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Climate change is accelerating, scientists find in ‘grim’ report
Posted on 17 September 2025 by dana1981
This is a re-post from Yale Climate Connections
he amount of heat trapped by climate-warming pollution in our atmosphere is continuing to increase, the planet’s sea levels are rising at an accelerating rate, and the Paris agreement’s ambitious 1.5°C target is on the verge of being breached, according to a recent report by the world’s top climate scientists.
“The news is grim,” said study co-author Zeke Hausfather, a former Yale Climate Connections contributor, on Bluesky.
A team of over 60 international scientists published the latest edition of an annual report updating key metrics that are used in reports of the Intergovernmental Panel on Climate Change, the leading international scientific authority on climate change.
Earth out of balance
Climate change is caused by variations in Earth’s energy balance – the difference between the planet’s incoming and outgoing energy. Nearly all incoming energy originates from the sun. The Earth absorbs that sunlight and sends it back out toward space in the form of infrared light, or heat. Greenhouse gases such as carbon dioxide absorb infrared light, and so increased levels in those gases trap more heat in the atmosphere, warming the planet’s surface and oceans.
The new report finds that as a result of this increasing greenhouse effect, Earth’s energy imbalance has been consistently rising every decade. In fact, the global imbalance has more than doubled just since the 1980s. And from 2020 to 2024, humans exacerbated the problem by adding about 200 billion more tons of carbon dioxide-equivalent greenhouse gases to the atmosphere.
This increase in trapped energy has continued to warm Earth’s surface temperatures. The new study estimated that at current rates, humans will burn enough fossil fuels and release enough climate pollution to commit the planet to over 1.5°C of global warming above preindustrial temperatures within about three more years, in 2028.
The most recent report from the Intergovernmental Panel on Climate Change, published in 2021, concluded that average temperatures had increased 1.09°C since the late 1800s. The new study updates this number to 1.24°C, driven largely by the record-shattering hot years of 2023 and 2024.
The paper also finds that global surface temperatures are warming at a rate of about 0.27°C per decade. That’s nearly 50% faster than the close to 0.2°C-per-decade warming rate of the 1990s and 2000s, indicating an acceleration of global warming.
Human-caused and total observed average global surface temperature increase since the Industrial Revolution. Created by Dana Nuccitelli with data by https://climatechangetracker.org/igcc from June 17, 2025.
That warming causes the water in the ocean to expand and land-based ice to melt, both of which contribute to rising sea levels. Since 1900, global sea levels have risen by nine inches, at an average rate of 1.85 millimeters per year. But the rate of sea level rise since 2000 has been twice as fast, at 3.7 millimeters per year. And over the past decade it’s risen faster yet, at 4.5 millimeters per year. In other words, sea level rise is also accelerating.
“Unfortunately, the unprecedented rates of global warming and accelerating sea-level rise are as expected from greenhouse emissions being at an all-time high,” University of Leeds climate scientist and the study’s lead author Piers Forster wrote by email.
Global mean sea level rise since the early 20th century, accelerating since the start of the 21st century. Created by Dana Nuccitelli with data by https://climatechangetracker.org/igcc from June 17, 2025.
A thin silver lining
Most, but not all, of the findings in the new paper are grim. For example, although humanity will almost certainly miss the more ambitious 1.5°C target in the Paris agreement, the study finds that its primary target of limiting global warming to 2°C remains within reach. At current emissions rates, 2°C global warming will be breached around midcentury, but that still leaves several decades to bring emissions down.
“Future emissions control future warming,” Forster said. “And if the world were to rapidly act on carbon dioxide and methane emissions, we could halve the rate of warming.”
The study identifies glimmers of hope that climate policies and solutions around the world could soon begin to move emissions in this direction.
“I think there is not much silver lining in the report per se given the apparent acceleration of warming,” Hausfather said in an email to Yale Climate Connections. “But I would note that global CO2 emissions have slowed notably over the past 15 years or so, and the cost of clean energy continues to fall. We are clearly moving away from the worst-case emissions scenarios, even if we are still heading toward potentially catastrophic warming of 3°C by 2100.”
