Occasional Thoughts on Climate Change

[TheClimateChanger]

Funnily enough, the USCRN data largely supports my contention decades ago that the US climate record likely understates the change. If you accept USCRN as the gold standard, then, you must conclude nClimDiv [and the older USHCN] clearly understates warming in recent decades.

[bdgwx]

1 hour ago, TheClimateChanger said:

Funnily enough, the USCRN data largely supports my contention decades ago that the US climate record likely understates the change. If you accept USCRN as the gold standard, then, you must conclude nClimDiv [and the older USHCN] clearly understates warming in recent decades.

Exactly. The corrections applied to nClimDiv (USHCN) still aren't fully offsetting the biases and errors. 

[GaWx]

 Despite some including Grok AI insisting there’d need to be WAY more ocean floor vents than have been discovered for underwater seismic activity to significantly affect SSTs, the AGW denying JB today seems to ignore that per the the attached. He says he’s not aware of any possible explanation for the sharp cooling over the last year in much of the Atlantic other than a sharp reduction in mid ocean seismic activity:
 

You Can't Explain this kind of Drop with Man Made forcing

Wow. Look at the MDR drop off in Feb. 

Co2 does not explain that

This might tho

[rcostell]

This dataset stands on its own.  You can spin it, cherry pick "micro-areas", argue about its veracity or deny it exits. But in the real physical world- this dataset is corraborated by actual events and changes that one can visit, see and touch...that only this trend can explain.   Lets continue to keep a macro view, shall we? 

 

[GaWx]

2 hours ago, rcostell said:

This dataset stands on its own.  You can spin it, cherry pick "micro-areas", argue about its veracity or deny it exits. But in the real physical world- this dataset is corraborated by actual events and changes that one can visit, see and touch...that only this trend can explain.   Lets continue to keep a macro view, shall we? 

 

Per this in C:

-Biggest warmings in 1 yr (per eyeballing) (all >0.2)

1. 2022 to 23  0.30
2. 1976 to 77  0.27
3. 1887 to 88 and 1956 to 57 0.24
5. 1929 to 30  0.21

 

-Biggest warmings in 2 yr

1. 2022 to 24 0.39
2. 1887 to 89 0.29
3. 2014 to 16 0.28
4. 1971 to 73, 1996 to 98, and 1956 to 58 0.27
7. 1904 to 06 and 1929 to 31 0.26
 

[GaWx]

BOULDER’S WINDS AREN’T WHAT THEY USED TO BE

Extreme gusts in Boulder and Front Range appear to be diminishing

JUN 24, 2025 - BY DAVID HOSANSKY

Throughout the 1960s, 1970s, and 1980s, wind gusts routinely topped 120 miles per hour (mph), as measured at NSF NCAR’s Mesa Lab in the foothills above southwest Boulder. But the city’s extreme downslope winds have seemingly slackened in the last 30 years, with observed peak gusts rarely approaching 100 mph after 1995.

More research is needed to flesh out the reason for the decrease in peak gusts. But the paper suggests it may have to do with changes in atmospheric conditions. As global temperatures have become warmer, tropical storms are pumping more heat high in the atmosphere, affecting upper-level winds in the midlatitudes that could be changing the combination of atmospheric ingredients that produce  strong wind gusts during powerful downslope wind events.

“The difference in instrument location is part of the story, but the bigger picture probably has to do with changing conditions in the atmosphere,”

https://news.ucar.edu/133028/boulders-winds-arent-what-they-used-be

—————-

 Note that the year 1995 was stated as the cutoff point after which extreme gusts started to diminish. The +AMO/current active era/higher ACE for Atlantic tropical activity also started in 1995. Concurrently, the EPAC’s quieter ACE era started in 1995. Coincidence?

[chubbs]

On 7/4/2025 at 6:11 PM, GaWx said:

 Despite some including Grok AI insisting there’d need to be WAY more ocean floor vents than have been discovered for underwater seismic activity to significantly affect SSTs, the AGW denying JB today seems to ignore that per the the attached. He says he’s not aware of any possible explanation for the sharp cooling over the last year in much of the Atlantic other than a sharp reduction in mid ocean seismic activity:
 

You Can't Explain this kind of Drop with Man Made forcing

Wow. Look at the MDR drop off in Feb. 

