{"id":421404,"date":"2026-01-15T10:11:33","date_gmt":"2026-01-15T09:11:33","guid":{"rendered":"https:\/\/climatescience.press\/?p=421404"},"modified":"2026-01-15T10:11:35","modified_gmt":"2026-01-15T09:11:35","slug":"tropical-tropospheric-temperature-trends-1979-2025-the-epic-climate-model-failure-continues","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=421404","title":{"rendered":"Tropical Tropospheric Temperature Trends, 1979-2025: The Epic Climate Model Failure Continues"},"content":{"rendered":"\n
\"Line<\/figure>\n\n\n\n

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

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

January 13th, 2026 by Roy W. Spencer, Ph. D.<\/small><\/p>\n\n\n\n

As a follow-on to my recent post<\/a> regarding global surface air temperature trends (1979-2025) and how they compare to climate models, this is an update on a similar comparison for tropical tropospheric temperature trends, courtesy of tabulations made by John Christy. It also represents an update to my popular \u201cepic fail\u201d blog post<\/a> from 2013.<\/p>\n\n\n\n

As most of you know, climate models suggest that the strongest warming response the climate system has to increasing anthropogenic greenhouse gas (GHG) emissions (mainly CO2 from fossil fuel burning) is in the tropical upper troposphere. This produces the model-anticipated \u201ctropical hotspot\u201d.<\/p>\n\n\n\n

While the deep oceans represent the largest reservoir of heat energy storage in the climate system during warming, that signal is exceedingly small (hundredths of a degree C per decade) and so its uncertainty is rather large from an observational standpoint. In contrast, the tropical upper troposphere has the largest temperature response in climate models (up to 0.5 deg. C per decade).<\/p>\n\n\n\n

This shown in the following plot of the decadal temperature trends from 39 climate models (red bars) compared to observations gathered from radiosondes (weather balloons); satellites; and global data reanalyses (which use all kinds of available meteorological data).<\/p>\n\n\n

\n
\"Bar<\/figure>\n<\/div>\n\n\n

The sonde trend bar in the above plot (green) is the average of 3 datasets (radiosonde coverage of the tropics is very sparse); the reanalysis trend (black) is from 2 datasets, and the satellite trend (blue) is the average of 3 datasets. Out of all types of observational data, only the satellites provide complete coverage of the tropics.<\/p>\n\n\n\n

Amazingly, all 39 climate models exhibit larger warming trends than all three classes of observational data.<\/p>\n\n\n\n

Time Series, 1979-2025<\/strong><\/p>\n\n\n\n

If we compare the average model warming to the observations in individual years, we get the following time series (note that complete reanalysis data for 2025 are not yet available); color coding remains the same as in the previous plot:<\/p>\n\n\n

\n
\"Graph<\/figure>\n<\/div>\n\n\n

The unusually warm year of 2024 really stands out (likely due to a decrease in cloud cover letting in more sunlight), but in 2025 the satellites and radiosondes show a \u201creturn to trend\u201d. Of course, what happens in the future is anyone\u2019s guess.<\/p>\n\n\n\n

\u201cSo What? No One Lives In the Tropical Troposphere\u201d<\/strong><\/p>\n\n\n\n

What is going on that might explain these discrepancies, not only between the models and the observations, but even between the various models themselves? And why should we care, since no one lives up in the tropical troposphere, anyway?<\/p>\n\n\n\n

Well, the same argument can be made about the deep oceans (no one lives there), yet they are pointed to by many climate researchers as the most important \u201cbarometer\u201d of the positive global energy imbalance of the climate system caused by increasing GHGs (and maybe by natural processes\u2026 who knows?).<\/p>\n\n\n\n

The excessive warming of the tropical troposphere is no doubt related to inadequacies in how the models handle convective overturning in the tropics, that is, organized thunderstorm activity that transports heat from the surface upward. That \u201cdeep moist convection\u201d redistributes not only heat energy, but clouds and water vapor, both of which have profound impacts on tropical tropospheric temperature. While moistening of the lowest layer of the troposphere in response to warming no doubt contributes to positive water vapor feedback, precipitation microphysics governs how much water vapor resides in the rest of the troposphere, and as we demonstrated<\/a> almost 30 years ago, that leads to large uncertainties in total water vapor feedback.<\/p>\n\n\n\n

