Worth pointing out that the 1930s heat waves in the US were HUMAN CAUSED. Deep plowing ruined the prairie soils, which in dry times became bare and absorbed more sunlight, enhancing the drought and heating. The problem was solved by better agricultural practices and tree-planting.
Meehl, Gerald A., et al. (2022). "How the Great Plains Dust Bowl Drought Spread Heat Extremes around the Northern Hemisphere." Scientific Reports 12: 17380 [doi:10.1038/s41598–022–22262–5].
Why doesn’t the recent 30-year period, the most widespread, human caused period of soil degradation at global scale, feature in communication about heat extremes and hemispheric teleconnection?
Soil moisture has been a key component of models since the outset (one of Manabe's very first jobs was finding data on this), but it seems only recently that it's become clear that there is net drying of soils. Land heats a lot seasonally and evaporates, oceans don't change much, so net water migrates in rain as well as rivers to the seas, D'oh! see the two paragraphs preceding my note 30 here: https://history.aip.org/climate/impacts.htm#N_30_
not sure. I don't have access to the book chapter. Aligned with Spencer Weart's input about the 1930s USA low plains (liked by Hausfather), December 2024 media attention about degradation identified "the main culprit" as unsustainable agricultural practices with recent degradation hotspots in dry regions such as "south Asia, northern China, the High Plains and California in the US, and the Mediterranean. A third of humanity now lives in drylands, which include three-quarters of Africa." So we know the same processes in Weart's input are not limited to history, and we know it's happening at much wider scale today. Sounds like a secondary pressure "comes from climate disruption, which intensifies land degradation through prolonged droughts and intensified floods." Why not put 2 and 2 together and realize degradation has something to do with many places setting new all time temperature records? Why pretend that it doesn't? https://www.theguardian.com/environment/2024/dec/01/land-degradation-expanding-by-1m-sq-km-a-year-study-shows
Ok so it’s getting hotter. What are we going to do about it? Realistically? Is it practical to think we can manage CO2 in the atmosphere when the biggest emitters are emitting more and more? Shouldn’t we help our descendants by being pragmatic and preparing? We can try to forecast all the negative things that are going to happen but if our solution is to affect CO2 in the atmosphere we’ll be letting down those who follow us. If it’s raining put on a rain coat because you can’t stop the rain.
I doubt there is anything that can be done without a significant downsizing of economies and lifestyles but no-one wants to do that. Even with the push for so-called renewable energy, everything in the global civilisation is dependent, in some way, on fossil fuels.
Please remember that we aren't seriously doubting that the earth is gradually warming from the coldest period in about 500 million years (if you believe that we can actually do that). Please see:
Please look at the graph for a long time. We are coming out of the coldest period in history. Does it not make some sense that the "all time heat records" set globally are also just the earth's way of moving back to equilibrium? Whether we are pumping CO2 or not into the atmosphere, the earth is going to warm anyway. Look at the graph.
The argument for skeptics is non sequitur. Meaning, while the earth is most definitely warming, that warming is not translating into the misery and death as predicted, but rather just the opposite. We enjoy the longest life expectancy in the history of humankind. Right now.
To think otherwise--well--just look at the graph again. It is quite astounding.
But its not hard to understand what their paper says about the role of CO2 in driving warming; its right there in the abstract:
"There is a strong relationship between PhanDA GMST and CO2, indicating that CO2 is the dominant control on Phanerozoic climate. The consistency of this relationship is surprising because on this timescale, we expect solar luminosity to influence climate. We hypothesize that changes in planetary albedo and other greenhouse gases (e.g., methane) helped compensate for the increasing solar luminosity through time. The GMST-CO2 relationship indicates a notably constant “apparent” Earth system sensitivity (i.e., the temperature response to a doubling of CO2, including fast and slow feedbacks) of ∼8°C, with no detectable dependence on whether the climate is warm or cold."
Zeke, thanks for responding. I'm confident you have discussed this in more detail with the authors. However, the basic findings of this study are quite easy for even the casual observer to see on the graph. No spin zone here. Whether we are creating catastrophic heat or not with our fossil fuel use remains a mystery. We have a long geographic history showing a much "warmer" equilibrium. I think anyone with basic scientific knowledge will admit this. This really makes it difficult to know how much we are actually warming vs. underlying unknown forces that Gavin et al. admitted to just last year.