Co2 does not explain that

This might tho

JB is just showing his lack of understanding of how the earth's climate works. Making a very simplistic argument that ignores the structure of the ocean. He needs to show that changes heat released at the bottom of the ocean made it all the way to the surface. The data is available from argo floats which get subsurface temperatures down to 2000m around the oceans. If seismic was driving our climate or having any significant impact at all we would know about it. 

I posted info previously which showed that the sun warms the ocean from the top down. Surface waters are less dense because they are warmer. In contrast the the waters at the bottom of the ocean where the vents are located are very cold and dense. That makes the ocean very stable. Ocean flow at the bottom of the ocean is horizontal in most locations. There is no way for changes in seismic activity to impact surface temperatures directly above the Atlantic vents. The only mixing between bottom and surface waters occurs in the arctic and antarctic where surface waters are cold enough to sink to the very bottom of the ocean. That's where the effect of any change in seismic heating would be felt at the surface. 

There is a much simpler explanation for the changes in the past year:  changes in surface wind speed. Since warming is top down, The waters just below the surface are always cooler. Higher winds cool the surface waters by promoting mixing. Light winds allow surface waters to warm. Wind driven mixing usually extends to roughly 100m. I showed a chart upthread which showed that surface winds in the area that cooled  are higher this year vs last.

[GaWx]

3 hours ago, chubbs said:

JB is just showing his lack of understanding of how the earth's climate works. Making a very simplistic argument that ignores the structure of the ocean. He needs to show that changes heat released at the bottom of the ocean made it all the way to the surface. The data is available from argo floats which get subsurface temperatures down to 2000m around the oceans. If seismic was driving our climate or having any significant impact at all we would know about it. 

I posted info previously which showed that the sun warms the ocean from the top down. Surface waters are less dense because they are warmer. In contrast the the waters at the bottom of the ocean where the vents are located are very cold and dense. That makes the ocean very stable. Ocean flow at the bottom of the ocean is horizontal in most locations. There is no way for changes in seismic activity to impact surface temperatures directly above the Atlantic vents. The only mixing between bottom and surface waters occurs in the arctic and antarctic where surface waters are cold enough to sink to the very bottom of the ocean. That's where the effect of any change in seismic heating would be felt at the surface. 

There is a much simpler explanation for the changes in the past year:  changes in surface wind speed. Since warming is top down, The waters just below the surface are always cooler. Higher winds cool the surface waters by promoting mixing. Light winds allow surface waters to warm. Wind driven mixing usually extends to roughly 100m. I showed a chart upthread which showed that surface winds in the area that cooled  are higher this year vs last.

 Thanks, Charlie!
 
 Yes, I recall you mentioning the surface winds being higher this year vs last thus resulting in cooling from upwelling. Regardless, I think it’s important to always expose JB when he spreads misinfo about underwater seismic being the main factor in ocean warming and now cooling.

 I don’t expose it and other stuff like this because I necessarily agree with it. However, sometimes I like being reminded of the true explanation. Also, I expose it to show how often it’s being spouted as well as to generate responses like yours to keep others informed who are just reading this stuff from JB for the first time of how far off JB is. Thus, I expect to repost more of this JB nonsense as he continually posts it in the near future.

[ChescoWx]

We are not alone in altered man made climate change

[chubbs]

19 hours ago, ChescoWx said:

We are not alone in altered man made climate change

You complain about being called a denier; but, your posts are the same old denier talking points or charts. Long debunked. Science moved on from this issue decades ago. 

[csnavywx]

On 7/3/2025 at 2:50 PM, donsutherland1 said:

Setting aside extreme maximum temperatures in the area most affected by the Dust Bowl, on a nationwide basis, such summers have already been matched or exceeded. Only 136 retains the top spot (in a tie).

Yep. We're basically there now and the probability of it striking in any given summer has risen sharply. Going through SSP5 8.5 runs can give a feel for how bad it could get in 10-30y. For instance, it has summers occasionally far exceeding anything in the 1930s and 2012 by the *middle of next decade*.

