{"id":300205,"date":"2024-02-07T10:40:01","date_gmt":"2024-02-07T09:40:01","guid":{"rendered":"https:\/\/climatescience.press\/?p=300205"},"modified":"2024-02-07T10:40:04","modified_gmt":"2024-02-07T09:40:04","slug":"what-period-of-warming-best-correlates-with-climate-sensitivity","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=300205","title":{"rendered":"What Period of Warming Best Correlates with Climate Sensitivity?"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

From Roy Spencer, PhD.<\/a><\/p>\n\n\n\n

February 6th, 2024 by Roy W. Spencer, Ph. D.<\/small><\/p>\n\n\n\n

When computing temperature trends in the context of \u201cglobal warming\u201d we must choose a region (U.S.? global? etc.) and a time period (the last 10 years? 50 years? 100 years?) and a season (summer? winter? annual?). Obviously, we will obtain different temperature trends depending upon our choices. But what significance do these choices have in the context of global warming?<\/p>\n\n\n\n

Obviously, if we pick the most recent 10 years, such a short period can have a trend heavily influenced by an El Nino at the beginning and a La Nina at the end (thus depressing the trend) \u2014 or vice versa<\/em>.<\/p>\n\n\n\n

Alternatively, if we go too far back in time (say, before the mid-20th Century), increasing CO2 in the atmosphere cannot have much of an impact on the temperatures before that time. Inclusion of data too far back will just mute the signal we are looking for.<\/p>\n\n\n\n

One way to investigate this problem is to look at climate model output across many models to see how their warming trends compare to those models\u2019 diagnosed equilibrium climate sensitivities (ECS). I realize climate models have their own problems, but at least they generate internal variability somewhat like the real world, for instance with El Ninos and La Ninas scattered throughout their time simulations.<\/p>\n\n\n\n

I\u2019ve investigated this for 34 CMIP6 models having data available at the KNMI Climate Explorer website which also have published ECS values. The following plot shows the correlation between the 34 models\u2019 ECS and their temperature trends through 2023, but with different starting years.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

The peak correlation occurs around 1945, which is when CO2 emissions began to increase substantially, after World War II. But there is a reason why the correlations start to fall off after that date.<\/p>\n\n\n\n

The CMIP6 Climate Models Have Widely Differing Aerosol Forcings<\/strong><\/p>\n\n\n\n

The following plot (annotated by me, source publication\u00a0here<\/a>) shows that after WWII the various CMIP6 models have increasingly different amounts of aerosol forcings causing various amounts of cooling.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

If those models had not differed so much in their aerosol forcing, one could presumable have picked a later starting date than 1945 for meaningful temperature trend computation. Note the differences remain large even by 2015, which is reaching the point of not being useful anyway for trend computations through 2023.<\/p>\n\n\n\n

So, what period would provide the \u201cbest\u201d length of time to evaluate global warming claims? At this point, I honestly do not know.<\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

