass of near-surface carbon to be dynamically stable?&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div class=&#34;choicegroup capa_inputtype&#34; id=&#34;inputtype_a9b8615895d549048464b34c1cc1fb37_2_1&#34;&gt; &lt;fieldset aria-describedby=&#34;status_a9b8615895d549048464b34c1cc1fb37_2_1&#34;&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1&#34; id=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_0&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_0&#34;/&gt;&lt;label id=&#34;a9b8615895d549048464b34c1cc1fb37_2_1-choice_0-label&#34; for=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_0&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_a9b8615895d549048464b34c1cc1fb37_2_1&#34;&gt; &lt;text&gt;The second derivative of [mathjaxinline] W [/mathjaxinline] with respect to [mathjaxinline] C_T [/mathjaxinline] must be negative&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1&#34; id=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_1&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_1&#34;/&gt;&lt;label id=&#34;a9b8615895d549048464b34c1cc1fb37_2_1-choice_1-label&#34; for=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_1&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_a9b8615895d549048464b34c1cc1fb37_2_1&#34;&gt; &lt;text&gt;The second derivative of [mathjaxinline] W [/mathjaxinline] with respect to [mathjaxinline] C_T [/mathjaxinline] must be zero&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1&#34; id=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_2&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_2&#34;/&gt;&lt;label id=&#34;a9b8615895d549048464b34c1cc1fb37_2_1-choice_2-label&#34; for=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_2&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_a9b8615895d549048464b34c1cc1fb37_2_1&#34;&gt; &lt;text&gt;The second derivative of [mathjaxinline] W [/mathjaxinline] with respect to [mathjaxinline] C_T [/mathjaxinline] must be positive&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1&#34; id=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_3&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_3&#34;/&gt;&lt;label id=&#34;a9b8615895d549048464b34c1cc1fb37_2_1-choice_3-label&#34; for=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_3&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_a9b8615895d549048464b34c1cc1fb37_2_1&#34;&gt; &lt;text&gt;The first derivative of [mathjaxinline] W [/mathjaxinline] with respect to [mathjaxinline] C_T [/mathjaxinline] must be negative&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1&#34; id=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_4&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_4&#34;/&gt;&lt;label id=&#34;a9b8615895d549048464b34c1cc1fb37_2_1-choice_4-label&#34; for=&#34;input_a9b8615895d549048464b34c1cc1fb37_2_1_choice_4&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_a9b8615895d549048464b34c1cc1fb37_2_1&#34;&gt; &lt;text&gt;The first derivative of [mathjaxinline] W [/mathjaxinline] with respect to [mathjaxinline] C_T [/mathjaxinline] must be positive&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;span id=&#34;answer_a9b8615895d549048464b34c1cc1fb37_2_1&#34;/&gt; &lt;/fieldset&gt; &lt;div class=&#34;indicator-container&#34;&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_a9b8615895d549048464b34c1cc1fb37_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_a9b8615895d549048464b34c1cc1fb37_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;2c&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_a9b8615895d549048464b34c1cc1fb37&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_a9b8615895d549048464b34c1cc1fb37&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. 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[/mathjax] &lt;p&gt;The strength of the weathering dependence on carbon dioxide concentration and temperature is given by the parameters [mathjaxinline]a=0.30[/mathjaxinline] and [mathjaxinline]b=0.073[/mathjaxinline]. Using the model from part A for temperature perturbation, this expression for weathering ratio can be expressed in terms of the ratio of past to present carbon dioxide and solar brightness:&lt;/p&gt; [mathjax] W/W_0 = (C/C_0)^{0.56}\cdot \exp{\left[11.6\left(\frac{S}{S_0}-1\right)\right]}. [/mathjax] &lt;p&gt;According to the equation given in part C, a quasi-steady state can only be acheived if the weathering rate balances the source of carbon dioxide owing to volcanism. Here, we make the very simple assumption that the rate of volcanism of the early Earth is the same as it is at present. This implies that the weathering rate was also equal to its present value. Under these conditions, what is the ratio of the concentration of carbon dioxide at the time that the sun was 15% dimmer than present compared to the carbon dioxide concentration in the present day? In other words, solve for the value of [mathjaxinline] C/C_0 [/mathjaxinline] consistent with [mathjaxinline] W/W_0 = 1.0 [/mathjaxinline] and [mathjaxinline] S/S_0 = 0.85 [/mathjaxinline].