Regardless of all the above, we are being told that it's not necessarily the warming, but the speed of warming that is catastrophic. It may be warming at warp speed or not. The real world data all tells me one thing: Human flourishing is at a peak and human suffering is at it's trough RIGHT NOW compared to all recorded human history. It is a heavy burden of proof for you, Andrew and others to convince me--a medical doctor with almost 20 years of research regarding OUTCOMES of said warming, to your side. Because of all this, I'll remain firmly in the skeptical camp until I see otherwise. Thanks,
Yes, everything is human caused, even earthquakes? I venture to suggest that similar heat patterns occurred during the Minoan warming, the Roman warming and the Medieval warming. Were they human caused too? The question facing science is what causes these 800-year warming events? My studies are tedious and slow due to my day-job taking my time, but they show that the sun is probably not a perfect sphere and has slight bulges that MIGHT be caused by a combination of the sun's rotation and the orbits of the large masses in the solar system (especially Jupiter) over several billion years. However, the cyclicity identified to date does not correspond with the 800-year cyclicity of these warming events. So, my hypothesis remains speculative at present, much like the anthropogenic CO2 hypothesis is. Potentially valid but a long way from proven fact. It is important to be honest about these hypotheses.
"So, my hypothesis remains speculative at present, much like the anthropogenic CO2 hypothesis is. Potentially valid but a long way from proven fact."
I might be missing the joke, but proof is for formal logic and distilled spirits. Your hypothesis differs from anthropogenic CO2-driven global warming in a crucial way: yours is idiosyncratic, and has no empirical or peer support; while the latter is as close to verified as any geophysical theory can be, by both the consilience of empirical evidence over two centuries of advancing science, and the current overwhelming peer consensus for it. Not everyone has to agree, just an effective majority of US voters: AGW is more than sufficiently confirmed to justify collective intervention in the US energy market, to take the profit out of transferring fossil carbon to the atmosphere.
"It is important to be honest about these hypotheses."
On that much we agree! TBH: whatever your background, if you actually think your "hypothesis" is as well-supported as AGW is, you're afflicted with the Dunning-Kruger Effect. Science is first and foremost a way of trying hard not to fool yourself: "The first rule is you must not fool yourself, and you are the easiest person to fool" (Feynman). "Intersubjective verification", i.e. consensus among trained, disciplined, mutually skeptical peers, is as fundamental to the success of the centuries-long, open-ended, cross-cultural scientific enterprise as rigorous empiricism and strict reasoning are. Verifiable, useful knowledge can't be self-correcting or cumulative without peer consensus at every increment. Anyone who tells you "consensus isn't science" is trying to fool you. And if you doubt the consensus but think the error lies with it, not you, then you're willfully fooling yourself!
Unsupported claims and read-only iteration of obstructionist dog whistles will be ghosted. What else is there?
Yes, it's sad that the guy hallucinates that variability is due to bulges in the sun when it's obvious that tidal cycles have much to do with all the zero-sum changes.
I had trouble understanding this but I gather this is the monthly mean and hottest absolute value which really restricts it to deep summer only. Why not temperature departures from a base period to let in all months? Then I suspect a lot of winter months will be the hottest change.
Folks tend to focus on summer heat waves, so this is specifically about when annual (monthly) record maximum temperatures occur. But I agree that you could look at the highest monthly anomaly of the year, which would tend to highlight more winter months.
I also suggest that it is much better to use three month running means, as proxy seasons. One month can be dominated by a single synoptic event and seasons cut down on that noise a lot.
So just to be clear Zeke. A monthly slice for each zone would produce 12 highest record temperatures (eg highest in Jan = 2010, highest in Feb = 1999, highest in Mar = 2023 etc). So of the 12 record breakers per zone, how did you conclude on which decade you'd show on the graph / atlas given the records may span several decades?
Point taken on cherry-picking but it is quite remarkable just how variable weather is and that it all too easy to see outlier events in the present that actually aren’t outside of the historical range of extremes.
Hot days are obviously the clearest result of a warming planet but many of the other hazardous weather-associated extremes in precipitation, flooding, winds, cyclonic activity and drought aren’t in some new catastrophic regime that they often get painted as being in, agreed? I think of these phenomena as at most warming-enhanced instead. Enhancement that will, I concede, increase over the next 50 to 70 years or longer depending on how the energy transition and any climate interventions go.
Thanks for the concession. Your comment is perfectly reasonable, but it just means there's a crucial time dimension to the political issue. My own advocacy for collective decarbonization is motivated not by headline-grabbing weather events but by pejorative secular empirical trends, some of them demonstrably accelerating.
And while it may be "all too easy" to see outliers that actually aren't, daily highs in Lytton, BC for three days in 2021 were clearly outside any reasonable historical range (https://en.wikipedia.org/wiki/Lytton,_British_Columbia):
"During heat waves, Lytton is often the hottest spot in Canada despite its location north of 50°N in latitude. [Yet] In three consecutive days of June 2021, it broke the all-time record for Canada's highest temperature, ending at 49.6 °C (121.3 °F) on June 29. This is the *highest temperature ever recorded north of 45°N and higher than the all-time records for Europe and South America*. The next day (June 30), a wildfire swept through the valley, destroying the majority of the town."
