{"id":54396,"date":"2020-07-26T07:02:12","date_gmt":"2020-07-26T12:02:12","guid":{"rendered":"https:\/\/olduvai.ca\/?p=54396"},"modified":"2020-07-26T07:02:16","modified_gmt":"2020-07-26T12:02:16","slug":"guest-post-why-low-end-climate-sensitivity-can-now-be-ruled-out","status":"publish","type":"post","link":"https:\/\/olduvai.ca\/?p=54396","title":{"rendered":"Guest post: Why low-end \u2018climate sensitivity\u2019 can now be ruled out"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\"><a href=\"https:\/\/www.carbonbrief.org\/guest-post-why-low-end-climate-sensitivity-can-now-be-ruled-out\">Guest post: Why low-end \u2018climate sensitivity\u2019 can now be ruled out<\/a><\/h3>\n\n\n\n<p>After four years of labour and detailed discussions by an international team of scientists, we are able to quantify better than ever before how the world\u2019s surface temperature responds to increasing CO2 levels.&nbsp;<\/p>\n\n\n\n<p>Our findings, published in&nbsp;<a href=\"https:\/\/doi.org\/10.1029\/2019RG000678\" target=\"_blank\" rel=\"noreferrer noopener\">Reviews of Geophysics<\/a>, narrow the likely range in \u201c<a href=\"https:\/\/www.carbonbrief.org\/explainer-how-scientists-estimate-climate-sensitivity\">equilibrium climate sensitivity<\/a>\u201d (ECS) \u2013 a measure of how much the world can be expected to warm for a doubling of CO2 above&nbsp;<a href=\"https:\/\/www.carbonbrief.org\/challenge-defining-pre-industrial-era\">pre-industrial levels<\/a>.<\/p>\n\n\n\n<p>Constraining ECS has remained a holy grail in climate science ever since US meteorologist&nbsp;<a href=\"https:\/\/en.wikipedia.org\/wiki\/Jule_Gregory_Charney\" target=\"_blank\" rel=\"noreferrer noopener\">Jules Charney<\/a>&nbsp;suggested a possible range of 1.5C to 4.5C in his&nbsp;<a href=\"https:\/\/www.nap.edu\/catalog\/12181\/carbon-dioxide-and-climate-a-scientific-assessment\" target=\"_blank\" rel=\"noreferrer noopener\">1979 report<\/a>. His estimate was largely based on the&nbsp;<a href=\"https:\/\/www.carbonbrief.org\/timeline-history-climate-modelling\">world\u2019s first two global climate models<\/a>, which gave different estimates of 2C and 4C when they performed a simple experiment where atmospheric CO2 levels were doubled.<\/p>\n\n\n\n<p>Since then, despite more than 40 years of research, much improved understanding of atmospheric processes, as well as many more detailed observations, this range has stubbornly persisted.&nbsp;<\/p>\n\n\n\n<p>Now, bringing together evidence from observed warming, Earth\u2019s distant past and climate models, as well as advances in our scientific understanding of the climate, our findings suggest that the range of ECS is likely to be between 2.6C and 4.1C.&nbsp;<\/p>\n\n\n\n<p>This narrowed range indicates that human society will not be able to rely on a low sensitivity to give us more time to tackle climate change. But the silver lining to this cloud is that our findings also suggest that very high ECS estimates are unlikely.\u00a0<\/p>\n\n\n\n<p><strong>Stubbornly wide range<\/strong><\/p>\n\n\n\n<p>How sensitive the Earth\u2019s climate is to increasing atmospheric CO2 is a fundamental question for climate science. It essentially dictates how much the Earth\u2019s surface will warm in response to human-caused CO2 emissions.<\/p>\n\n\n\n<p>\u2026click on the above link to read the rest of the article\u2026<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Guest post: Why low-end \u2018climate sensitivity\u2019 can now be ruled out After four years of labour and detailed discussions by an international team of scientists, we are able to quantify better than ever before how the world\u2019s surface temperature responds to increasing CO2 levels.&nbsp; Our findings, published in&nbsp;Reviews of Geophysics, narrow the likely range in [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[4],"tags":[10797,141,30093,30092,30094,30091,30095],"class_list":["post-54396","post","type-post","status-publish","format-standard","hentry","category-environment","tag-carbon-brief","tag-climate-change","tag-dr-zeke-hausfather","tag-prof-gabi-hegerl","tag-prof-kyle-armour","tag-prof-piers-forster","tag-prof-steven-sherwood"],"_links":{"self":[{"href":"https:\/\/olduvai.ca\/index.php?rest_route=\/wp\/v2\/posts\/54396","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/olduvai.ca\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/olduvai.ca\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/olduvai.ca\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/olduvai.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=54396"}],"version-history":[{"count":1,"href":"https:\/\/olduvai.ca\/index.php?rest_route=\/wp\/v2\/posts\/54396\/revisions"}],"predecessor-version":[{"id":54397,"href":"https:\/\/olduvai.ca\/index.php?rest_route=\/wp\/v2\/posts\/54396\/revisions\/54397"}],"wp:attachment":[{"href":"https:\/\/olduvai.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=54396"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/olduvai.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=54396"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/olduvai.ca\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=54396"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}