Climate Factors | Science Matters

Be Grateful for the Warming We Have

A reminder that we are presently in the icy end of the Holocene epoch comes in a CBC story Canada’s High Arctic was once a lush forest where unexpected animals roamed. Excerpts in italics with my bolds and added images.

Camels and beavers that evolved in ancient forests in the Far North
were perfectly adapted for our world today

Modern camels descend from giant High Arctic camels that lived in Canada’s North before the Ice Age. (Global Mechanic/Courtesy of Handful of Films)

By Niobe Thompson, director of Frozen in Time

When you think of the Canadian High Arctic today, visions of frozen tundra, icefields and polar bears probably come to mind. But rewind the clock a little over two million years to before the last ice age, and that Northern tundra was a lush and vibrant forest paradise. It was also home to some surprising animal life, including one large mammal we now associate with scorching deserts: camels.

In Frozen in Time, a documentary from The Nature of Things, paleobiologist Natalia Rybczynski describes how a head injury in 2011 changed the way she had to live. It also gave her time to think about many fossils she and her team at the Canadian Museum of Nature have uncovered of the animals that once roamed the Far North.

A remarkable discovery

The Pliocene Epoch, spanning from 2.5 to 5 million years ago, was the warm period before the last ice age began. The Pliocene was the last time Earth’s atmosphere contained the same concentration of carbon dioxide that we see today: over 400 parts per million.

At the time, temperatures in the High Arctic were also about 22 C higher than today, Rybczynski says in the documentary — a climate much like we see in modern boreal forest in Canada. As a result, the Arctic was covered in birch, larch, pine and even cedar trees, blanketing the landscape all the way to the northern shores of Ellesmere Island and Greenland.

These dense forests were home to many of the animals we now associate with the Pliocene, such as mammoths and mastodons, but also those found in modern boreal habitats: beavers, bears, geese, horses and caribou.

From 2006 to 2009, a research team led by the Canadian Museum of Nature discovered 30 camel fragments on Ellesmere Island in Nunavut. Scientists dated the remains to 3.5 million years, the mid-Pliocene Epoch, a global warm phase when the region was cloaked in boreal forest. Collagen fingerprinting, a cutting-edge science pioneered at the University of Manchester in England, confirmed that the bones belonged to a camelid.

And in 2013, a team of scientists led by Rybczynski announced a remarkable discovery. At the site of an ancient Pliocene river on Ellesmere Island called Fyles Leaf Beds, they uncovered fragments of a leg bone belonging to a 3.5-million-year-old camel. The find made headlines around the world and suggested that modern camels descended from a High Arctic ancestor.

Evolved in the Arctic, perfect for the desert

High Arctic camels were giant versions of modern camels, and they evolved in a forest world unlike any we know today. Because they lived close to the North Pole, the sun would disappear for nearly half the year, before shining down for nearly 24 hours a day during the polar summer.

Many of the features of the camel that help them survive in deserts today may have originated as adaptations to this punishing environment, Rybczynski says in Frozen in Time.

Their hump — a specialized fat deposit — would have helped them through long, cold winters. Camels have excellent night vision, handy when it is dark for almost half the year. And their wide feet that work so well in sand today would have been perfect in snow 3.5 million years ago.

The desert camel, the habits of beavers, bear hibernation, fall colours — all features of the natural world today that may have evolved in the weird Arctic forest world that came to an end with the encroaching glaciers of the last ice age.

“For me, it’s hard to stop imagining all those natural features of our environment, all passed down from a hotter past when forests could grow in the Arctic,” Rybczynski says in the documentary.

“In so many ways, the lost forests of the High Arctic were kind of like a Garden of Eden — the cradle of our boreal forest ecosystem today.”

OISST Updates: Ocean SST Cooling Confirmed

Posted on 15 Days Ago by Ron Clutz

The best context for understanding decadal temperature changes comes from the world’s sea surface temperatures (SST), for several reasons:

The ocean covers 71% of the globe and drives average temperatures;
SSTs have a constant water content, (unlike air temperatures), so give a better reading of heat content variations;
A major El Nino was the dominant climate feature in recent years.

Recently I posted on SST data from HadSST4 since the US shutdown stopped other SST sources. Now OISST is back online, so this report is based on data from OISST2.1. This dataset uses the same in situ sources as HadSST along with satellite indicators. Importantly, it produces daily anomalies from baseline period 1991-2020. The data is available at Climate Reanalyzer (here). Product guide is (here). The charts and analysis below is produced from the current data.

The Current Context

The chart below shows SST monthly anomalies as reported in OISST2.1 starting in 2015 through October 2025. A global cooling pattern is seen clearly in the Tropics since its peak in 2016, joined by NH and SH cycling downward since 2016, followed by rising temperatures in 2023 and 2024 and cooling in 2025.