My emphasis. Human terror and grief notwithstanding, if that doesn't counter the insufficient-sample objection, nothing will.
Also: Yes, the accumulation of global heat content is enhanced by fossil carbon emissions, and will continue at least until emissions cease. But, it's already taking a calculable toll in lives as well (https://www.nytimes.com/2025/07/09/climate/europe-heat-waves-deaths.html). I, for one, find that moderately "alarming". Gotta leave room at the top for "globally apocalyptic" when it's called for!
Good analysis. Aside from highlighting the clear need for action to mitigate this rise, the rising temperature trends draw attention to the urgency of adaptation requirements. There is a significant shortfall in resilience to the level of change that's already baked into our future climate.
So not to counter the conclusions of this which I totally believe, but I think this chart might be exaggerate the effect in one way. The most recent decades will always have the most records as they eliminate records from previous decades. For instance, if you did this say only using data up the year 2000, the 1990 would also show a peak. The question would be how much lower would the peak be than more recent decades.
That’s not quite how the statistics work here. If the climate were stationary (with short term unforced variability) there would be a roughly equal likelihood of a record being set in each decade (at least for the 90 years where all cells shown have complete data).
“How much of this is underlying earth returning to equilibrium?”
We would need to explain why temperature decided relatively abruptly to quite rapidly return to equilibrium about 50 years ago, after varying relatively little for the preceding couple of thousand years.
We would also need a separate explanation as to why the atmospheric changes that have occurred over the same period, and which have the physical properties to cause a change in radiative forcing, did not do so.
That seems rather a lot of ad hoc-ery to try to explain something that already has a much more satisfactory explanation.
Don't you find it a little presumptuous to think that we can look back millions of years to see how quickly temperatures changed within a 50 year timespan with any sort of accuracy? Any casual observer is going to ask, "If your point is to show abruptly the temps have been changing in the past 50 years, you'd better be darn sure you're using the same instruments to measure the acceleration and velocity of temp changes 50 million years ago too so we're comparing apples to apples".
Additionally, THE BALL IS IN YOUR COURT TO PROVE THAT CURRENT SAID "ABRUPT WARMING" IS ACTUALLY CAUSING CATASTROPHIC OUTCOMES. As a medical doctor with almost 20 years studying human health outcomes from the "climate change catastrophe", I find none. In fact, again, we are currently living in the best conditions ever recorded in human history. There is a distinct POSITIVE CORRELATION regarding warming and human flourishing. You carry a very heavy load to convince any of us that this "abrupt change" is not only not beneficial, but actually detrimental.
“ Additionally, THE BALL IS IN YOUR COURT TO PROVE THAT CURRENT SAID "ABRUPT WARMING" IS ACTUALLY CAUSING CATASTROPHIC OUTCOMES”
Well, for a start, if we are discussing the cause of warming (and I thought we were), then obviously I am under no obligation to “prove” anything about a different subject altogether.
But as it happens, I am not greatly surprised that we don’t seem to be observing “catastrophic outcomes” in 2025, because I wasn’t aware that any such predictions were ever made. Of course, it doesn’t help that “catastrophe” is a non-scientific, highly subjective term.
Furthermore, while I completely agree that things have gotten much better for humans in recent times, I think it is rather questionable to attribute it to warming rather than advances in knowledge, technology and health.
"I am not greatly surprised that we don’t seem to be observing “catastrophic outcomes” in 2025"
I think you're "winning" the "debate" with Scott, and your understanding is authoritative. But the immediate argument is about the definition of "catastrophe". Clearly it's in the eyes of the beholder, not intersubjectively verifiable! Again, I ask whether attributable victims of the current abrupt warming are allowed input.
The report employs rapid-attribution methods, which pseudoskeptics dismiss as hand-waving. Scientifically metaliterate readers have a more nuanced view. The attributable victims no longer have an opinion. Their families presumably do, however. Again, must their numbers reach some threshold value before we'll all agree to "catastrophic"?
“ Don't you find it a little presumptuous to think that we can look back millions of years to see how quickly temperatures changed within a 50 year timespan with any sort of accuracy?”
I asked you to consider why temperatures only started shooting up recently, after varying little for thousands (not millions) of years. If you are now suggesting that temperature variations similar to the last 50 years have been going on for thousands of years but the reconstructions are not sufficiently accurate to detect them, then obviously you are undermining your original thesis that the recent warming is simply a return to equilibrium with past higher temperatures.