One way to investigate this problem is to look at climate model output across many models to see how their warming trends compare to those models\u2019 diagnosed equilibrium climate sensitivities (ECS). I realize climate models have their own problems, but at least they generate internal variability somewhat like the real world, for instance with El Ninos and La Ninas scattered throughout their time simulations.<\/p>\n","protected":false},"author":121246920,"featured_media":300210,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_crdt_document":"","advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"One way to investigate this problem is to look at climate model output across many models to see how their warming trends compare to those models\u2019 diagnosed equilibrium climate sensitivities (ECS). I realize climate models have their own problems, but at ","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[1],"tags":[691818698,691818076,691826785,691818087,691826784],"class_list":{"0":"post-300205","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","6":"hentry","7":"category-uncategorized","8":"tag-cmip6-models","9":"tag-co2","10":"tag-equilibrium-climate-sensitivities-ecs","11":"tag-global-warming","12":"tag-period-of-warming","14":"fallback-thumbnail"},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0Screenshot-2024-02-07-103854.png?fit=1198%2C784&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paxLW1-1g61","jetpack-related-posts":[{"id":299670,"url":"https:\/\/climatescience.press\/?p=299670","url_meta":{"origin":300205,"position":0},"title":"U.S.A. Temperature Trends, 1979-2023: Models vs. Observations","author":"uwe.roland.gross","date":"04\/02\/2024","format":false,"excerpt":"For the summer season, there are 26 models exhibiting warmer trends than the observations, and only 1 model with a weaker warming trend. The satellite tropospheric temperature trend is weakest of all.","rel":"","context":"In \"CMIP6 climate models\"","block_context":{"text":"CMIP6 climate models","link":"https:\/\/climatescience.press\/?tag=cmip6-climate-models"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0-Landscape.jpeg?fit=1200%2C801&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0-Landscape.jpeg?fit=1200%2C801&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0-Landscape.jpeg?fit=1200%2C801&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0-Landscape.jpeg?fit=1200%2C801&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0-Landscape.jpeg?fit=1200%2C801&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":235147,"url":"https:\/\/climatescience.press\/?p=235147","url_meta":{"origin":300205,"position":1},"title":"Climate Sensitivity from 1970-2021 Warming Estimates","author":"uwe.roland.gross","date":"19\/12\/2022","format":false,"excerpt":"Given the various estimates of surface and sub-surface warming over the last 50 years, what do they suggest for the sensitivity of the climate system to a doubling of atmospheric CO2?","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/image-607.png?fit=1200%2C737&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/image-607.png?fit=1200%2C737&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/image-607.png?fit=1200%2C737&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/image-607.png?fit=1200%2C737&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/12\/image-607.png?fit=1200%2C737&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":281157,"url":"https:\/\/climatescience.press\/?p=281157","url_meta":{"origin":300205,"position":2},"title":"Climate model provides data-driven answer to major goal of climate research","author":"uwe.roland.gross","date":"29\/09\/2023","format":false,"excerpt":"UAH\u2019s Dr. John Christy reviews results from the one-dimensional climate model Dr. Roy W. Spencer developed. Credit: Liz Junod From Phys.org by Dr. Roy W. Spencer,\u00a0University of Alabama in Huntsville A\u00a0new research study\u00a0from The University of Alabama in Huntsville, a part of the University of Alabama System, addresses a central\u2026","rel":"","context":"In \"CO2\"","block_context":{"text":"CO2","link":"https:\/\/climatescience.press\/?tag=co2"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00climate-model-provides.jpg?fit=1200%2C675&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00climate-model-provides.jpg?fit=1200%2C675&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00climate-model-provides.jpg?fit=1200%2C675&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00climate-model-provides.jpg?fit=1200%2C675&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/00climate-model-provides.jpg?fit=1200%2C675&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":301114,"url":"https:\/\/climatescience.press\/?p=301114","url_meta":{"origin":300205,"position":3},"title":"Proof that the Spencer & Christy Method of Plotting Temperature Time Series is Best","author":"uwe.roland.gross","date":"10\/02\/2024","format":false,"excerpt":"The goal here is to plot multiple temperature time series on a single graph in such a way the their different rates of long-term warming (usually measured by linear warming trends) are best reflected by their placement on the graph, without hiding those differences.","rel":"","context":"In \"climate model data\"","block_context":{"text":"climate model data","link":"https:\/\/climatescience.press\/?tag=climate-model-data"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0Screenshot-2024-02-10-205706.png?fit=1128%2C897&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0Screenshot-2024-02-10-205706.png?fit=1128%2C897&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0Screenshot-2024-02-10-205706.png?fit=1128%2C897&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0Screenshot-2024-02-10-205706.png?fit=1128%2C897&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/02\/0Screenshot-2024-02-10-205706.png?fit=1128%2C897&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":299201,"url":"https:\/\/climatescience.press\/?p=299201","url_meta":{"origin":300205,"position":4},"title":"Spencer vs. Schmidt: My Response to RealClimate.org Criticisms","author":"uwe.roland.gross","date":"31\/01\/2024","format":false,"excerpt":"What follows is a response to Gavin Schmidt\u2019s blog post at RealClimate.org entitled\u00a0Spencer\u2019s Shenanigans\u00a0in which he takes issue with my claims in\u00a0Global Warming: Observations vs. Climate Models. As I read through his criticism, he seems to be trying too hard to refute my claims while using weak (and even non-existent)\u2026","rel":"","context":"In \"Climate change\"","block_context":{"text":"Climate change","link":"https:\/\/climatescience.press\/?tag=climate-change"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/07\/0climatemodels-average-vs-satellite.png?fit=1200%2C889&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/07\/0climatemodels-average-vs-satellite.png?fit=1200%2C889&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/07\/0climatemodels-average-vs-satellite.png?fit=1200%2C889&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/07\/0climatemodels-average-vs-satellite.png?fit=1200%2C889&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/07\/0climatemodels-average-vs-satellite.png?fit=1200%2C889&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":441135,"url":"https:\/\/climatescience.press\/?p=441135","url_meta":{"origin":300205,"position":5},"title":"Why Climate Models Get Ocean Warming Patterns Wrong: They Exaggerate Greenhouse Gas Effects on the Hemispheres","author":"uwe.roland.gross","date":"24\/04\/2026","format":false,"excerpt":"Climate models and ocean observations diverge primarily on the pattern of hemispheric ocean warming\u2014specifically, the interhemispheric thermal contrast (IHTC), or the difference in average sea surface temperature (SST) between the Northern and Southern Hemispheres. This is not a failure of global temperature trends (models and observations align closely on overall\u2026","rel":"","context":"In \"anthropogenic aerosols\"","block_context":{"text":"anthropogenic aerosols","link":"https:\/\/climatescience.press\/?tag=anthropogenic-aerosols"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/04\/0-Why-Climate-Models-Get-Ocean-Warming-Patterns-Wrong-They-Exaggerate-Greenhouse-Gas-Effects-on-the-Hemispheres.jpg?fit=1168%2C784&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/04\/0-Why-Climate-Models-Get-Ocean-Warming-Patterns-Wrong-They-Exaggerate-Greenhouse-Gas-Effects-on-the-Hemispheres.jpg?fit=1168%2C784&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/04\/0-Why-Climate-Models-Get-Ocean-Warming-Patterns-Wrong-They-Exaggerate-Greenhouse-Gas-Effects-on-the-Hemispheres.jpg?fit=1168%2C784&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/04\/0-Why-Climate-Models-Get-Ocean-Warming-Patterns-Wrong-They-Exaggerate-Greenhouse-Gas-Effects-on-the-Hemispheres.jpg?fit=1168%2C784&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/04\/0-Why-Climate-Models-Get-Ocean-Warming-Patterns-Wrong-They-Exaggerate-Greenhouse-Gas-Effects-on-the-Hemispheres.jpg?fit=1168%2C784&ssl=1&resize=1050%2C600 3x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/300205","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/users\/121246920"}],"replies":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=300205"}],"version-history":[{"count":3,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/300205\/revisions"}],"predecessor-version":[{"id":300211,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/300205\/revisions\/300211"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/media\/300210"}],"wp:attachment":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=300205"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=300205"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=300205"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}