China will be a key player in determining the future evolution of Earth’s climate. Because of its large population and rapid economic growth, China is responsible for nearly one-third of global climate pollution. But as the result of a rapid deployment of clean technologies, China’s emissions have begun to slightly decline over the past year.
“This is also the decade when global [greenhouse gas] emissions could be expected to peak and begin to substantially decline,” the report’s authors conclude. “Depending on the societal choices made in this critical decade, a continued series of these annual updates could track an improving trend.”
The phrase “Future emissions control future warming,” concerns me. It assumes that the fate of the climate is still in our hands. Human emissions represent just 4% of total emissions, yet this phrase implies that nothing we've done has irreversibly increased that other 96% of emissions.
Evan,
My understanding is that the global warming, climate changes, and sea level rise due to increasing ghg levels is due to the 4%. How much future harm is done is indeed totally dependent on what global humanity collectively does in the future.
What global humanity has done to date, including the failure to dramatically reduce activities that undeniably increase ghg levels, especially the most fortunate failing to lead the transition to less harmful ways of living (and the related failure of the most fortunate to help those who are tragically unfortunate have better less harmful life experiences), made things worse now than it had to be.
If humans stop causing impacts that continue to increase ghg levels then the global warming, climate change and sea level rise impacts will stop getting worse.
So, “Future emissions [do] control future warming,” when those emissions are understood to be the human caused excess emissions increasing ghg levels (the 4%). And that understanding is reinforced by the complete quote “Future emissions control future warming, … And if the world were to rapidly act on carbon dioxide and methane emissions, we could halve the rate of warming.”
And that understanding can be extended to state that: If global humanity were to rapidly act on carbon dioxide and methane emissions and rapidly act to develop and implement effective sustainable reduction of levels of ghgs then the maximum level of future harm due to future human impacts will be less than would otherwise be created.
A reminder about an often ignored aspect of reality regarding effective methods to limit the total future harm of human climate change impacts. A significant action that can immediately be implemented, needing no technological development or growth of production and use of a technology, is the ending of energy use that, while potentially enjoyable or popular or profitable, is not required to live a decent healthy helpful (unharmful) life.
Technological developments that require less energy consumption should be the priority. Less energy use would reduce the harm done during the transition from harmful unsustainable energy systems to harmless sustainable energy systems.
OPOF, in attempting to be brief and to the point, I created a misunderstanding.
I understand that historically the other 96% of GHG emissions has been in balance with equivalent sinks, leaving the 4% due to humans to cause the warming. My point is that as we warm the planet, it is likely that the natural emissions will increase, and it is equally likely that the sinks that have removed the natural emissions, will decrease. Hence, the imbalance caused by our 4% emissions will likely be added to by the combination of increased natural emissions and decreased natural sinks. We don't have to perturb the 96% too much to completely swamp our efforts to reduce GHG emissions.
I think it is arrogant to assume that we understand the natural world so well and the current state of the climate as to assume that the future continues to remain in our hands. Climate scientists have been scrambling the last few years to explain the sudden increase in warming. Their scrambling to understand this increased warming is a good example of why I don't think that future warming is entirely in our hands.
My point is that even if we eradicated every last human from the planet (one of the many possible Net-0 strategies), that the warming would likely continue due to how we have already affected the balance of natural GHG sources and sinks. You can call this my opinion, but it is based on a healthy respect for just how delicate our ecosystem is, and hard we have been pushing it the last century or so.
Evan,
Thank you for clarifying the focus of your comment @1. My take is that you are concerned that feedback mechanisms that will cause significant unanticipated warming far into the future have been triggered by human impacts to date.
My understanding is that, at the present and near future level of human impacts (with peak total impacts significantly lower than 2.0 C), sea level rise is one of the few impacts that will be increasing for a long time after human activity stops increasing ghg levels.
Recent years of unexpected global average surface temperatures raises questions. However, my point remains that how bad things get, including how much unexpected feedback is triggered, is totally controlled by human actions.
Lower total peak human ghg impacts in the future will produce lower amounts of harmful consequences in the future.
The wording in the article that concerns me is the moving away from the Paris Agreement goals by saying “the study finds that its [the Paris Agreement] primary target of limiting global warming to 2°C remains within reach."