But as it happens, the temperature reconstructions of the last few thousand years do seem to have the necessary resolution to rule this out. Temperature swings similar to recently (~1°C in 50 years) would appear to be well outside the error bars in those reconstructions.
The next problem is that, as I mentioned, there is a credible explanation for the recent warming (anthropogenic greenhouse forcing) but nothing comparable is known to have been going on over the last few thousand years. So you now have to come up with a new, currently unknown mechanism to explain changes that are not actually observed in temperature reconstructions.
See what I mean about the amount of ad hoc-ery involved?
Thanks Kingston. Freely extending your ineluctable, Occam's-Razor based objections: AFAICT, any proposal for an intrinsic, long-term equilibrium to which global heat content is returning, is religiously motivated (e.g. https://cornwallalliance.org/evangelical-declaration-on-global-warming). As you're aware, more pragmatic denialists love to tell us "climate is always changing!11!" "We", i.e. climate realists, know the latter is true inside the bounds published last year in *Science*: for the last 485 million years, within confidence limits, GMST has ranged from 11° to 36°C. And we know that throughout that range, GMST has always changed on geologic time scales, for known, or at least scientifically supported, geophysical reasons.
Sadly, we also know there's no enforceable or even existential requirement for denialists to be rational, so they're free (subject to forum moderation) as well: free, that is, to entertain both "climate has always changed" and "climate is returning to an [indeterminate] equilibrium" zombie obstructionist memes simultaneously. We, OTOH, know that the current GMST trend of >0.2°C/decade is unprecedented in recorded human history, wholly anthropogenic, and already causing casualties in excess of a preindustrial, quasi-stable climate state. I, for one, am as certain as I need to be that no magical indwelling equilibrium or teleological benevolence is going to intervene before the end of my "natural" [they'll take my Medicare from my cold, dead hands -MA] life.
Scott has long declared his determination not to be "terrified" by climate science, even though he's made an own-goal by linking to that *Science* article. "For the lurker" (h/t NSAlito), then, from the "Structured Abstract:
"Here, we present PhanDA, a reconstruction of GMST over the past 485 million years, generated by statistically integrating proxy data with climate model simulations. PhanDA exhibits a large range of GMST, spanning 11° to 36°C...
"...We find that Earth’s temperature has varied more dynamically than previously thought and that greenhouse climates were very warm. CO2 is the dominant driver of Phanerozoic climate, emphasizing the importance of this greenhouse gas in shaping Earth history."
OK. In the 200 years of advancing science since Fourier's proposal** of the greenhouse*** effect from planetary heat budget calculations, generations of trained, competitive, mutually-disciplined scientists have come far in their understanding of the forces determining Earth's climate and its changes over 485 my. There are cyclic astronomical partial drivers on 10, 20 and 100-ky scales, but longer or shorter periods don't emerge statistically from random variation around secular trends over random intervals, and no genuinely periodic forces can be detected. The burden is on contrary claimants to get past peer-review.
For newcomers to the history of climate science, I strongly recommend Dr. Weart's book "The Discovery of Global Warming". My brother, with a PhD in Economics, said it brought him up to speed efficiently! Meanwhile, the cited *Science* article helps to increase our confidence in the models used to project future GMST trends over a range of hypothetical CO2 concentration pathways.
That's my shot. Denialist tar babies will keep on JAQing off. Somebody else take the mallet. ["Block that metaphor!" -*The New Yorker*]
** Disclosure: ChatGPT suggested "proposal" instead of my choice, "induction". Like all my comments unless indicated, the rest is organic, if not intelligent 8^).
*** Not his word, and IMO a poor analogy, but I'm not the boss of colloquial English. Nobody is.
Worth pointing out that the 1930s heat waves in the US were HUMAN CAUSED. Deep plowing ruined the prairie soils, which in dry times became bare and absorbed more sunlight, enhancing the drought and heating. The problem was solved by better agricultural practices and tree-planting.
Meehl, Gerald A., et al. (2022). "How the Great Plains Dust Bowl Drought Spread Heat Extremes around the Northern Hemisphere." Scientific Reports 12: 17380 [doi:10.1038/s41598–022–22262–5].
Why doesn’t the recent 30-year period, the most widespread, human caused period of soil degradation at global scale, feature in communication about heat extremes and hemispheric teleconnection?