&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div id=&#34;inputtype_b253922c8ed64b37949bbb8c09aee618_2_1&#34; class=&#34;text-input-dynamath capa_inputtype textline&#34;&gt; &lt;div class=&#34;unanswered &#34;&gt; &lt;input type=&#34;text&#34; name=&#34;input_b253922c8ed64b37949bbb8c09aee618_2_1&#34; id=&#34;input_b253922c8ed64b37949bbb8c09aee618_2_1&#34; aria-describedby=&#34;status_b253922c8ed64b37949bbb8c09aee618_2_1&#34; value=&#34;&#34; class=&#34;math&#34;/&gt; &lt;span class=&#34;trailing_text&#34; id=&#34;trailing_text_b253922c8ed64b37949bbb8c09aee618_2_1&#34;/&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_b253922c8ed64b37949bbb8c09aee618_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;p id=&#34;answer_b253922c8ed64b37949bbb8c09aee618_2_1&#34; class=&#34;answer&#34;/&gt; &lt;div id=&#34;display_b253922c8ed64b37949bbb8c09aee618_2_1&#34; class=&#34;equation&#34;&gt;`{::}`&lt;/div&gt; &lt;textarea style=&#34;display:none&#34; id=&#34;input_b253922c8ed64b37949bbb8c09aee618_2_1_dynamath&#34; name=&#34;input_b253922c8ed64b37949bbb8c09aee618_2_1_dynamath&#34;/&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_b253922c8ed64b37949bbb8c09aee618_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;2d&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_b253922c8ed64b37949bbb8c09aee618&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_b253922c8ed64b37949bbb8c09aee618&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.&lt;/span&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;problem-action-buttons-wrapper&#34;&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-gentle-alert is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-exclamation-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;b253922c8ed64b37949bbb8c09aee618-problem-title&#34;&gt; &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification warning notification-save is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-save&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;b253922c8ed64b37949bbb8c09aee618-problem-title&#34;&gt;None &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&#34;notification general notification-show-answer is-hidden&#34; tabindex=&#34;-1&#34;&gt; &lt;span class=&#34;icon fa fa-info-circle&#34; aria-hidden=&#34;true&#34;&gt;&lt;/span&gt; &lt;span class=&#34;notification-message&#34; aria-describedby=&#34;b253922c8ed64b37949bbb8c09aee618-problem-title&#34;&gt;Answers are displayed within the problem &lt;/span&gt; &lt;div class=&#34;notification-btn-wrapper&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;btn btn-default btn-small notification-btn review-btn sr&#34;&gt;Review&lt;/button&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt; " data-graded="True"> <p class="loading-spinner"> <i class="fa fa-spinner fa-pulse fa-2x fa-fw"></i> <span class="sr">Loading&hellip;</span> </p> </div> </div> </div> <div class="vert vert-5" data-id="block-v1:MITx+12.340x+1T2020+type@problem+block@29f1bfc3b77a4a89aee8fe149805bc98"> <div class="xblock xblock-public_view xblock-public_view-problem xmodule_display xmodule_ProblemBlock" data-usage-id="block-v1:MITx+12.340x+1T2020+type@problem+block@29f1bfc3b77a4a89aee8fe149805bc98" data-course-id="course-v1:MITx+12.340x+1T2020" data-runtime-class="LmsRuntime" data-has-score="True" data-block-type="problem" data-runtime-version="1" data-request-token="78179e62dbd911ef904f12ab06d4b43d" data-graded="True" data-init="XBlockToXModuleShim"> <script type="json/xblock-args" class="xblock-json-init-args"> {"xmodule-type": "Problem"} </script> <div id="problem_29f1bfc3b77a4a89aee8fe149805bc98" class="problems-wrapper" role="group" aria-labelledby="29f1bfc3b77a4a89aee8fe149805bc98-problem-title" data-problem-id="block-v1:MITx+12.340x+1T2020+type@problem+block@29f1bfc3b77a4a89aee8fe149805bc98" data-url="/courses/course-v1:MITx+12.340x+1T2020/xblock/block-v1:MITx+12.340x+1T2020+type@problem+block@29f1bfc3b77a4a89aee8fe149805bc98/handler/xmodule_handler" data-problem-score="0.0" data-problem-total-possible="10.0" data-attempts-used="0" data-content=" &lt;h3 class=&#34;hd hd-3 problem-header&#34; id=&#34;29f1bfc3b77a4a89aee8fe149805bc98-problem-title&#34; aria-describedby=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@29f1bfc3b77a4a89aee8fe149805bc98-problem-progress&#34; tabindex=&#34;-1&#34;&gt; 2e &lt;/h3&gt; &lt;div class=&#34;problem-progress&#34; id=&#34;block-v1:MITx+12.340x+1T2020+type@problem+block@29f1bfc3b77a4a89aee8fe149805bc98-problem-progress&#34;&gt;&lt;/div&gt; &lt;div class=&#34;problem&#34;&gt; &lt;div&gt; &lt;span&gt; &lt;p&gt;Based on the answer from part D, and the model of temperature change in part A, approximately how much does the weathering feedback described here compensate for solar dimming? In other words, by what fraction is the cooling predicted in part A reduced by including the weathering feedback?