Note that in 2015-2016 the Tropics and SH peaked in between two summer NH spikes. That pattern repeated in 2019-2020 with a lesser Tropics peak and SH bump, but with higher NH spikes. By end of 2020, cooler SSTs in all regions took the Global anomaly well below the mean for this period. A small warming was driven by NH summer peaks in 2021-22, but offset by cooling in SH and the tropics, By January 2023 the global anomaly was again below the mean.

Then in 2023-24 came an event resembling 2015-16 with a Tropical spike and two NH spikes alongside, all higher than 2015-16. There was also a coinciding rise in SH, and the Global anomaly was pulled up to 0.6°C in 2023, ~0.2° higher than the 2015 peak. Then NH started down autumn 2023, followed by Tropics and SH descending 2024 to the present. During nearly 2 years of cooling in SH and the Tropics, the Global anomaly came back down, led by Tropics cooling the last 22 months from its 0.9°C peak 2024/01 down to 0.26C in October this year. SH and NH also cooled Sept./Oct. pulling the Global anomaly down to 0.42C, just 0.1C above the average for this decadal period.

Comment:

The climatists have seized on this unusual warming as proof their Zero Carbon agenda is needed, without addressing how impossible it would be for CO2 warming the air to raise ocean temperatures. It is the ocean that warms the air, not the other way around. Recently Steven Koonin had this to say about the phonomenon confirmed in the graph above:

El Nino is a phenomenon in the climate system that happens once every four or five years. Heat builds up in the equatorial Pacific to the west of Indonesia and so on. Then when enough of it builds up it surges across the Pacific and changes the currents and the winds. As it surges toward South America it was discovered and named in the 19th century It iswell understood at this point that the phenomenon has nothing to do with CO2.

Now people talk about changes in that phenomena as a result of CO2 but it’s there in the climate system already and when it happens it influences weather all over the world. We feel it when it gets rainier in Southern California for example. So for the last 3 years we have been in the opposite of an El Nino, a La Nina, part of the reason people think the West Coast has been in drought.

It has now shifted in the last months to an El Nino condition that warms the globe and is thought to contribute to this Spike we have seen. But there are other contributions as well. One of the most surprising ones is that back in January of 2022 an enormous underwater volcano went off in Tonga and it put up a lot of water vapor into the upper atmosphere. It increased the upper atmosphere of water vapor by about 10 percent, and that’s a warming effect, and it may be that is contributing to why the spike is so high.

A longer view of SSTs

To enlarge, open image in new tab.

The graph above is noisy, but the density is needed to see the seasonal patterns in the oceanic fluctuations. Previous posts focused on the rise and fall of the last El Nino starting in 2015. This post adds a longer view, encompassing the significant 1998 El Nino and since. The color schemes are retained for Global, Tropics, NH and SH anomalies. Despite the longer time frame, I have kept the monthly data (rather than yearly averages) because of interesting shifts between January and July. 1995 is a reasonable (ENSO neutral) starting point prior to the first El Nino.

The sharp Tropical rise peaking in 1998 is dominant in the record, starting Jan. ’97 to pull up SSTs uniformly before returning to the same level Jan. ’99. There were strong cool periods before and after the 1998 El Nino event. Then SSTs in all regions returned to the mean in 2001-2.

SSTS fluctuate around the mean until 2007, when another, smaller ENSO event occurs. There is cooling 2007-8, a lower peak warming in 2009-10, following by cooling in 2011-12. Again SSTs are average 2013-14.

Now a different pattern appears. The Tropics cooled sharply to Jan 11, then rise steadily for 4 years to Jan 15, at which point the most recent major El Nino takes off. But this time in contrast to ’97-’99, the Northern Hemisphere produces peaks every summer pulling up the Global average. In fact, these NH peaks appear every July starting in 2003, growing stronger to produce 3 massive highs in 2014, 15 and 16. NH July 2017 was only slightly lower, and a fifth NH peak still lower in Sept. 2018.

The highest summer NH peaks came in 2019 and 2020, only this time the Tropics and SH were offsetting rather adding to the warming. (Note: these are high anomalies on top of the highest absolute temps in the NH.) Since 2014 SH has played a moderating role, offsetting the NH warming pulses. After September 2020 temps dropped off down until February 2021. In 2021-22 there were again summer NH spikes, but in 2022 moderated first by cooling Tropics and SH SSTs, then in October to January 2023 by deeper cooling in NH and Tropics.

Then in 2023 the Tropics flipped from below to well above average, while NH produced a summer peak extending into September higher than any previous year. Despite El Nino driving the Tropics January 2024 anomaly higher than 1998 and 2016 peaks, following months cooled in all regions, and the Tropics continued cooling in April, May and June along with SH dropping. After July and August NH warming again pulled the global anomaly higher, September through January 2025 resumed cooling in all regions. The descending sawtooth in all regions continued through Sept./Oct.