My personal opinion has always been that the lack of tropical warming is because positive water vapor feedback, the primary positive feedback that amplifies warming in climate models, is too strong. Climate models actually support this interpretation because it has long been known that those models with the strongest \u201chotspot\u201d in the upper troposphere tend to have the largest positive water vapor feedback.<\/p>\n\n\n\n

Will Climate Models Ever Be \u201cFixed\u201d?<\/strong><\/p>\n\n\n\n

I find it ironic that climate models are claimed to be based upon fundamental \u201cphysical principles\u201d. If that were true, then all models would have the same climate sensitivity to increasing GHGs.<\/p>\n\n\n\n

But they don\u2019t.<\/p>\n\n\n\n

Climate models range over a factor of three in climate sensitivity, a disparity that has remained for over 30 years of the climate modeling enterprise. And the main reason for that disparity is inter-model differences in the moist convective processes (clouds and water vapor) which cause positive feedbacks in the models.<\/p>\n\n\n\n

Maybe if the modelers figured out why their handling of moist convection is flawed, models would then produce warming more in line with observations, and more in line with each other.<\/p>\n\n\n\n

Much of global warming alarmism arises from scientific publications biased toward (1) the models that produce the most warming, and (2) the excessive GHG increases (\u201cSSP scenarios<\/a>\u201c) they assume for the most dire climate change projections. Those scenarios are now known to be excessive compared to observed rates of global GHG emissions (and to the reviewer of our DOE report who said this conclusion was in error because I didn\u2019t account for land use changes, no, I removed land use changes from the SSP scenarios\u2026 it was an apples-to-apples comparison).<\/p>\n\n\n\n

Finally, I don\u2019t want to make it sound like I\u2019m against climate modeling. I am definitely not. I just think the models, as a tool for energy policy guidance, have been misused.<\/p>\n\n\n\n