Soil moisture has been a key component of models since the outset (one of Manabe's very first jobs was finding data on this), but it seems only recently that it's become clear that there is net drying of soils. Land heats a lot seasonally and evaporates, oceans don't change much, so net water migrates in rain as well as rivers to the seas, D'oh! see the two paragraphs preceding my note 30 here: https://history.aip.org/climate/impacts.htm#N_30_
How's this?
https://link.springer.com/chapter/10.1007/978-3-540-72438-4_7
not sure. I don't have access to the book chapter. Aligned with Spencer Weart's input about the 1930s USA low plains (liked by Hausfather), December 2024 media attention about degradation identified "the main culprit" as unsustainable agricultural practices with recent degradation hotspots in dry regions such as "south Asia, northern China, the High Plains and California in the US, and the Mediterranean. A third of humanity now lives in drylands, which include three-quarters of Africa." So we know the same processes in Weart's input are not limited to history, and we know it's happening at much wider scale today. Sounds like a secondary pressure "comes from climate disruption, which intensifies land degradation through prolonged droughts and intensified floods." Why not put 2 and 2 together and realize degradation has something to do with many places setting new all time temperature records? Why pretend that it doesn't? https://www.theguardian.com/environment/2024/dec/01/land-degradation-expanding-by-1m-sq-km-a-year-study-shows
Thank you for the analysis; the chart would be improved with a note that the 2020 decade contains only the first 5 years of data....
Compulsory super at work?
Ok so it’s getting hotter. What are we going to do about it? Realistically? Is it practical to think we can manage CO2 in the atmosphere when the biggest emitters are emitting more and more? Shouldn’t we help our descendants by being pragmatic and preparing? We can try to forecast all the negative things that are going to happen but if our solution is to affect CO2 in the atmosphere we’ll be letting down those who follow us. If it’s raining put on a rain coat because you can’t stop the rain.
I doubt there is anything that can be done without a significant downsizing of economies and lifestyles but no-one wants to do that. Even with the push for so-called renewable energy, everything in the global civilisation is dependent, in some way, on fossil fuels.
The answer of what needs to be done lies within your answer, Doug, if only you read it carefully.
Hi Zeke,
Please remember that we aren't seriously doubting that the earth is gradually warming from the coldest period in about 500 million years (if you believe that we can actually do that). Please see:
https://www.science.org/doi/10.1126/science.adk3705
Please look at the graph for a long time. We are coming out of the coldest period in history. Does it not make some sense that the "all time heat records" set globally are also just the earth's way of moving back to equilibrium? Whether we are pumping CO2 or not into the atmosphere, the earth is going to warm anyway. Look at the graph.
The argument for skeptics is non sequitur. Meaning, while the earth is most definitely warming, that warming is not translating into the misery and death as predicted, but rather just the opposite. We enjoy the longest life expectancy in the history of humankind. Right now.
To think otherwise--well--just look at the graph again. It is quite astounding.
Hi Scott, I suspect I've read that article a bit more closely than you have, given that I talked to the lead authors about it and they helped me write an earlier article here: https://www.theclimatebrink.com/p/climate-skeptics-have-new-favorite
But its not hard to understand what their paper says about the role of CO2 in driving warming; its right there in the abstract:
"There is a strong relationship between PhanDA GMST and CO2, indicating that CO2 is the dominant control on Phanerozoic climate. The consistency of this relationship is surprising because on this timescale, we expect solar luminosity to influence climate. We hypothesize that changes in planetary albedo and other greenhouse gases (e.g., methane) helped compensate for the increasing solar luminosity through time. The GMST-CO2 relationship indicates a notably constant “apparent” Earth system sensitivity (i.e., the temperature response to a doubling of CO2, including fast and slow feedbacks) of ∼8°C, with no detectable dependence on whether the climate is warm or cold."
Zeke, thanks for responding. I'm confident you have discussed this in more detail with the authors. However, the basic findings of this study are quite easy for even the casual observer to see on the graph. No spin zone here. Whether we are creating catastrophic heat or not with our fossil fuel use remains a mystery. We have a long geographic history showing a much "warmer" equilibrium. I think anyone with basic scientific knowledge will admit this. This really makes it difficult to know how much we are actually warming vs. underlying unknown forces that Gavin et al. admitted to just last year.
Regardless of all the above, we are being told that it's not necessarily the warming, but the speed of warming that is catastrophic. It may be warming at warp speed or not. The real world data all tells me one thing: Human flourishing is at a peak and human suffering is at it's trough RIGHT NOW compared to all recorded human history. It is a heavy burden of proof for you, Andrew and others to convince me--a medical doctor with almost 20 years of research regarding OUTCOMES of said warming, to your side. Because of all this, I'll remain firmly in the skeptical camp until I see otherwise. Thanks,
The study very literally says that it was warmer in the past because CO2 was higher, and that CO2 is the primary control knob of the Earth's climate.
Tar baby.