What to make of all this? The patterns suggest that in addition to El Ninos in the Pacific driving the Tropic SSTs, something else is going on in the NH. The obvious culprit is the North Atlantic, since I have seen this sort of pulsing before. After reading some papers by David Dilley, I confirmed his observation of Atlantic pulses into the Arctic every 8 to 10 years.

Contemporary AMO Observations

Through January 2023 I depended on the Kaplan AMO Index (not smoothed, not detrended) for N. Atlantic observations. But it is no longer being updated, and NOAA says they don’t know its future. So I find that ERSSTv5 AMO dataset has current data. It differs from Kaplan, which reported average absolute temps measured in N. Atlantic. “ERSST5 AMO follows Trenberth and Shea (2006) proposal to use the NA region EQ-60°N, 0°-80°W and subtract the global rise of SST 60°S-60°N to obtain a measure of the internal variability, arguing that the effect of external forcing on the North Atlantic should be similar to the effect on the other oceans.” So the values represent SST anomaly differences between the N. Atlantic and the Global ocean.

The chart above confirms what Kaplan also showed. As August is the hottest month for the N. Atlantic, its variability, high and low, drives the annual results for this basin. Note also the peaks in 2010, lows after 2014, and a rise in 2021. Then in 2023 the peak reached 1.4C before declining to 0.9 last month. An annual chart below is informative:

Note the difference between blue/green years, beige/brown, and purple/red years. 2010, 2021, 2022 all peaked strongly in August or September. 1998 and 2007 were mildly warm. 2016 and 2018 were matching or cooler than the global average. 2023 started out slightly warm, then rose steadily to an extraordinary peak in July. August to October were only slightly lower, but by December cooled by ~0.4C.

Then in 2024 the AMO anomaly started higher than any previous year, then leveled off for two months declining slightly into April. Remarkably, May showed an upward leap putting this on a higher track than 2023, and rising slightly higher in June. In July, August and September 2024 the anomaly declined, and despite a small rise in October, ended close to where it began. Note 2025 started much lower than the previous year and headed sharply downward, well below the previous two years, then since April through September aligning with 2010, with an upward bump in October 2025.

The pattern suggests the ocean may be demonstrating a stairstep pattern like that we have also seen in HadCRUT4.

The rose line is the average anomaly 1982-1996 inclusive, value -0.25. The orange line the average 1982-2025, value -0.014 also for the period 1997-2012. The red line is 2015-2025, value 0.32. As noted above, these rising stages are driven by the combined warming in the Tropics and NH, including both Pacific and Atlantic basins.

Curiosity: Solar Coincidence?

The news about our current solar cycle 25 is that the solar activity is hitting peak numbers now and higher than expected 1-2 years in the future. As livescience put it: Solar maximum could hit us harder and sooner than we thought. How dangerous will the sun’s chaotic peak be? Some charts from spaceweatherlive look familar to these sea surface temperature charts.

Summary

The oceans are driving the warming this century. SSTs took a step up with the 1998 El Nino and have stayed there with help from the North Atlantic, and more recently the Pacific northern “Blob.” The ocean surfaces are releasing a lot of energy, warming the air, but eventually will have a cooling effect. The decline after 1937 was rapid by comparison, so one wonders: How long can the oceans keep this up? And is the sun adding forcing to this process?

uss-pearl-harbor-deploys-global-drifter-buoys-in-pacific-ocean

USS Pearl Harbor deploys Global Drifter Buoys in Pacific Ocean

Glaciermania Strikes Again–2025 International Year of Glaciers

Posted on 16 Days Ago by Ron Clutz

UN is sounding alarms about glaciers, and media is amplifying as usual.

Climate emergency: 2025 declared international year of glaciers, UN News

Climate change is shrinking glaciers faster than ever, AP

Glaciers Are Melting Twice as Fast as Predicted and We’re Not Ready, Science News Today

1st glacier declared dead from climate change seen in before and after images, Live Science

Nearly 40% of the world’s glaciers are already doomed, CNN

Nearly Half of Earth’s Glaciers Are Already Doomed, Even Without Future Warming, SciTechDaily

World’s Melting Glaciers Threaten Food and Water Supply for 2 Billion People, Carbon Brief

Glaciers on the Brink: UN Calls for Bold Action, Climate Fact Checks

This short video puts this alarm into perspective. Additional detail is provided by Dr. John Happs in his article Glaciers And Ice Sheets: Here Today And Here Tomorrow. Dr. Happs comments on many glaciers around the world, this post has only some excerpts in italics with my bolds and added images.

How often do the climate alarmists tell us that few glaciers still exist because of (imaginary) global warming and those that remain are rapidly melting away? Not surprisingly, the alarmists, particularly those from the media and vested interest groups, always point to the Intergovernmental Panel on Climate Change (IPCC) computer model projections, referring to one in particular–the Representative Concentration Pathway (RCP8.5.)

Even the political/ideological IPCC has sensibly branded RCP8.5 as “Highly Unlikely”

So, what are the glacier numbers?