A few notes on that statement: While CO2 emissions are below 8.5 runs, radiative forcing and net energy imbalance is actually currently considerably *above* the 8.5 ensemble, mainly due to non-CO2 forcing being considerably above expectations -- and ECS/TCR might end up being on the hot side due to cloud feedback trends (detected by CERES). The most obvious brakes to this would be near term non-CO2 forcing slowdown, smoke aerosols (from extensive boreal burning -- seeing some of this already) and a weakening AMOC via differential hemispheric heating and a SMOC reversal (this too, may be in the early stages of happening). Regional trends are always a bear because transient climate responses can destructively or constructively interfere with the background trend and each other. A good example of this recently has been northern CONUS cooling in Feb-May due to a downstream response from rapid NPac cooling and cooling over the Corn Belt and adjacent areas from extensive evapotranspiration in Jun-Aug that has exchanged increased humidity for lower summer temps. These are transient responses -- and could and probably will unravel as the NHem temp response increases.

Perhaps more importantly, one striking feature in future runs is the ever-present ability of intra-seasonal and intra-annual forcing to temporarily overwhelm and unravel those transient responses and result in an explosive, high volatility move that seems to come from nowhere and create conditions that seem to detach completely from the existing probability curve. The damping is removed and, like a coiled spring, the "true PDF" is revealed. These will tend to cause the most damage because of their inherent year-to-year unpredictability.

A CMIP-6 run shows an example what that might look like (July 1936 and July 2012 are thrown in for good measure here):

 

 

Far more extreme events in general start to occur as the NHem circulation is disrupted by the permanent collapse of summer sea ice in the late '30s-40s and by the time we hit 2050 we open up "lights out" events where temps and precipitation could destroy the existing plant stock and most of those year's crops. Events so intense and long that we could see our first "year without a winter".

[rcostell]

34 minutes ago, chubbs said:

You complain about being called a denier; but, your posts are the same old denier talking points or charts. Long debunked. Science has moved on from this issue decades ago. 

Unfortunately, some people are too naive, stubborn, ignorant or deluded by others to recognize the preponderance of actual evidence and real world events that point to an oncoming conclusion.  Just how it is- they then hear their own echo chamber or are goaded by others. For the greater good- I think these people should be politely ignored by those not so afflicted.  See Isaac Cline - 1900 Galveston Hurricane. 

[Typhoon Tip]

5 hours ago, rcostell said:

Unfortunately, some people are too naive, stubborn, ignorant or deluded by others to recognize the preponderance of actual evidence and real world events that point to an oncoming conclusion.  Just how it is- they then hear their own echo chamber or are goaded by others. For the greater good- I think these people should be politely ignored by those not so afflicted.  See Isaac Cline - 1900 Galveston Hurricane. 

It really is quite simple…

Denial happens because it’s enabled

That’s it. Nothing else…

Now, if we want to get into what’s the enabling, that’s a fascinating effect of the human social condition functioning in a state of multigenerational abundance of choice and technological advantage

These provide recourse, whereas the morality of survival and virtuosity of learning are both being dimmed by the state of resource provision making populations less proactive -frankly making the bulk density of humanity, dumber and dumber

Amongst many other feedbacks, it’s definitely going to block people from seeing the damage that can be caused by an abstraction like an invisible slow moving apocalypse

 

 

 

[TheClimateChanger]

9 hours ago, ChescoWx said:

We are not alone in altered man made climate change

More misleading nonsense. Regarding the Tokyo data, you know something’s up when there’s a graph from Tony Heller’s wife limited to 1994-2021. You can pull up the raw data for Tokyo from JMA. There is, in fact, an inhomogeneity flagged in December 2014, consistent with the inflection point in this small subset of data. So the bias correction appears to be correct.

Moreover, the long-term trend is actually greatly reduced by the UHI correction. That’s why nothing before 1994 is shown there. Further, the two warmest years in the raw data are the last two years (even without correcting for the change that occurred in 2014). 2025 appears well on its way to approaching those highs.