Yes, everything is human caused, even earthquakes? I venture to suggest that similar heat patterns occurred during the Minoan warming, the Roman warming and the Medieval warming. Were they human caused too? The question facing science is what causes these 800-year warming events? My studies are tedious and slow due to my day-job taking my time, but they show that the sun is probably not a perfect sphere and has slight bulges that MIGHT be caused by a combination of the sun's rotation and the orbits of the large masses in the solar system (especially Jupiter) over several billion years. However, the cyclicity identified to date does not correspond with the 800-year cyclicity of these warming events. So, my hypothesis remains speculative at present, much like the anthropogenic CO2 hypothesis is. Potentially valid but a long way from proven fact. It is important to be honest about these hypotheses.
"So, my hypothesis remains speculative at present, much like the anthropogenic CO2 hypothesis is. Potentially valid but a long way from proven fact."
I might be missing the joke, but proof is for formal logic and distilled spirits. Your hypothesis differs from anthropogenic CO2-driven global warming in a crucial way: yours is idiosyncratic, and has no empirical or peer support; while the latter is as close to verified as any geophysical theory can be, by both the consilience of empirical evidence over two centuries of advancing science, and the current overwhelming peer consensus for it. Not everyone has to agree, just an effective majority of US voters: AGW is more than sufficiently confirmed to justify collective intervention in the US energy market, to take the profit out of transferring fossil carbon to the atmosphere.
"It is important to be honest about these hypotheses."
On that much we agree! TBH: whatever your background, if you actually think your "hypothesis" is as well-supported as AGW is, you're afflicted with the Dunning-Kruger Effect. Science is first and foremost a way of trying hard not to fool yourself: "The first rule is you must not fool yourself, and you are the easiest person to fool" (Feynman). "Intersubjective verification", i.e. consensus among trained, disciplined, mutually skeptical peers, is as fundamental to the success of the centuries-long, open-ended, cross-cultural scientific enterprise as rigorous empiricism and strict reasoning are. Verifiable, useful knowledge can't be self-correcting or cumulative without peer consensus at every increment. Anyone who tells you "consensus isn't science" is trying to fool you. And if you doubt the consensus but think the error lies with it, not you, then you're willfully fooling yourself!
Unsupported claims and read-only iteration of obstructionist dog whistles will be ghosted. What else is there?
Yes, it's sad that the guy hallucinates that variability is due to bulges in the sun when it's obvious that tidal cycles have much to do with all the zero-sum changes.
https://pukite.substack.com/p/mean-sea-level-models
Zeke
I had trouble understanding this but I gather this is the monthly mean and hottest absolute value which really restricts it to deep summer only. Why not temperature departures from a base period to let in all months? Then I suspect a lot of winter months will be the hottest change.
Folks tend to focus on summer heat waves, so this is specifically about when annual (monthly) record maximum temperatures occur. But I agree that you could look at the highest monthly anomaly of the year, which would tend to highlight more winter months.
I also suggest that it is much better to use three month running means, as proxy seasons. One month can be dominated by a single synoptic event and seasons cut down on that noise a lot.
Kevin
So just to be clear Zeke. A monthly slice for each zone would produce 12 highest record temperatures (eg highest in Jan = 2010, highest in Feb = 1999, highest in Mar = 2023 etc). So of the 12 record breakers per zone, how did you conclude on which decade you'd show on the graph / atlas given the records may span several decades?
This is showing the year of the hottest absolute monthly TMax temperature on record for each grid cell. So its only one value per year.
Point taken on cherry-picking but it is quite remarkable just how variable weather is and that it all too easy to see outlier events in the present that actually aren’t outside of the historical range of extremes.
Hot days are obviously the clearest result of a warming planet but many of the other hazardous weather-associated extremes in precipitation, flooding, winds, cyclonic activity and drought aren’t in some new catastrophic regime that they often get painted as being in, agreed? I think of these phenomena as at most warming-enhanced instead. Enhancement that will, I concede, increase over the next 50 to 70 years or longer depending on how the energy transition and any climate interventions go.
Thanks for the concession. Your comment is perfectly reasonable, but it just means there's a crucial time dimension to the political issue. My own advocacy for collective decarbonization is motivated not by headline-grabbing weather events but by pejorative secular empirical trends, some of them demonstrably accelerating.
And while it may be "all too easy" to see outliers that actually aren't, daily highs in Lytton, BC for three days in 2021 were clearly outside any reasonable historical range (https://en.wikipedia.org/wiki/Lytton,_British_Columbia):
"During heat waves, Lytton is often the hottest spot in Canada despite its location north of 50°N in latitude. [Yet] In three consecutive days of June 2021, it broke the all-time record for Canada's highest temperature, ending at 49.6 °C (121.3 °F) on June 29. This is the *highest temperature ever recorded north of 45°N and higher than the all-time records for Europe and South America*. The next day (June 30), a wildfire swept through the valley, destroying the majority of the town."