There are more than 200,000 alpine/valley (land-based) glaciers and many others stemming from the ice sheets of Antarctica and Greenland.

Glaciers have advanced, retreated and halted many times over the last 400,000 years being influenced not only by temperature but also by other factors, such as wind, precipitation, altitude, latitude, aspect, topography and slope angle.

Global temperature is often promoted, usually by naïve climate alarmists, as the only important input into glacier formation, growth and retreat yet, in very dry parts of Antarctica, where low temperatures are seemingly ideal for glacier growth, the small amount of net annual precipitation results in glaciers growing very slowly, or even diminishing in size.

Glaciers can also be influenced by sublimation or the transition of a substance directly from the solid to the gas phase. Glaciers can experience this process resulting in the “evaporation” of ice, exacerbated by wind action. Sublimation can be seen in the way that ice cubes left in the freezer will shrink over time.

More than 18,000 glaciers have been identified across 50 World Heritage sites but this represents less than 10% of the Earth’s glaciated area. The media, climate activists and vested interest groups like to argue that all glaciers are receding because global temperature is increasing. Not surprisingly, many glaciers have been retreating since we emerged from the Little Ice Age (1250-1850), a time when many farms and houses across Scandinavia were destroyed by advancing glaciers between the 14^th and 19^th centuries.

We might expect that glaciers and ice sheets would recede after the Little Ice Age yet we know that glaciers in many parts of the world are advancing, with glaciers growing in the Alps, North America, Patagonia, Antarctica, Alaska, the Himalayas, China, Iceland, Greenland, New Zealand, Norway, Antarctica and Greenland.

Where glaciers reach the sea, the media, and some tour guides, like to promote the dramatic calving-glacier image as pointing to (imaginary) global warming but fail to point out (perhaps they don’t know) that a calving glacier is the sign of an advancing inland glacier and certainly not one that is about to disappear.

In his silly, but influential, 2005 movie “An Inconvenient Truth” Al Gore said:

“Within the decade, there will be no more snows of Kilimanjaro.”

Mount Kilimanjaro is still covered in snow. See False Alarm over the Retreat of the Himalayan Glaciers

“The speed and consequences of Himalayan glacial retreat have been grossly exaggerated by the media and environmental activists.”

A significant proportion of Himalayan glaciers are advancing. In fact, 58% of glaciers examined in the westerly Karakoram range, a chain of snowy peaks along the border of India, Pakistan and China, were stable or advancing with annual snowfall increasing. A study of Himalayan glaciers, published in the American Meteorological Society’s Journal of Climate reported that cooler summers are failing to melt winter snows, which are themselves becoming more frequent, resulting in advancing glaciers. Source: Live Science

GLACIERS/ICE SHEETS IN ANTARCTICA

The Antarctic ice sheet is the world’s largest mass of ice covering around 14 million sq. km.

Ice sheets can be described as glaciers that cover very large areas and the most obvious examples are found in Greenland and Antarctica where around two-thirds of the Earth’s fresh water is stored.

Alarming reports that the Antarctic ice sheet is rapidly melting misrepresent the science of a very complex situation. Antarctica has been ice-covered for at least 30 million years. The ice sheet holds over 26 million gigatonnes of water (a gigatonne is a billion metric tons). If it were to melt completely, sea levels would rise 60 metres. Such a change is many millennia in the future, if it happens at all, although climate alarmists will always claim that such a response is just around the corner because of (imaginary) global warming.

Modest ice loss is normal in Antarctica. Each year in summer, more than 2,000 gigatonnes of ice is discharged in the form of melt and icebergs, while snowfall additions keep the ice mass in equilibrium.

Summary

So it is a familiar story. A complex naturally fluctuating situation, in this case glaciers, is abused by activists to claim support for their agenda. I have a lot of respect for glaciologists; it is a deep, complex subject, and the field work is incredibly challenging. And since “glacial” describes any process where any movement is imperceptible, I can understand their excitement over something happening all of a sudden.

But I do not applaud those pandering to the global warming/climate change crowd. They seem not to realize they debase their own field of study by making exaggerated claims and by “jumping the shark.”
Meanwhile real scientists are doing the heavy lifting and showing restraint and wisdom about the limitations of their knowledge.

Resources:

Redressing Antarctic Glacier Porn

Greenland Ice Varies, Don’t Panic 2023 Update

Climatists’ Childish Reading of Polar Ice

Figure 1. A comparison of presentations of satellite data capturing Greenland’s ice mass loss. The image on the right shows changes in Greenland’s ice mass relative to Greenland’s total ice mass. Sources: The data plotted in these graphs are from the Ice Sheet Mass Balance Inter-Comparison Exercise, a joint exercise by NASA and the European Space Agency.4 Graphs originally by Willis Eschenbach. Adapted and annotated by Anthony Watts.