Feel free to look for yourself: https://www.data.jma.go.jp/stats/data/en/index.html

[donsutherland1]

21 hours ago, Typhoon Tip said:

It really is quite simple…

Denial happens because it’s enabled

That’s it. Nothing else…

Now, if we want to get into what’s the enabling, that’s a fascinating effect of the human social condition functioning in a state of multigenerational abundance of choice and technological advantage

These provide recourse, whereas the morality of survival and virtuosity of learning are both being dimmed by the state of resource provision making populations less proactive -frankly making the bulk density of humanity, dumber and dumber

Amongst many other feedbacks, it’s definitely going to block people from seeing the damage that can be caused by an abstraction like an invisible slow moving apocalypse

 

 

 

In my view, the climate change apocalypse has already arrived. By “apocalypse,” I mean a profound transformation rather than total destruction, while acknowledging that at some point of warming, total destruction would become a viable scenario. The evidence is unmistakable to any objective observer: more frequent and extreme heatwaves, intensified precipitation events, accelerating aridification in the Desert Southwest and parts of Europe, and vast marine heatwaves disrupting ocean ecosystems. Scientists have laid out these findings clearly, coherently, and convincingly.

Science has not failed us. Instead, it is many of our leaders, both political and corporate, who have failed. Entrenched in a status quo from which they profit, they are prisoners of tunnel vision, unable or unwilling to see the full picture. They lack the courage to enact the changes needed to prevent this transformation from worsening. Instead, they display staggering creativity in inventing excuses for inaction. They pour vast energy into preserving an unsustainable and increasingly destructive system.

They claim that a world that does not burn fossil fuels is impossible. Yet history proves otherwise. Society has achieved far greater transformations within even tighter timelines. It harnessed atomic energy in a desperate race against the Nazis, sent humans to the Moon in less than a decade, and largely phased out CFCs to save the ozone layer in the 1990s. Society could have undertaken a similar transition away from fossil fuels. Moreover, the level of difficulty was less than that for atomic energy or the Apollo Project. This time, society had decades rather than years to act.

Ultimately, society chose another path, not because a transition was impossible, but because too many of its leaders lacked the courage to break free from the familiar, comfortable status quo.

[ChescoWx]

On 7/6/2025 at 1:26 PM, chubbs said:

You complain about being called a denier; but, your posts are the same old denier talking points or charts. Long debunked. Science moved on from this issue decades ago. 

LOL!! your "science" moved on the rest of us rooted in reality and actual data are not fooled.....

[ChescoWx]

2 hours ago, donsutherland1 said:

In my view, the climate change apocalypse has already arrived. By “apocalypse,” I mean a profound transformation rather than total destruction, while acknowledging that at some point of warming, total destruction would become a viable scenario. The evidence is unmistakable to any objective observer: more frequent and extreme heatwaves, intensified precipitation events, accelerating aridification in the Desert Southwest and parts of Europe, and vast marine heatwaves disrupting ocean ecosystems. Scientists have laid out these findings clearly, coherently, and convincingly.

Science has not failed us. Instead, it is many of our leaders, both political and corporate, who have failed. Entrenched in a status quo from which they profit, they are prisoners of tunnel vision, unable or unwilling to see the full picture. They lack the courage to enact the changes needed to prevent this transformation from worsening. Instead, they display staggering creativity in inventing excuses for inaction. They pour vast energy into preserving an unsustainable and increasingly destructive system.

They claim that a world that does not burn fossil fuels is impossible. Yet history proves otherwise. Society has achieved far greater transformations within even tighter timelines. It harnessed atomic energy in a desperate race against the Nazis, sent humans to the Moon in less than a decade, and largely phased out CFCs to save the ozone layer in the 1990s. Society could have undertaken a similar transition away from fossil fuels. Moreover, the level of difficulty was less than that for atomic energy or the Apollo Project. This time, society had decades rather than years to act.

Ultimately, society chose another path, not because a transition was impossible, but because too many of its leaders lacked the courage to break free from the familiar, comfortable status quo.

Don, it's the doomsday views and failed forecasts (Hello Al Gore) attribution of what is of course just weather that will continue to doom the climate alarmist agenda....all weather events that are occurring now have happened before. Until that changes there is little scientific reality ground to stand on!