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

As a follow-on to my\u00a0recent post\u00a0regarding global surface air temperature trends (1979-2025) and how they compare to climate models, this is an update on a similar comparison for tropical tropospheric temperature trends, courtesy of tabulations made by John Christy. It also represents an update to my popular\u00a0\u201cepic fail\u201d blog post\u00a0from 2013.<\/p>\n","protected":false},"author":121246920,"featured_media":421411,"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":"Explore the ongoing discrepancies between climate models and observed tropical tropospheric temperature trends from 1979 to 2025. Learn more!","jetpack_seo_html_title":"Tropical Tropospheric Temperature Trends: Model vs. Reality","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":"","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":true,"token":"eyJpbWciOiJodHRwczpcL1wvY2xpbWF0ZS1zY2llbmNlLnByZXNzXC93cC1jb250ZW50XC91cGxvYWRzXC8yMDI2XC8wMVwvMFNjcmVlbnNob3QtMjAyNi0wMS0xNS0xMDEwMDAtMTAyNHg1MTMucG5nIiwidHh0IjoiVHJvcGljYWwgVHJvcG9zcGhlcmljIFRlbXBlcmF0dXJlIFRyZW5kcywgMTk3OS0yMDI1OiBUaGUgRXBpYyBDbGltYXRlIE1vZGVsIEZhaWx1cmUgQ29udGludWVzIiwidGVtcGxhdGUiOiJoaWdod2F5IiwiZm9udCI6IiIsImJsb2dfaWQiOjE1NTgxMjQ0OX0.EPzgKannPAfoBi0cvwPAXQzJdEVNZYkRem2z9REsDWgMQ"},"version":2},"jetpack_post_was_ever_published":false},"categories":[1],"tags":[691840725,691829997,691818153,691840726,691820010,691840724],"class_list":{"0":"post-421404","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","6":"hentry","7":"category-uncategorized","8":"tag-anthropogenic-greenhouse-gas-ghg","9":"tag-carbon-dioxide-co","10":"tag-climate-models","11":"tag-radiosondes-weather-balloons","12":"tag-satellites","13":"tag-surface-air-temperature-trends-1979-2025","15":"fallback-thumbnail"},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0Screenshot-2026-01-15-101000.png?fit=1496%2C750&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paxLW1-1LCQ","jetpack-related-posts":[{"id":420929,"url":"https:\/\/climatescience.press\/?p=420929","url_meta":{"origin":421404,"position":0},"title":"Surface Air Temperature Trends, Climate Models vs Observations, 1979-2025","author":"uwe.roland.gross","date":"11\/01\/2026","format":false,"excerpt":"This is just a short update regarding how global surface air temperature (Tsfc) trends are tracking 34 CMIP6 climate models through 2025. The following plot shows the Tsfc trends, 1979-2025, ranked from the warmest to the coolest.","rel":"","context":"In \"(Tsfc) trends\"","block_context":{"text":"(Tsfc) trends","link":"https:\/\/climatescience.press\/?tag=tsfc-trends"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0Ranked-CMIP6-vs-Obs-Tsfc-warming-trends-1979-2025-1536x1283-1.jpg?fit=1200%2C1002&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0Ranked-CMIP6-vs-Obs-Tsfc-warming-trends-1979-2025-1536x1283-1.jpg?fit=1200%2C1002&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0Ranked-CMIP6-vs-Obs-Tsfc-warming-trends-1979-2025-1536x1283-1.jpg?fit=1200%2C1002&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0Ranked-CMIP6-vs-Obs-Tsfc-warming-trends-1979-2025-1536x1283-1.jpg?fit=1200%2C1002&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0Ranked-CMIP6-vs-Obs-Tsfc-warming-trends-1979-2025-1536x1283-1.jpg?fit=1200%2C1002&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":299670,"url":"https:\/\/climatescience.press\/?p=299670","url_meta":{"origin":421404,"position":1},"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":420006,"url":"https:\/\/climatescience.press\/?p=420006","url_meta":{"origin":421404,"position":2},"title":"UAH v6.1 Global Temperature Update for December 2025: +0.30 deg. C","author":"uwe.roland.gross","date":"05\/01\/2026","format":false,"excerpt":"This monthly update from Dr. Roy Spencer and John Christy at the University of Alabama in Huntsville is typically released early in the following month (e.g., around January 3-5, 2026). If this is the official release, it suggests continued cooling into early 2026, potentially making 2025 one of the warmer\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0AQPbgOQc-dCL0fr-0SPEmknewXuFEw4f5EOLJRt6XArv5wdtdsot21dyqAyXEGkEvazEkTLYzodH3C5vYglpMYiZE9oUtMvpWUggbVfmndqrBV58PmQ6qR3VCgWbYbJj-1.jpeg?fit=1200%2C537&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0AQPbgOQc-dCL0fr-0SPEmknewXuFEw4f5EOLJRt6XArv5wdtdsot21dyqAyXEGkEvazEkTLYzodH3C5vYglpMYiZE9oUtMvpWUggbVfmndqrBV58PmQ6qR3VCgWbYbJj-1.jpeg?fit=1200%2C537&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0AQPbgOQc-dCL0fr-0SPEmknewXuFEw4f5EOLJRt6XArv5wdtdsot21dyqAyXEGkEvazEkTLYzodH3C5vYglpMYiZE9oUtMvpWUggbVfmndqrBV58PmQ6qR3VCgWbYbJj-1.jpeg?fit=1200%2C537&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0AQPbgOQc-dCL0fr-0SPEmknewXuFEw4f5EOLJRt6XArv5wdtdsot21dyqAyXEGkEvazEkTLYzodH3C5vYglpMYiZE9oUtMvpWUggbVfmndqrBV58PmQ6qR3VCgWbYbJj-1.jpeg?fit=1200%2C537&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/01\/0AQPbgOQc-dCL0fr-0SPEmknewXuFEw4f5EOLJRt6XArv5wdtdsot21dyqAyXEGkEvazEkTLYzodH3C5vYglpMYiZE9oUtMvpWUggbVfmndqrBV58PmQ6qR3VCgWbYbJj-1.jpeg?fit=1200%2C537&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":254196,"url":"https:\/\/climatescience.press\/?p=254196","url_meta":{"origin":421404,"position":3},"title":"40 