My emphasis. Human terror and grief notwithstanding, if that doesn't counter the insufficient-sample objection, nothing will.
Also: Yes, the accumulation of global heat content is enhanced by fossil carbon emissions, and will continue at least until emissions cease. But, it's already taking a calculable toll in lives as well (https://www.nytimes.com/2025/07/09/climate/europe-heat-waves-deaths.html). I, for one, find that moderately "alarming". Gotta leave room at the top for "globally apocalyptic" when it's called for!
Assurer l'avenir demande des sacrifices.
Is there reliable data for Africa outside of South Africa that stretches that far back?
There is back 90 years (to ~1935). It gets a bit sparser before 1900: https://berkeleyearth.org/temperature-region/africa
Good analysis. Aside from highlighting the clear need for action to mitigate this rise, the rising temperature trends draw attention to the urgency of adaptation requirements. There is a significant shortfall in resilience to the level of change that's already baked into our future climate.
So not to counter the conclusions of this which I totally believe, but I think this chart might be exaggerate the effect in one way. The most recent decades will always have the most records as they eliminate records from previous decades. For instance, if you did this say only using data up the year 2000, the 1990 would also show a peak. The question would be how much lower would the peak be than more recent decades.
That’s not quite how the statistics work here. If the climate were stationary (with short term unforced variability) there would be a roughly equal likelihood of a record being set in each decade (at least for the 90 years where all cells shown have complete data).
But we know the climate is not stationary. Why impose a background that is not realistic? See:
https://www.science.org/doi/10.1126/science.adk3705
How much of this is underlying earth returning to equilibrium?
Thank you,
“How much of this is underlying earth returning to equilibrium?”
We would need to explain why temperature decided relatively abruptly to quite rapidly return to equilibrium about 50 years ago, after varying relatively little for the preceding couple of thousand years.
We would also need a separate explanation as to why the atmospheric changes that have occurred over the same period, and which have the physical properties to cause a change in radiative forcing, did not do so.
That seems rather a lot of ad hoc-ery to try to explain something that already has a much more satisfactory explanation.
Hi Kingston,
Don't you find it a little presumptuous to think that we can look back millions of years to see how quickly temperatures changed within a 50 year timespan with any sort of accuracy? Any casual observer is going to ask, "If your point is to show abruptly the temps have been changing in the past 50 years, you'd better be darn sure you're using the same instruments to measure the acceleration and velocity of temp changes 50 million years ago too so we're comparing apples to apples".
Additionally, THE BALL IS IN YOUR COURT TO PROVE THAT CURRENT SAID "ABRUPT WARMING" IS ACTUALLY CAUSING CATASTROPHIC OUTCOMES. As a medical doctor with almost 20 years studying human health outcomes from the "climate change catastrophe", I find none. In fact, again, we are currently living in the best conditions ever recorded in human history. There is a distinct POSITIVE CORRELATION regarding warming and human flourishing. You carry a very heavy load to convince any of us that this "abrupt change" is not only not beneficial, but actually detrimental.
Scott,
“ Additionally, THE BALL IS IN YOUR COURT TO PROVE THAT CURRENT SAID "ABRUPT WARMING" IS ACTUALLY CAUSING CATASTROPHIC OUTCOMES”
Well, for a start, if we are discussing the cause of warming (and I thought we were), then obviously I am under no obligation to “prove” anything about a different subject altogether.
But as it happens, I am not greatly surprised that we don’t seem to be observing “catastrophic outcomes” in 2025, because I wasn’t aware that any such predictions were ever made. Of course, it doesn’t help that “catastrophe” is a non-scientific, highly subjective term.
Furthermore, while I completely agree that things have gotten much better for humans in recent times, I think it is rather questionable to attribute it to warming rather than advances in knowledge, technology and health.
"I am not greatly surprised that we don’t seem to be observing “catastrophic outcomes” in 2025"
I think you're "winning" the "debate" with Scott, and your understanding is authoritative. But the immediate argument is about the definition of "catastrophe". Clearly it's in the eyes of the beholder, not intersubjectively verifiable! Again, I ask whether attributable victims of the current abrupt warming are allowed input.
For example, a minimum estimate of 16,500 more people died in European heat waves this summer, 2025, than would have if not for the century-and-a-half long trend of GMST above pre-industrial, according to a peer-reviewed report published by the Grantham Institute of Imperial College (https://spiral.imperial.ac.uk/server/api/core/bitstreams/4d5b1a8a-c5ed-47fd-894c-f05ae31ae69d/content).