[chubbs]

On 7/6/2025 at 10:35 AM, GaWx said:

 Thanks, Charlie!
 
 Yes, I recall you mentioning the surface winds being higher this year vs last thus resulting in cooling from upwelling. Regardless, I think it’s important to always expose JB when he spreads misinfo about underwater seismic being the main factor in ocean warming and now cooling.

 I don’t expose it and other stuff like this because I necessarily agree with it. However, sometimes I like being reminded of the true explanation. Also, I expose it to show how often it’s being spouted as well as to generate responses like yours to keep others informed who are just reading this stuff from JB for the first time of how far off JB is. Thus, I expect to repost more of this JB nonsense as he continually posts it in the near future.

Came across a paper on the North Atlantic marine heatwave of 2023. Light winds were the main cause not ocean transport. Supports the idea that this years Atlantic cooling is due to stronger winds.

https://www.nature.com/articles/s41586-025-08903-5

[GaWx]

16 minutes ago, chubbs said:

Came across a paper on the North Atlantic marine heatwave of 2023. Light winds were the main cause not ocean transport. Supports the idea that this years Atlantic cooling is due to stronger winds.

https://www.nature.com/articles/s41586-025-08903-5

Thanks, Charlie. 

 Another factor I’ve found is for shallow waters like those near the FL Keys: rainfall/clouds. The lack thereof lead to an extreme marine heatwave there that lead to badly bleached coral. When the clouds/rains returned, it cooled back quite a bit.

[donsutherland1]

Today's preliminary low temperature at Phoenix was 93°. if it holds, which is likely according to the guidance, that would tie the daily record set in 2021. Such exceptionally warm nights have exploded in number in recent years due to the combination of anthropogenic climate change and an escalating Urban Heat Island (UHI) Effect.

In the past, Phoenix's nights offered residents precious refuge from the day's heat. After long, scorching days under a relentless sun, the darkness would bring a faint coolness creeping back across the "Valley of the Sun."

Then in 1989, something extraordinary and unsettling happened. On July 20, the thermometer refused to drop below 93°. At the time, this was a rare anomaly, a single mark in the long record of desert nights that goes back to August 1895.

Throughout the 1990s, this eerie event remained nearly alone. Even as the City rapidly grew, there was just one other such night. Phoenix's residents could still count on most summer nights dipping into the 80s or sometimes the 70s, enough to sleep, to breathe, to recover.

But there was a dramatic shift toward hotter nights as the 21st Century commenced, particularly when the 30-year moving average summer temperature broke through 92.5°. During 2000-09, there were 14 such lows. The following decade was even worse, with 19 such lows during 2010-19. Then, there was a "breakout" from Phoenix's record book during the 2020s. Since 2020, amidst a sputtering Monsoon, there have been 46 such lows (today would be #47). That's more than for all of the period of record prior to 2020. Moreover, the last year without a 93° or above low was 2016.

Phoenix's 93° or Above Low Temperatures:

Phoenix's Mean Summer Low Temperatures and Trend (1980-2024):

 

[Typhoon Tip]

UHI working on top of AGW is meso scale harmonic feedback right there. It’s basically a synergistic heat example … scale notwithstanding 

[TheClimateChanger]

Morning thoughts:

 

[ChescoWx]

Climate Alarmists really are a tolerant bunch....fortunately we are starting to get more and more young meteorology professionals like Chris! Sadly, there are many older and younger professionals that Chris and I speak with in private....who share our concern about the damage being done by climate alarmists and zealots. Yet they feel forced to remain silent with their dissenting views that there is in fact no climate emergency at all. Fortunately the tide is turning and folks are coming back to common sense and calm around our always changing climate!

https://freebeacon.com/policy/im-a-young-meteorologist-who-questioned-the-idea-of-man-made-climate-change-the-climate-zealots-wanted-me-punished-silenced-and-expelled/

[donsutherland1]

10 hours ago, ChescoWx said:

