The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉
Main Topic: Some Climate Models Are Underestimating Global Warming
Dear Diary. The proof will be in the warm pudding that all of us will experience going into the mid 21st century years, but apparently some climate models with low sensitivity to greenhouse gases do not align with satellite measurements according to a new study. Essentially this means that there has been an underestimation of global warming that has already taken place by some models. I suspect that an ensemble of all models is used to track and forecast global warming, but looking at the findings of the study, this gives me a nervous pause. We are perilously close to getting a climate that our society just can’t cope with.
As I described on Sunday, the eastern half of the U.S. will get a taste of what typical summers will be like in the future when a mega heat dome sets up over the area. We will see how hot and how long Heatwave Schell lasts starting this weekend.
In any case, here is a summary of findings from that new ominous study suggesting that global warming is being underestimated by some of our models:
June 12, 2025
Climate models with low sensitivity to greenhouse gases do not align with satellite measurements
by Centre for International Climate and Environmental Research
edited by Lisa Lock, reviewed by Robert Egan
SW EEI per degree warming trends versus LW EEI trends per degree warming in CMIP6 models and CERES satellite data. Colors show climate sensitivity of each CMIP6 model. Credit: Science (2025). DOI: 10.1126/science.adt0647. https://www.science.org/doi/10.1126/science.adt0647
Climate models that give a low warming from increases in greenhouse gases do not match satellite measurements. Future warming will likely be worse than thought unless society acts, according to a new study published in Science.
Increases in greenhouse gases, especially CO₂, cause Earth to warm. Although the physics of global warming is well understood, scientists have been uncertain about exactly how much warming to expect from increases in CO₂ and other greenhouse gases. The largest source of this uncertainty is how clouds will respond as the climate warms—clouds are complex and can respond to warming in complex ways which likely amplify the warming caused by greenhouse gases, but by an uncertain amount.
In a stable climate, Earth emits as much energy into space as it receives from the sun. However, as greenhouse gas concentration increases, this balance is changing. Satellite measurements since 2001 clearly show significant changes in both solar radiation absorbed by Earth and the outgoing thermal radiation from Earth.
Climate models are an important tool for understanding how the atmosphere, including clouds, respond to the warming from greenhouse gases. The latest generation of climate models still have a relatively large range in the amount of global warming we can expect from the same increase in greenhouse gas concentration.
The new study led by the Center for International Climate Research (CICERO), with co-authors from NASA Langley Research Center and Priestley Center for Climate Futures (University of Leeds), shows that climate models that give a low warming from increases in greenhouse gases do not match satellite measurements. This means that models with a stronger warming response to greenhouse gas increases are more realistic.
In the paper now published in Science, the authors highlighted that this in turn will increase estimates of global warming this century if the world continues along its current emission trajectory. Future warming will likely be worse than thought unless society acts.
“We therefore need to cut greenhouse gas emissions even further to have a chance of keeping global warming below 2 degrees,” Gunnar Myhre, research director at CICERO and lead author of the study, said.
Climate sensitivity
The most common way to assess how much warming we can expect from a given increase in greenhouse gases is to estimate the temperature increase from a doubling of atmospheric CO₂ concentration. Earth warms in direct response to the CO2 increase, but this warming in turn drives other changes, such as increases in atmospheric water vapor, snow and ice melting and cloud changes. These changes are termed climate feedbacks and they all add to the initial warming. Cloud changes, in particular, contribute significantly to the uncertainty in how sensitive the climate system is to greenhouse gases.
The latest UN climate report (IPCC, 2021) estimates a most likely climate sensitivity of 3°C. It is very likely between 2 and 5°C, and likely between 2.5 and 4°C. These estimates are based on theoretical understanding, reconstructions of past climate conditions (such as ice ages and warm periods), and observations since 1850.
Science study
The CERES satellite measures Earth’s energy imbalance—specifically, how much solar radiation is absorbed compared to how much heat (longwave) radiation is emitted back into space. The data show a significant increase in absorbed solar radiation, partly due to reduced snow and ice cover, but also because of changes to clouds. At the same time, Earth is emitting more heat, driven by rising surface temperatures.
The satellite measurements have been compared with results from 37 climate models. The study shows a clear connection between climate sensitivity in the models and the ratio between increased absorbed solar radiation and increased heat radiation from Earth. Climate models with low climate sensitivity show small changes in the energy imbalance in the individual contributions from absorbed solar radiation and increased terrestrial radiation from Earth, and are less able to reproduce what is measured from satellite data.
This indicates that a climate sensitivity in the lower half of the IPCC range is less likely and a higher climate sensitivity is more likely. This would suggest that weaker degrees of global warming response to greenhouse gases can be ruled out, and that estimates of stronger future warming, for a given change in greenhouse gases, become more likely.
Models with climate sensitivity lower than 2.9°C show significantly smaller increases in absorbed solar radiation than what is measured by CERES. For models with climate sensitivity lower than 2.5°C, it is not possible to replicate the satellite observations—even when taking into account the possibility that the models underestimate the effect of reduced emissions of polluting particles. This demonstrates how important satellite data, particularly CERES data, are for monitoring and understanding of current climate change.
More information: Gunnar Myhre, Observed trend in Earth energy imbalance may provide a constraint for low climate sensitivity models, Science (2025). DOI: 10.1126/science.adt0647. www.science.org/doi/10.1126/science.adt0647
Journal information: Science
Provided by Centre for International Climate and Environmental Research
Explore further
Clouds have a surprising effect on surface warming, climate researchers find
Here are more “ETs” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks, as well as any extreme precipitation reports:
Here is More Climate News from Thursday:
(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)