October 2025 Ocean SST Cools to Mean

Posted on 20 Days Ago by Ron Clutz

The best context for understanding decadal temperature changes comes from the world’s sea surface temperatures (SST), for several reasons:

The ocean covers 71% of the globe and drives average temperatures;
SSTs have a constant water content, (unlike air temperatures), so give a better reading of heat content variations;
A major El Nino was the dominant climate feature in recent years.

Previously I used HadSST3 for these reports, but Hadley Centre has made HadSST4 the priority, and v.3 will no longer be updated. I’ve grown weary of waiting each month for HadSST4 updates, so the July and August reports were based on data from OISST2.1. This dataset uses the same in situ sources as HadSST along with satellite indicators. Now however, the US government is shut down and updates to climate datasets are likely to be delayed. Reminds of what hospitals do when their budgets are slashed: They close the Maternity Ward to get public attention.

So this October report is based again on HadSST 4, but with a twist. The data is slightly different in the new version, 4.2.0.0 replacing 4.1.1.0. Product page is here.

The Current Context

The chart below shows SST monthly anomalies as reported in HadSST 4.2 starting in 2015 through October 2025. A global cooling pattern is seen clearly in the Tropics since its peak in 2016, joined by NH and SH cycling downward since 2016, followed by rising temperatures in 2023 and 2024 and cooling in 2025.

Then in 2023-24 came an event resembling 2015-16 with a Tropical spike and two NH spikes alongside, all higher than 2015-16. There was also a coinciding rise in SH, and the Global anomaly was pulled up to 1.1°C in 2023, ~0.3° higher than the 2015 peak. Then NH started down autumn 2023, followed by Tropics and SH descending 2024 to the present. During 2 years of cooling in SH and the Tropics, the Global anomaly came back down, led by Tropics cooling from its 1.3°C peak 2024/01, down to 0.6C in September this year. Note the smaller peak in NH in July 2025 now declining along with SH and the Global anomaly cooler as well. In October the Global anomaly nearly matched the mean for this period

Comment:

A longer view of SSTs

To enlarge, open image in new tab.

Then in 2023 the Tropics flipped from below to well above average, while NH produced a summer peak extending into September higher than any previous year. Despite El Nino driving the Tropics January 2024 anomaly higher than 1998 and 2016 peaks, following months cooled in all regions, and the Tropics continued cooling in April, May and June along with SH dropping. After July and August NH warming again pulled the global anomaly higher, September through January 2025 resumed cooling in all regions, continuing February through April 2025, with little change in May,June and July despite upward bumps in NH. Now temps in all regions are cooling August and September 2025.

Contemporary AMO Observations

The pattern suggests the ocean may be demonstrating a stairstep pattern like that we have also seen in HadCRUT4.

The rose line is the average anomaly 1982-1996 inclusive, value 0.18. The orange line the average 1982-2025, value 0.40 also for the period 1997-2012. The red line is 2015-2025, value 0.68. As noted above, these rising stages are driven by the combined warming in the Tropics and NH, including both Pacific and Atlantic basins.

Curiosity: Solar Coincidence?

Summary

uss-pearl-harbor-deploys-global-drifter-buoys-in-pacific-ocean

USS Pearl Harbor deploys Global Drifter Buoys in Pacific Ocean

UAH Ocean Stays Cool, SH Land Warms, October 2025

Posted on 27 Days Ago by Ron Clutz

The post below updates the UAH record of air temperatures over land and ocean. Each month and year exposes again the growing disconnect between the real world and the Zero Carbon zealots. It is as though the anti-hydrocarbon band wagon hopes to drown out the data contradicting their justification for the Great Energy Transition. Yes, there was warming from an El Nino buildup coincidental with North Atlantic warming, but no basis to blame it on CO2.

As an overview consider how recent rapid cooling completely overcame the warming from the last 3 El Ninos (1998, 2010 and 2016). The UAH record shows that the effects of the last one were gone as of April 2021, again in November 2021, and in February and June 2022 At year end 2022 and continuing into 2023 global temp anomaly matched or went lower than average since 1995, an ENSO neutral year. (UAH baseline is now 1991-2020). Then there was an usual El Nino warming spike of uncertain cause, unrelated to steadily rising CO2, and now dropping steadily back toward normal values.

For reference I added an overlay of CO2 annual concentrations as measured at Mauna Loa. While temperatures fluctuated up and down ending flat, CO2 went up steadily by ~65 ppm, an 18% increase.

Furthermore, going back to previous warmings prior to the satellite record shows that the entire rise of 0.8C since 1947 is due to oceanic, not human activity.

gmt-warming-events

The animation is an update of a previous analysis from Dr. Murry Salby. These graphs use Hadcrut4 and include the 2016 El Nino warming event. The exhibit shows since 1947 GMT warmed by 0.8 C, from 13.9 to 14.7, as estimated by Hadcrut4. This resulted from three natural warming events involving ocean cycles. The most recent rise 2013-16 lifted temperatures by 0.2C. Previously the 1997-98 El Nino produced a plateau increase of 0.4C. Before that, a rise from 1977-81 added 0.2C to start the warming since 1947.

