{"id":820,"date":"2019-09-23T15:45:55","date_gmt":"2019-09-23T22:45:55","guid":{"rendered":"https:\/\/c21-wp.phas.ubc.ca\/index.php\/co2e"},"modified":"2019-09-23T16:24:33","modified_gmt":"2019-09-23T23:24:33","slug":"co2e","status":"publish","type":"article","link":"https:\/\/c21.phas.ubc.ca\/article\/co2e\/","title":{"rendered":"CO2e"},"content":{"rendered":"<p><strong>\u00a0The &#8220;e&#8221; means &#8220;equivalent&#8221;.\u00a0<\/strong><\/p>\n<ul>\n<li>&#8220;CO<sub>2<\/sub>e&#8221; is a concept that allows us to express the impact of any\u00a0greenhouse gas (GHG) by comparing it to some amount of\u00a0CO<sub>2<\/sub>.<\/li>\n<li>There are two common ways of doing this.<\/li>\n<\/ul>\n<p>1. &#8220;CO<sub>2<\/sub>e&#8221; is the mass of CO<sub>2\u00a0<\/sub>that would have an equal Global Warming Potential (GWP) to the mass of whatever greenhouse gas (GHG) is in question, over a defined period of time.<\/p>\n<ul>\n<li>Generally uses the units of tonnes.<\/li>\n<li>GWP is a measure of the effect of a greenhouse gas on the global mean temperature.\n<ul>\n<li>It is calculated over fixed time interval, usually 100 years. This is because some GHGs have a finite lifetime in the atmosphere.<\/li>\n<li>For example methane (CH<sub>4<\/sub>) is reckoned to have about 25 times the impact on the climate over 100 years as the same mass of\u00a0CO<sub>2<\/sub>, so the addition of one tonne of\u00a0CH<sub>4\u00a0<\/sub>\u00a0to the atmosphere would add 25 tonnes to the total\u00a0CO<sub>2<\/sub>e.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>2.\u00a0\u00a0&#8220;CO<sub>2<\/sub>e&#8221; is the\u00a0concentration of CO<sub>2<\/sub> in the atmosphere that would cause the same temperature impact on the climate as would be caused by the GHG in question.<\/p>\n<ul>\n<li>Generally uses the units of parts per million (ppm), calculated by <em>volume<\/em> rather than mass (sometimes called ppmv to be explicit).<\/li>\n<li>For example, the current concentration of CO<sub>2<\/sub> in the atmosphere is 390 ppm (2012), but other GHGs push this up to a CO<sub>2<\/sub>e of 430 ppm, i.e. the greenhouse effect is as strong as if the only GHG in the atmosphere was CO<sub>2<\/sub> at 430 ppm concentration.<\/li>\n<\/ul>\n<p class=\"rtecenter\">\n<div id=\"attachment_2161\" style=\"width: 235px\" class=\"wp-caption aligncenter\"><img aria-describedby=\"caption-attachment-2161\" decoding=\"async\" class=\"wp-image-2161 size-medium\" src=\"https:\/\/c21-wp.phas.ubc.ca\/wp-content\/uploads\/2012\/03\/IMG_1514-225x300.jpg\" alt=\"\" width=\"225\" height=\"300\" srcset=\"https:\/\/c21.phas.ubc.ca\/wp-content\/uploads\/2012\/03\/IMG_1514-225x300.jpg 225w, https:\/\/c21.phas.ubc.ca\/wp-content\/uploads\/2012\/03\/IMG_1514-768x1024.jpg 768w\" sizes=\"(max-width: 225px) 100vw, 225px\" \/><p id=\"caption-attachment-2161\" class=\"wp-caption-text\">CH2O\u00a0in one end, CO2e out the other.<\/p><\/div>\n<p>&nbsp;<\/p>\n<p><strong>Partially Updated 2019-09-23<\/strong><\/p>\n","protected":false},"author":6,"featured_media":2161,"template":"","tags":[81,136,137],"date_post_made_public":"0000-00-00","post_authored_by":"","hook":"What does the \"e\" mean?","big_ideas":"<ul>\r\n \t<li>Quantifying the effects of atmospheric components on the Earth's climate<\/li>\r\n<\/ul>","thumbnail_for_post":"<img class=\"size-thumbnail wp-image-2161 alignleft\" src=\"https:\/\/c21-wp.phas.ubc.ca\/wp-content\/uploads\/2012\/03\/IMG_1514-150x150.jpg\" alt=\"\" width=\"150\" height=\"150\" \/>","series":false,"number_in_series":"0","supporting_classroom_materials":false,"supporting_experiment":false,"related_articles":false,"related_experiments":false,"related_classroom_materials":false,"_links":{"self":[{"href":"https:\/\/c21.phas.ubc.ca\/wp-json\/wp\/v2\/article\/820"}],"collection":[{"href":"https:\/\/c21.phas.ubc.ca\/wp-json\/wp\/v2\/article"}],"about":[{"href":"https:\/\/c21.phas.ubc.ca\/wp-json\/wp\/v2\/types\/article"}],"author":[{"embeddable":true,"href":"https:\/\/c21.phas.ubc.ca\/wp-json\/wp\/v2\/users\/6"}],"version-history":[{"count":4,"href":"https:\/\/c21.phas.ubc.ca\/wp-json\/wp\/v2\/article\/820\/revisions"}],"predecessor-version":[{"id":2370,"href":"https:\/\/c21.phas.ubc.ca\/wp-json\/wp\/v2\/article\/820\/revisions\/2370"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c21.phas.ubc.ca\/wp-json\/wp\/v2\/media\/2161"}],"wp:attachment":[{"href":"https:\/\/c21.phas.ubc.ca\/wp-json\/wp\/v2\/media?parent=820"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c21.phas.ubc.ca\/wp-json\/wp\/v2\/tags?post=820"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}