&lt;/p&gt; &lt;/span&gt; &lt;div class=&#34;wrapper-problem-response&#34; tabindex=&#34;-1&#34; aria-label=&#34;Question 1&#34; role=&#34;group&#34;&gt;&lt;div class=&#34;choicegroup capa_inputtype&#34; id=&#34;inputtype_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34;&gt; &lt;fieldset aria-describedby=&#34;status_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34;&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34; id=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_0&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_0&#34;/&gt;&lt;label id=&#34;29f1bfc3b77a4a89aee8fe149805bc98_2_1-choice_0-label&#34; for=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_0&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34;&gt; &lt;text&gt;about 10%&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34; id=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_1&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_1&#34;/&gt;&lt;label id=&#34;29f1bfc3b77a4a89aee8fe149805bc98_2_1-choice_1-label&#34; for=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_1&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34;&gt; &lt;text&gt;about 50%&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34; id=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_2&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_2&#34;/&gt;&lt;label id=&#34;29f1bfc3b77a4a89aee8fe149805bc98_2_1-choice_2-label&#34; for=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_2&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34;&gt; &lt;text&gt;about 75%&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34; id=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_3&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_3&#34;/&gt;&lt;label id=&#34;29f1bfc3b77a4a89aee8fe149805bc98_2_1-choice_3-label&#34; for=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_3&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34;&gt; &lt;text&gt;about 95%&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;div class=&#34;field&#34;&gt; &lt;input type=&#34;radio&#34; name=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34; id=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_4&#34; class=&#34;field-input input-radio&#34; value=&#34;choice_4&#34;/&gt;&lt;label id=&#34;29f1bfc3b77a4a89aee8fe149805bc98_2_1-choice_4-label&#34; for=&#34;input_29f1bfc3b77a4a89aee8fe149805bc98_2_1_choice_4&#34; class=&#34;response-label field-label label-inline&#34; aria-describedby=&#34;status_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34;&gt; &lt;text&gt;over 99%&lt;/text&gt; &lt;/label&gt; &lt;/div&gt; &lt;span id=&#34;answer_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34;/&gt; &lt;/fieldset&gt; &lt;div class=&#34;indicator-container&#34;&gt; &lt;span class=&#34;status unanswered&#34; id=&#34;status_29f1bfc3b77a4a89aee8fe149805bc98_2_1&#34; data-tooltip=&#34;Not yet answered.&#34;&gt; &lt;span class=&#34;sr&#34;&gt;unanswered&lt;/span&gt;&lt;span class=&#34;status-icon&#34; aria-hidden=&#34;true&#34;/&gt; &lt;/span&gt; &lt;/div&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;solution-span&#34;&gt; &lt;span id=&#34;solution_29f1bfc3b77a4a89aee8fe149805bc98_solution_1&#34;/&gt; &lt;/div&gt;&lt;/div&gt; &lt;div class=&#34;action&#34;&gt; &lt;input type=&#34;hidden&#34; name=&#34;problem_id&#34; value=&#34;2e&#34; /&gt; &lt;div class=&#34;submit-attempt-container&#34;&gt; &lt;button type=&#34;button&#34; class=&#34;submit btn-brand&#34; data-submitting=&#34;Submitting&#34; data-value=&#34;Submit&#34; data-should-enable-submit-button=&#34;True&#34; aria-describedby=&#34;submission_feedback_29f1bfc3b77a4a89aee8fe149805bc98&#34; &gt; &lt;span class=&#34;submit-label&#34;&gt;Submit&lt;/span&gt; &lt;/button&gt; &lt;div class=&#34;submission-feedback&#34; id=&#34;submission_feedback_29f1bfc3b77a4a89aee8fe149805bc98&#34;&gt; &lt;span class=&#34;sr&#34;&gt;Some problems have options such as save, reset, hints, or show answer. 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