Importantly, the theory of human-caused global warming asserts that increasing CO2 in the atmosphere changes the baseline and causes systemic warming in our climate. On the contrary, all of the warming since 1947 was episodic, coming from three brief events associated with oceanic cycles. And in 2024 we saw an amazing episode with a temperature spike driven by ocean air warming in all regions, along with rising NH land temperatures, now dropping well below its peak.

Chris Schoeneveld has produced a similar graph to the animation above, with a temperature series combining HadCRUT4 and UAH6. H/T WUWT

October 2025 UAH Temps: Cool Ocean, Warm Land

With apologies to Paul Revere, this post is on the lookout for cooler weather with an eye on both the Land and the Sea. While you heard a lot about 2020-21 temperatures matching 2016 as the highest ever, that spin ignores how fast the cooling set in. The UAH data analyzed below shows that warming from the last El Nino had fully dissipated with chilly temperatures in all regions. After a warming blip in 2022, land and ocean temps dropped again with 2023 starting below the mean since 1995. Spring and Summer 2023 saw a series of warmings, continuing into 2024 peaking in April, then cooling off to the present.

UAH has updated their TLT (temperatures in lower troposphere) dataset for October 2025. Due to one satellite drifting more than can be corrected, the dataset has been recalibrated and retitled as version 6.1 Graphs here contain this updated 6.1 data. Posts on their reading of ocean air temps this month are ahead the update from HadSST4 or OISST2.1. I posted recently on SSTs September 2025 Ocean SST Cooling These posts have a separate graph of land air temps because the comparisons and contrasts are interesting as we contemplate possible cooling in coming months and years.

Sometimes air temps over land diverge from ocean air changes. In July 2024 all oceans were unchanged except for Tropical warming, while all land regions rose slightly. In August we saw a warming leap in SH land, slight Land cooling elsewhere, a dip in Tropical Ocean temp and slightly elsewhere. September showed a dramatic drop in SH land, overcome by a greater NH land increase. 2025 has shown a sharp contrast between land and sea, first with ocean air temps falling in January recovering in February. Now in September and October SH land temps have spiked while ocean temps showed litle change. As a result of larger ocean surface, Global temps remained cool.

Note: UAH has shifted their baseline from 1981-2010 to 1991-2020 beginning with January 2021. v6.1 data was recalibrated also starting with 2021. In the charts below, the trends and fluctuations remain the same but the anomaly values changed with the baseline reference shift.

Presently sea surface temperatures (SST) are the best available indicator of heat content gained or lost from earth’s climate system. Enthalpy is the thermodynamic term for total heat content in a system, and humidity differences in air parcels affect enthalpy. Measuring water temperature directly avoids distorted impressions from air measurements. In addition, ocean covers 71% of the planet surface and thus dominates surface temperature estimates. Eventually we will likely have reliable means of recording water temperatures at depth.

Recently, Dr. Ole Humlum reported from his research that air temperatures lag 2-3 months behind changes in SST. Thus cooling oceans portend cooling land air temperatures to follow. He also observed that changes in CO2 atmospheric concentrations lag behind SST by 11-12 months. This latter point is addressed in a previous post Who to Blame for Rising CO2?

After a change in priorities, updates are now exclusive to HadSST4. For comparison we can also look at lower troposphere temperatures (TLT) from UAHv6.1 which are now posted for October 2025. The temperature record is derived from microwave sounding units (MSU) on board satellites like the one pictured above. Recently there was a change in UAH processing of satellite drift corrections, including dropping one platform which can no longer be corrected. The graphs below are taken from the revised and current dataset.

The UAH dataset includes temperature results for air above the oceans, and thus should be most comparable to the SSTs. There is the additional feature that ocean air temps avoid Urban Heat Islands (UHI). The graph below shows monthly anomalies for ocean air temps since January 2015.

In 2021-22, SH and NH showed spikes up and down while the Tropics cooled dramatically, with some ups and downs, but hitting a new low in January 2023. At that point all regions were more or less in negative territory.

After sharp cooling everywhere in January 2023, there was a remarkable spiking of Tropical ocean temps from -0.5C up to + 1.2C in January 2024. The rise was matched by other regions in 2024, such that the Global anomaly peaked at 0.86C in April. Since then all regions have cooled down sharply to a low of 0.27C in January. In February 2025, SH rose from 0.1C to 0.4C pulling the Global ocean air anomaly up to 0.47C, where it stayed in March and April. In May drops in NH and Tropics pulled the air temps over oceans down despite an uptick in SH. At 0.43C, ocean air temps were similar to May 2020, albeit with higher SH anomalies. Now in September/October Global ocean temps are little changed with Tropics dropping again along with NH declining slightly..