Climate Alarmists really are a tolerant bunch....fortunately we are starting to get more and more young meteorology professionals like Chris! Sadly, there are many older and younger professionals that Chris and I speak with in private....who share our concern about the damage being done by climate alarmists and zealots. Yet they feel forced to remain silent with their dissenting views that there is in fact no climate emergency at all. Fortunately the tide is turning and folks are coming back to common sense and calm around our always changing climate!

https://freebeacon.com/policy/im-a-young-meteorologist-who-questioned-the-idea-of-man-made-climate-change-the-climate-zealots-wanted-me-punished-silenced-and-expelled/

As Martz often does, he builds plausible-sounding strawmen to evade the points that had been made. Zeff wrote:

Nuance is important: Zeff is referring to extreme rainfall events, increased likelihood of dangerous flooding, and explaining the basic physics (Clausius-Clapeyron equation) where a warmer atmosphere holds more moisture (about 7% for every 1°C increase in temperature). 

Now, look carefully at Martz's summary paragraph aimed at debunking Zeff:

I am a recent college graduate with a degree in meteorology. Zeff was replying to my post on social media, pointing out that he, and other climate activists, were ignoring basic scientific facts when they blamed man-made climate change for the tragic flooding in Texas. The truth is that the rainfall and flooding along the Guadalupe River were not historically unprecedented and had little, if anything, to do with climate change. Neither heavy rainfall nor river flooding has increased in the Texas Hill Country over the last six decades.

Notice how Martz subtly shifts the goal posts: He shifts the parameters to "historically unprecedented" rainfall and flooding. There is a difference between extreme (let's say top 1% of events) events and unprecedented ones. Notice also that Martz failed to try to shoot down the Clausius-Clapeyron equation. He couldn't.

So, the test concerns whether extreme rainfall amounts are increasing. For purposes of extreme events, I used the top 1% of events for the first-order stations for NWS San Antonio. Such stations have long periods of record. Their data is high quality. I used the 1951-1980 base period for the start of the comparison, because that is the NASA-GISS reference period. I used the most recent 30 years (1996-2025). The average rainfall for extreme (top 1%) of rainfall events is, in fact, increasing.

2-day periods were non overlapping. Thus, if January 1-2 and January 2-3 both appeared, the event with the lower 2-day amount was dropped, as a single event was involved.

Increases were also present for the shorter 1950-1959 and 2016-2025 ten-year periods. It's better statistical practice to use 30-year periods.

Now, notice further what Martz did:

1. He relied on EPA flood data that only goes to 2015. The data is obsolete for purposes of measuring a significant portion of the last 30-years, much less the last decade. Moreover, because it starts in 1965, it misses the timeframe to which Zeff had referred.

2. His rainfall chart concerned highest daily rainfall on an annual basis. But the flaws were as follows: a) he never listed the stations (key to reproducibility); b) he was measuring the top daily rainfall for a given year, which is bad methodology for measuring extreme events. Extreme events are not equally distributed. Some years contain clusters of them (e.g., 9 top 1% events for 1951-1980 for Del Rio occurred during 1969 while 1955 saw none; the Martz methodology would give equal weight to 1955 and 1969). Other years have none. Moreover, such events are not neatly limited to the daily period. They can occur over overlapping dates; c) his chart does not explain whether he took averages for the 21 COOP stations or used the highest value for the whole set. Given that extreme events can be local and discrete, averaging is bad methodology.

Because the data for floods is dated, I make no assessment on that matter. 

Finally, Martz makes a claim about "Texas Hill country." In fact, Kerr County that saw the extreme flood (2nd highest crest on the Guadalupe River) has no stations with rainfall data in the 1950s and 2010-present. A few stations have data in the 1940s. The Kerrville station only goes back to 1974.

Conclusion:

1. Martz did not debunk Zeff's observations

2. Martz did not provide data in a reproducible and transparent fashion

3. Martz used bad methodology for assessing extreme rainfall events

4. Martz made claims about a location for which data is sparse and cannot be used to assess Zeff's observations

5. Not specifically provided here, numerous attribution studies concerning excessive precipitation events have found linkages to climate change, consistent with what one would expect given the Clausius-Clapeyron equation. 