As presented by the Wikipedia item for the Paris Agreement:
The Paris Agreement has a long-term temperature goal which is to keep the rise in global surface temperature to well below 2 °C (3.6 °F) above pre-industrial levels.
Limiting impacts to 2 degree C does not reach the Paris Agreement objective. And every bit of increased impacts increases the risk and magnitude of harmful unexpected feedback.
OPOF@4, you state,
"However, my point remains that how bad things get, including how much unexpected feedback is triggered, is totally controlled by human actions."
IMO, we simply do not understand the ecosystem well enough to claim that humans are still in complete control of the ecosystem and all feedbacks.
Evan,
My Stating
“how bad things get, including how much unexpected feedback is triggered, is totally controlled by human actions.”
is not the same as stating
“we understand the ecosystem well enough to claim that humans can completely control the ecosystem and all feedbacks.”
My understanding includes the knowledge that we do not understand the global and local ecosystem(s) well enough to develop and implement geoengineering activities that will produce a sustained desired controlled reduction of climate change harm to the global ecosystem(s) and all feedbacks.
My understanding is that human impacts that increase ghg levels will make things worse in the future. And humans are the only beings on the planet who can control how harmful they are collectively. Tragically, that ‘control’ can include collectively being more harmful because higher status, more influential, members of humanity are able to gather support for being more harmful and less helpful to others.
Evan @3,
You set out your "point" that, in your opinion, "the warming would likely continue due to how we have already affected the balance of natural GHG sources and sinks" even after every humanity has effectively disappeared.
The carbon cycle is understood enough (and has been understood for some time) to allow studies to conclude that the carbon sinks will continue to outweigh any natural sources and the resulting reduction in GHG will roughly balance the remaining unfulfilled warming from our emissions. Thus warming effectively stops once our emissions stop.
There has been work looking at the potential for large new sources of natural emissions or the stifling of sinks. These include the likes of methane emissions from melting permafrost or warming Arctic seas, the cascading collapse of econsystems like the Amazon rainforest or the capacity of oceans to absorb CO2 in a warmer world. (Your mention of "feedbacks" @5 - you may have specific examples in mind.) Some of this past work has sounded pretty worrying but such worrying findings have not survived full analysis.
Beyond 'net zero', there are also calls for 'net-negative emissions' that don't get discussed as much as they should. These are seen as globally necessary if our emissions are not cut quickly enough, a situation which seems pretty certain to happen. 'Net-negative' does not address future warming but works to reduce the time over which peak warming continues.
MA Rodger@7, thanks for the review of the carbon cycle. I understand the principles here: I just don't accept the confidence with which the claims are made that carbon sinks will take care of carbon sources if we were to reach net-0.
But my real point is this. I caution people to listen less to all of the optimistic talk about how emissions are starting to flatten out and getting ready to decline, and watch instead what is happening to the Keeling Curve, because it represents the net effect of the carbon cycle. If the carbon cycle is really going to clean up our mess, then that should be reflected in the Keeling Curve (I understand that currently about half of our GHG emissions are absorbed by the oceans and the land).
But so far the Keeling Curve continues to accelerate upwards, and the annual average rate of increase is a colossal 2.5 ppm! I wonder if people really appreciate the magnitude of that kind of push on our environment?
For the Keeling Curve to continue its upward acceleration in the face of so much positive, optimistic emissions news means that either the carbon cycle is not doing what we thought it should be doing, or our emissions estimates underestimate reality. Either way, we are a long, long way from achieving anything like Net-0.
Perhaps my skepticism originates because I am a professional modeler and understand the uncertainties of such modeling. But beyond that, I am concerned about the confidence placed in our emissions estimates. The US is heading down a path to obfuscate climate science. Certainly such obfuscation is occurring elsewhere. For these reasons and more I encourage people to follow the trajectory of the Keeling Curve, because in the end, it is rrepresents the unvarnished truth about what is really happening to the carbon cycle.
Evan,
Thank you for further clarifying what your primary concern is.
I fully agree that the Keeling Curve, and the concentrations of all other ghgs, should be what people pay attention to. Those measurements should be the basis for claims regarding the success of efforts to rapidly end the harmful human impacts and hopefully limit the harmful climate change impacts on future generations to far less than 2.0 degrees C (with unprofitable carbon extraction being required to bring excess impacts back down to 1.5 degrees C).