Land Air Temperatures Tracking in Seesaw Pattern

We sometimes overlook that in climate temperature records, while the oceans are measured directly with SSTs, land temps are measured only indirectly. The land temperature records at surface stations sample air temps at 2 meters above ground. UAH gives tlt anomalies for air over land separately from ocean air temps. The graph updated for October is below.

Here we have fresh evidence of the greater volatility of the Land temperatures, along with extraordinary departures by SH land. The seesaw pattern in Land temps is similar to ocean temps 2021-22, except that SH is the outlier, hitting bottom in January 2023. Then exceptionally SH goes from -0.6C up to 1.4C in September 2023 and 1.8C in August 2024, with a large drop in between. In November, SH and the Tropics pulled the Global Land anomaly further down despite a bump in NH land temps. February showed a sharp drop in NH land air temps from 1.07C down to 0.56C, pulling the Global land anomaly downward from 0.9C to 0.6C. Some ups and downs followed with returns close to February values in August. Now in October we see a remarkable spike in SH land temps, supported by NH and Tropics in September.

The Bigger Picture UAH Global Since 1980

The chart shows monthly Global Land and Ocean anomalies starting 01/1980 to present. The average monthly anomaly is -0.0, 2for this period of more than four decades. The graph shows the 1998 El Nino after which the mean resumed, and again after the smaller 2010 event. The 2016 El Nino matched 1998 peak and in addition NH after effects lasted longer, followed by the NH warming 2019-20. An upward bump in 2021 was reversed with temps having returned close to the mean as of 2/2022. March and April brought warmer Global temps, later reversed

With the sharp drops in Nov., Dec. and January 2023 temps, there was no increase over 1980. Then in 2023 the buildup to the October/November peak exceeded the sharp April peak of the El Nino 1998 event. It also surpassed the February peak in 2016. In 2024 March and April took the Global anomaly to a new peak of 0.94C. The cool down started with May dropping to 0.9C, and in June a further decline to 0.8C. October went down to 0.7C, November and December dropped to 0.6C.In August Global Land and Ocean went down to 0.39C, then rose slightly to 0.53 in October.

The graph reminds of another chart showing the abrupt ejection of humid air from Hunga Tonga eruption.

TLTs include mixing above the oceans and probably some influence from nearby more volatile land temps. Clearly NH and Global land temps have been dropping in a seesaw pattern, nearly 1C lower than the 2016 peak. Since the ocean has 1000 times the heat capacity as the atmosphere, that cooling is a significant driving force. TLT measures started the recent cooling later than SSTs from HadSST4, but are now showing the same pattern. Despite the three El Ninos, their warming had not persisted prior to 2023, and without them it would probably have cooled since 1995. Of course, the future has not yet been written.

Placing Melissa in History

Posted on November 2 by Ron Clutz

Climatic media has fallen in love with Melissa, many of them blaming “climate change”, i.e. CO2 for her strength and destructive power. No surprise that Imperial College London (who foisted its covid pandemic models upon us) reports that its IRIS model confirms a “rapid attribution” claim. No doubt there will be more such yada yada at Belem COP to stir up the faithful.

For the rest of us, let’s remember the saying attributed to George Santayana: “Those who cannot remember the past are condemned to repeat it.” For example, Melissa belongs to a class of stong Atlantic hurricanes going back almost a century. Here’s a table of them along with peak sustained winds and the CO2 levels at the time.

		Peak Wind	CO2 Level
Hurricane	Year	mph	ppm
“Cuba”	1932	175	308
“Labor Day”	1935	185	310
Janet	1955	175	314
Camille	1969	175	325
Anita	1977	175	334
David	1979	175	337
Allen	1980	190	339
Gilbert	1988	185	352
Andrew	1992	175	356
Mitch	1998	180	367
Wilma	2005	185	380
Rita	2005	180	380
Katrina	2005	175	380
Dean	2007	175	384
Felix	2007	175	384
Irma	2017	180	407
Maria	2017	175	407
Dorian	2019	185	411
Milton	2024	180	425
Melissa	2025	185	428

Note that all twenty hurricanes had winds ranging between 175 to 190 mph, going back to 1932. Meanwhile CO2 has increased from 308 ppm to 428 (2025 ytd). Note also the absence of such storms in the decade 2007 to 2017 despite CO2 adding 23 ppm in that period. The correlation between high wind speeds and CO2 concentrations is an insignificant 0.18.

Then there is the Global Accumulated Cyclone Energy (ACE) report that includes the effects of both minor and major storms, combining strength and frequency.

I added an overlay of CO2 to illustrate how unlikely is a link between CO2 and storms. Finally from Roger Pielke Jr. a chart showing ACE strength per hurricane:

The charts show that 16 is the average ACE per hurricane, in North Atlantic since 1900 and Globally since 1980. The trend is not upward, and in North Atlantic appears currently lower than the past.