years of expert failure: New NOAA STAR satellite temperatures only show half the warming that climate models do","author":"uwe.roland.gross","date":"22\/04\/2023","format":false,"excerpt":"An all new reanalysis of the STAR satellite data finds markedly lower temperature trends for the last 40 years. The big deal about this is that this third dataset suddenly supports the original UAH satellite data, not the other RSS system, and not the \u201csurface thermometers\u201d sitting near hot tarmacs\u2026","rel":"","context":"In \"climate modelers\"","block_context":{"text":"climate modelers","link":"https:\/\/climatescience.press\/?tag=climate-modelers"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/04\/00modelsvsdata.png?fit=1200%2C1080&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/04\/00modelsvsdata.png?fit=1200%2C1080&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/04\/00modelsvsdata.png?fit=1200%2C1080&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/04\/00modelsvsdata.png?fit=1200%2C1080&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/04\/00modelsvsdata.png?fit=1200%2C1080&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":437206,"url":"https:\/\/climatescience.press\/?p=437206","url_meta":{"origin":421404,"position":4},"title":"March 2026 Satellite Temperatures: Record Warmth in U.S., But Uneventful for the Northern Hemisphere","author":"uwe.roland.gross","date":"04\/04\/2026","format":false,"excerpt":"It is human nature to think the weather we experience has some sort of global significance. But look at NOAA\u2019s best estimate of March 2026 temperature departures from \u201cnormal\u201d (1991-2020 average) over North America (below). Yeah, the U.S. was unusually warm. But what about all the unusual chill over the\u2026","rel":"","context":"In \"Lower Troposphere\"","block_context":{"text":"Lower Troposphere","link":"https:\/\/climatescience.press\/?tag=lower-troposphere"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/04\/0-March-2026-Satellite-Temperature-Record-Warmth-in-U.S.-But-Uneventful-for-the-Northern-Hemisphere.jpg?fit=784%2C1168&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/04\/0-March-2026-Satellite-Temperature-Record-Warmth-in-U.S.-But-Uneventful-for-the-Northern-Hemisphere.jpg?fit=784%2C1168&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/04\/0-March-2026-Satellite-Temperature-Record-Warmth-in-U.S.-But-Uneventful-for-the-Northern-Hemisphere.jpg?fit=784%2C1168&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/04\/0-March-2026-Satellite-Temperature-Record-Warmth-in-U.S.-But-Uneventful-for-the-Northern-Hemisphere.jpg?fit=784%2C1168&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":332116,"url":"https:\/\/climatescience.press\/?p=332116","url_meta":{"origin":421404,"position":5},"title":"UAH Upper Tropospheric Temperatures Corroborate LT Temperature Trends","author":"uwe.roland.gross","date":"08\/06\/2024","format":false,"excerpt":"The recent record-setting UAH satellite-based temperatures of the lower troposphere can be compared to a different combination of satellite MSU\/AMSU channels which help to corroborate the temperature trends from our \u201clower tropospheric\u201d (LT) combination of channels.","rel":"","context":"In \"Lower Troposphere\"","block_context":{"text":"Lower Troposphere","link":"https:\/\/climatescience.press\/?tag=lower-troposphere"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0-troposphere.jpeg?fit=1200%2C674&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0-troposphere.jpeg?fit=1200%2C674&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0-troposphere.jpeg?fit=1200%2C674&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0-troposphere.jpeg?fit=1200%2C674&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0-troposphere.jpeg?fit=1200%2C674&ssl=1&resize=1050%2C600 3x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/421404","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=421404"}],"version-history":[{"count":4,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/421404\/revisions"}],"predecessor-version":[{"id":421413,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/421404\/revisions\/421413"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/media\/421411"}],"wp:attachment":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=421404"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=421404"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=421404"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}