There is a chance that the recent set of unexpectedly warm years are the result of human impacts to date triggering significant long lasting feedbacks that are not yet identified and understood.
But I think it is significantly more likely that the ways that the rate of ‘human global warming and resulting climate change impacts’ are measured are inaccurate. And those inaccurate measurements lead people to make inaccurate claims, claims that are inconsistent with the Keeling Curve and the measurement of other ghgs.
To be clear, a leveling off of the annual rate of human impacts does not mean that the Keeling Curve would level off. Humans having sustainably achieved net-zero global warming impact would be indicated by the Keeling Curve leveling off and starting to slowly sustainably decline.
Evan @3 said: "My point is that as we warm the planet, it is likely that the natural emissions will increase, and it is equally likely that the sinks that have removed the natural emissions, will decrease. Hence, the imbalance caused by our 4% emissions will likely be added to by the combination of increased natural emissions and decreased natural sinks. We don't have to perturb the 96% too much to completely swamp our efforts to reduce GHG emissions."
My understanding is your scenario would only happen if we let warming get so high that we crossed certain tipping points, so that even if we froze emissions at that point in time, CO2 and methane release would continue at very substantial levels thus offsetting or swamping our efforts to then drastically cut emissions. We haven't reached that point, and my understanding is we wont provided we keep warming under 2 degrees. Bear in mind theres a fine line between a positive feedback which stops when the primary forcing stops, and crossing a tipping point where emissions become self sustaining. And Im not sure how self sustaining they would really be.
Evan @8,
(Hopefully my reply here, your third to #7, isn't piling too much at you.)
Quantifying CO2 global emissions is reliant on the data reported and that data does suggest that emissions are still edging up. And these annoying still-rising emissions will result in accelerating increases in atmospheric CO2 levels and leaving net zero further away than ever.
The question of whether "the carbon cycle is not doing what we thought" revolves around Af, the Airborne Fraction which does wobble quite a bit year-to-year. Studies do show that there is no sign of an increasing Airborne Fraction (eg Bennett et al (2024) 'Quantification of the Airborne Fraction of Atmospheric CO2 Reveals Stability in Global Carbon Sinks Over the Past Six Decades', their Fig4 below). Of course, if there were an increasing Airborne Fraction, it would be a game-changer. But the major long-term sink we rely on is the ocean absorbtion which is a case of reasonably straightforward chemistry. Over a millennium the oceans will take up about 75% of our emissions.
A simplistic reassurance can be gleaned from the work of the Global Carbon Project whose annual data shows annual emissions and the annual atmospheric increase (both in GtCarbon) with no perceptible sign of increases in the Airborne Fraction.
MA Rodger@11, thank you very much for your detailed answer and for the explanation about AF.
Katharine Hayhoe has an analogy about driving on a dead-straight road in Texas and saying that "relying on past climate patterns is no longer a reliable guide for the future because of the speed of climate change." (this is the Google AI version of her quote). It is reassuring in a sense that AF has been steady for so long, but ...
Despite the data you showed, because we are pushing the climate so hard (CO2 rising on average 2.5 ppm/yr), I remain skeptical that we can really be sure that AF will remain constant into the future. But for the sake of harmony, can we figure out wording that we all agree on.
Do you agree that climate scientists use 2C warming as a guesstimate of the point at which we begin to lock in warming in the pipeline? In other words, even if we achieved Net-0 after crossing the 2C warming threshold, do climate scientist agree that at that point we would have locked in additional future warming?
A lot of this is semantics, because the socio-political inertia does not give me much hope that we will put on the brakes before we cross the 2C barrier, but I would like to arrive at a common understanding so that my posts here don't seem to be at odds with professional climate science.
And yet here's evidence that the models are wrong about one of their most fundamental predictions: accelerating sea level rise. Instead, this study using 60 years of tidal gauge data show an annual rate of approximately 1.5mm, not 3-4mm.Oops!
https://www.mdpi.com/2077-1312/13/9/1641
Blockbuster sea level study may turn climate change orthodoxy on its head!