In the end, Martz's op-ed may win him points at the CFACT interest group where he works outside of the meteorology profession, but it wouldn't stand up to scientific rigor given the flaws related to transparency, reproducibility, and methodology. 

[chubbs]

From Brain Brettschneider. Moist east of the Rockies

[donsutherland1]

World Weather Attribution, along with Climate Central and the Red Cross Red Crescent Climate Centre, published a report on notable heatwaves during the May 1, 2024-May 1, 2025 period.

The report noted:

The year 2024 was, once again, the hottest year on record, surpassing the previous year (2023). It also marked the fi rst year in which global temperatures were clearly 1.5°C or more above the pre-industrial average for the whole year. Each month from January to June 2024 was the hottest ever recorded for that respective month, while the rest of the year was only marginally cooler than the record-breaking period of July to December 2023.

The year 2025 started with the hottest January ever recorded and the lowest amount of Arctic sea ice that a Northern Hemisphere winter has ever seen.

This is not a surprise or an accident — the causes are well known and the impacts are devastating. The continued burning of coal, oil, and gas has released and accumulated enough greenhouse gases to warm the planet by 1.3°C (over a 5-year average) — and by more than 1.5°C in 2024 alone — compared to pre-industrial times. In 2024, as in recent years, human-induced climate change drove more intense and frequent extreme weather events, with heat waves clearly and dramatically affected. One illustration of this is the March 2025 heat wave in Central Asia, which was up to 10°C warmer than it would have been without human-induced climate change.

Key findings:

• 4 billion people experienced at least 30 days of extreme heat. Extreme heat was defined as temperatures above the top 10% of readings during the 1991-2020 base period.
• In 195 countries, climate change had at least doubled the number of extremely hot days.

The report can be found here.

 

[TheClimateChanger]

On my mind for today:

 

[chubbs]

This is a good recent review article.

Anthropogenic intensification of short-duration rainfall extremes

https://hal.inrae.fr/hal-03838107v1/file/2021_Fowler_Nature reviews earth%26environment.pdf

 

[donsutherland1]

1 hour ago, chubbs said:

This is a good recent review article.

Anthropogenic intensification of short-duration rainfall extremes

https://hal.inrae.fr/hal-03838107v1/file/2021_Fowler_Nature reviews earth%26environment.pdf

 

That's why one should refer to the literature rather than social media tweets or opinion pieces from individuals who are not only outside the field, but working for organizations with interests that run counter to the science.

The Martz op-ed provided earlier in this thread offers a classic example of the flaws inherent in doing so. His primary interest was to claim that climate change is not leading to an increase in extreme rainfall events. He never appropriately addressed the actual question. The piece is deeply flawed, ranging from lack of transparency to bad methodology.

Six issues:

1. The piece revealed unfamiliarity with the literature, both papers and attribution studies. In fact, no literature was referenced.

2. The piece showed an absence of basic physical knowledge, namely when it comes to application of the Clausius-Clapeyron Equation that shows a direct relationship between increased temperature and increased capacity of the atmosphere to hold water vapor (approximately a 7% increase in water vapor capacity for every 1°C increase in temperatures).

3. Lack of awareness of recent very high Precipitable Water (PWAT) values in areas hit by excessive rainfalls (as would be predicted by the C-C equation).

4. Overgeneralization: He took 21 COOPs (unnamed) and suggested that they represent all of Texas. A more nuanced and specific description was needed.

5. The failure to name the COOPs deprives the exercise of transparency and makes reproducibility impossible.

6. Use of highest daily rainfall each year and reference to "unprecedented" events: An ability to identify the appropriate information for addressing research questions e.g., whether extreme rainfall events have increased, is essential to addressing those questions. There was a mismatch between what he looked at and the question involved. Extreme rainfall events are not equally distributed each year. Some years have clusters of such events. Others have none. The Martz approach gave all years equal weight and excluded numerous extreme rainfall events. His approach produced no useful information for addressing the question.

These flaws are fatal. If one is seeking to contradict the literature, the evidence needs to be particularly strong and specific to the research question(s) involved. To be credible, the findings need to be reproducible, therefore, transparency of methods is of paramount importance.