The report employs rapid-attribution methods, which pseudoskeptics dismiss as hand-waving. Scientifically metaliterate readers have a more nuanced view. The attributable victims no longer have an opinion. Their families presumably do, however. Again, must their numbers reach some threshold value before we'll all agree to "catastrophic"?
Scott,
“ Don't you find it a little presumptuous to think that we can look back millions of years to see how quickly temperatures changed within a 50 year timespan with any sort of accuracy?”
I asked you to consider why temperatures only started shooting up recently, after varying little for thousands (not millions) of years. If you are now suggesting that temperature variations similar to the last 50 years have been going on for thousands of years but the reconstructions are not sufficiently accurate to detect them, then obviously you are undermining your original thesis that the recent warming is simply a return to equilibrium with past higher temperatures.
But as it happens, the temperature reconstructions of the last few thousand years do seem to have the necessary resolution to rule this out. Temperature swings similar to recently (~1°C in 50 years) would appear to be well outside the error bars in those reconstructions.
The next problem is that, as I mentioned, there is a credible explanation for the recent warming (anthropogenic greenhouse forcing) but nothing comparable is known to have been going on over the last few thousand years. So you now have to come up with a new, currently unknown mechanism to explain changes that are not actually observed in temperature reconstructions.
See what I mean about the amount of ad hoc-ery involved?
Thanks Kingston. Freely extending your ineluctable, Occam's-Razor based objections: AFAICT, any proposal for an intrinsic, long-term equilibrium to which global heat content is returning, is religiously motivated (e.g. https://cornwallalliance.org/evangelical-declaration-on-global-warming). As you're aware, more pragmatic denialists love to tell us "climate is always changing!11!" "We", i.e. climate realists, know the latter is true inside the bounds published last year in *Science*: for the last 485 million years, within confidence limits, GMST has ranged from 11° to 36°C. And we know that throughout that range, GMST has always changed on geologic time scales, for known, or at least scientifically supported, geophysical reasons.
Sadly, we also know there's no enforceable or even existential requirement for denialists to be rational, so they're free (subject to forum moderation) as well: free, that is, to entertain both "climate has always changed" and "climate is returning to an [indeterminate] equilibrium" zombie obstructionist memes simultaneously. We, OTOH, know that the current GMST trend of >0.2°C/decade is unprecedented in recorded human history, wholly anthropogenic, and already causing casualties in excess of a preindustrial, quasi-stable climate state. I, for one, am as certain as I need to be that no magical indwelling equilibrium or teleological benevolence is going to intervene before the end of my "natural" [they'll take my Medicare from my cold, dead hands -MA] life.
Scott has long declared his determination not to be "terrified" by climate science, even though he's made an own-goal by linking to that *Science* article. "For the lurker" (h/t NSAlito), then, from the "Structured Abstract:
"Here, we present PhanDA, a reconstruction of GMST over the past 485 million years, generated by statistically integrating proxy data with climate model simulations. PhanDA exhibits a large range of GMST, spanning 11° to 36°C...
"...We find that Earth’s temperature has varied more dynamically than previously thought and that greenhouse climates were very warm. CO2 is the dominant driver of Phanerozoic climate, emphasizing the importance of this greenhouse gas in shaping Earth history."
OK. In the 200 years of advancing science since Fourier's proposal** of the greenhouse*** effect from planetary heat budget calculations, generations of trained, competitive, mutually-disciplined scientists have come far in their understanding of the forces determining Earth's climate and its changes over 485 my. There are cyclic astronomical partial drivers on 10, 20 and 100-ky scales, but longer or shorter periods don't emerge statistically from random variation around secular trends over random intervals, and no genuinely periodic forces can be detected. The burden is on contrary claimants to get past peer-review.
For newcomers to the history of climate science, I strongly recommend Dr. Weart's book "The Discovery of Global Warming". My brother, with a PhD in Economics, said it brought him up to speed efficiently! Meanwhile, the cited *Science* article helps to increase our confidence in the models used to project future GMST trends over a range of hypothetical CO2 concentration pathways.
That's my shot. Denialist tar babies will keep on JAQing off. Somebody else take the mallet. ["Block that metaphor!" -*The New Yorker*]
** Disclosure: ChatGPT suggested "proposal" instead of my choice, "induction". Like all my comments unless indicated, the rest is organic, if not intelligent 8^).
*** Not his word, and IMO a poor analogy, but I'm not the boss of colloquial English. Nobody is.
JFC, what equilbrium? Not across 485 million years!