[BL] You pointed to the same paper on another thread. It is considered bad form to thread-blast the same comment in multiple places.
No matter how many times you tell us about the paper, it is still crap. Read the moderator's comment that has been added to your first post.
The only thing that is getting turned on its head is the hope that one of these days the contrarians will be able to come up with an analysis that isn't based on bad assumptions and bad methodology.
It's worth repeating the opening sentence of the RealClimate post referred to in the moderator's comment on your other posting:
Here we go again. An obscure, methodologically poor, paper published with little to no review makes a convenient point and gets elevated into supposedly ‘blockbusting’ science by the merchants of bullshit, sorry, doubt.
I apologize for my two posts regarding the recent Voortman article; I am new to this site and didn't mean to make two posts. From the comments following the RC response to Voortman's article it does seem to me that as usual there are an extraordinary number of variables that confounds are ability to get reliable numbers. I have a new appreciation for the complexity of the subject. It does at least appear to me that there is an excessive degree of certainty with regards to "the truth" on both sides.
BTW how do we know that there was little to no review? (again I apologize if this is easily determined)
[BL] Regarding lack of review.
MDPI journals have a very bad reputation. They strongly resemble a "pay as you play" publisher, where the only real review is whether or not your credit card charge clears. Again, read the Wikipedia link I gave you before.
If you look at your own link to the paper, you will see that the paper was first submitted to the journal on June 20, and a revised version submitted on August 15 - which means that reviews and changes were completed in less than two months. Final acceptance followed on August 20 - only 5 days after re-submission. These time frames are very short for proper review, and strongly suggest that very few changes were requested by reviewers.
The review comment are available on the journal's web page, They are mostly superficial in nature. The reviewers have either not done a serious evaluation of the methodology, or they do not have the expertise to do a thorough review of the methodology.
In the RealClimate post, they have a link to a response by Kopp et al. In that review, one of the points to make is that the Voortman and de Vos paper ignores many relevant papers in the literature. A good review by a knowledgeable reviewer would have pointed that out. And an evaluation by a good editor would have insisted that the authors fix that in their paper. All signs pointing to a quick and dirty review - possibly by friends of the authors.
The fundamental statistical error that Voortman and de Vos made was that they argued there is no global signal of acceleration, but they used a statistical test that assumes that there is no connection between the tidal stations (statistical independence). You can't assume there is no connection when you start your analysis, and then conclude that your analysis demonstrates that feature. Again, a proper review by a knowledgeable reviewer would have pointed this out.
Radman365:
You say "It does at least appear to me that there is an excessive degree of certainty with regards to "the truth" on both sides." There are two truths here to determine.
1) Is sea level rise accelerating? On one side we have a paper published in an obscure journal by authors who have produced erroneous analysis before on this topic and did not review their work with anyone with expertise in the subject. On the other we see hundreds of scientists who have discussed the data extensively with each other and reached a consensus that sea level rise is accelerating. The hundreds of scientists have identified multiple large errors in the obscure authors work.
In this case it is relatively simple to do the analysis and the results are very strongly indicating acceleration. I note that in addition to the tide guage data the hundreds of scientists have independant satalite data that reaches the same conclusion. The obscure scientists simply do not know what they are doing and have screwed up. Why did they ignore the satalite data that showed their analysis was incorrect?
The data is clear, sea level rise has accelerated over the past 50 years. Ignoring half of the data and assuming that sea level rise is independant at different locations in the world is simply an ignorant way to look at the data.
2) The important question is: will sea level continue to accelerate in the future? Data from the future is difficult to obtain. Scientists are debating what we should expect in the future. A few thnk it will not be too bad while others think it will be catastrophic. The fact that sea level rise is accelerating makes many of us very worried. The last time CO2 was over 400 ppm sea level was over 20 meters higher than today. I note that every time an IPCC report is released the projections of sea level rise increase.
You are welcome to think that sea level rise will not be too bad. That might be the case. Since sea level rise is accelerating, most of the readers here thinik we should be concerned about it. 20 meters of sea level rise would submerge most of the major cities in the entire world, although it will take a long time. Since the answwer to sea level rise is installing cheap renewable energy everywhere, why not try supporting renewable energy in your community?