IPCC Global Warming Claims Not Only Wrong, But Impossible

Posted on October 27 by Ron Clutz

Climate as heat engine. A heat engine produces mechanical energy in the form of work W by absorbing an amount of heat Qin from a hot reservoir (the source) and depositing a smaller amount Qout into a cold reservoir (the sink). (a) An ideal Carnot heat engine does the job with the maximum possible efficiency. (b) Real heat engines are irreversible, and some work is lost via irreversible entropy production TδS. (c) For the climate system, the ultimate source is the Sun, with outer space acting as the sink. The work is performed internally and produces winds and ocean currents. As a result, Qin = Qout.

Ad Huijser recently published a paper explaining why IPCC claims about global warming are contradicted by observations of our Earth thermal system including a number of internal and external subsytems. The title Global Warming and the “impossible” Radiation Imbalance links to the pdf. This post is a synopsis to present the elements of his research findings, based on the rich detail, math and references found in the document. Excerpts in italics with my bolds and added images. H/T Kenneth Richard and No Tricks Zone.

Abstract

Any perturbation in the radiative balance at the top of the atmosphere (TOA) that induces a net energy flux into- or out of Earth’s thermal system will result in a surface temperature response until a new equilibrium is reached. According to the Anthropogenic Global Warming (AGW) hypothesis which attributes global warming solely to rising concentrations of Greenhouse gases (GHGs), the observed increase in Earth’s radiative imbalance is entirely driven by anthropogenic GHG-emissions.

However, a comparison of the observed TOA radiation imbalance with the assumed GHG forcing trend reveals that the latter is insufficient to account for the former. This discrepancy persists even when using the relatively high radiative forcing values for CO2 adopted by the Intergovernmental Panel on Climate Change (IPCC), thereby challenging the validity of attributing recent global warming exclusively to human-caused GHG emissions.

In this paper, Earth’s climate system is analyzed as a subsystem of the broader Earth Thermal System, allowing for the application of a “virtual balance” approach to distinguish between anthropogenic and other, natural contributions to global warming. Satellite-based TOA radiation data from the CERES program (since 2000), in conjunction with Ocean Heat Content (OHC) data from the ARGO float program (since 2004), indicate that natural forcings must also play a significant role. Specifically, the observed warming aligns with the net increase in incoming shortwave solar radiation (SWIN), likely due to changes in cloud cover and surface albedo. Arguments suggesting that the SWIN trend is merely a feedback response to GHG-induced warming are shown to be quantitatively insufficient.

This analysis concludes that approximately two-thirds of the observed global warming must be attributed to natural factors that increase incoming solar radiation, with only one-third attributable to rising GHG-concentrations. Taken together, these findings imply a much lower climate sensitivity than suggested by IPCC-endorsed Global Circulation Models (GCMs).

Introduction

On a global scale and over longer periods of time, the average surface temperature of our climate system reacts similarly to that of a thermal system such as a pot of water on a stove: when the incoming heat is steady and below boiling, the system stabilizes when the heat loss (via radiation and convection) equals the input. Analogously, Earth’s surface-atmosphere interface is the main absorber and emitter of heat. Reducing the “flame” (solar input) leads to cooling, regardless of the total heat already stored in the system. The system’s average temperature will drop as well, as soon as the heating stops. So, no sign of any “warming in the pipeline” for such a simple system.

The two transport mechanisms, air and ocean, operate on different timescales. Air has a low specific heat capacity, but high wind speeds make it a fast medium for heat transfer. Oceans, by contrast, have a high specific heat capacity but move more slowly. The Atlantic Meridional Overturning Circulation (AMOC) with the well-known Gulf Stream carrying warm water from south to north, can reach speeds up to about 3 m/s. But its warm current remains largely confined to surface layers due to limited solar radiation penetration and gravity-induced stratification. With a path-lengths of up to 8,000 km and an average speed of 1.5 m/s, ocean heat takes approximately 2 months to travel from the Gulf of Mexico to the Arctic. This is comparable to the 1 to 2 months delay between solar input and temperature response in the annual cycle, suggesting that oceanic heat transport is part of the climate system’s normal operation. Climate adaptation times from anthropogenic influences are estimated at 3 to 5 years. If “warming in the pipeline” exists, it must be buried in the much colder, deeper ocean layers.

ARGO float data since 2004 show substantial annual increases in Ocean Heat Content (OHC), sometimes expressed in mind-boggling terms such as 10²² joules per year (see Fig.1). While this may sound alarming [1,2], when converted to flux, it represents less than 1 W/m², a mere 0.6% of the average 160 W/m² of absorbed solar energy at the surface. All the rest is via evaporation, convection and ultimately by radiation sent back to space after globally being redistributed by wind and currents.

Fig. 1. Ocean Heat Content (OHC) anomaly from 0–2000 meters over time, shown as 3-month and annual moving averages (CMAA), along with their time derivatives. Notable are the relatively large variations, likely reflecting the influence of El Niño events. The average radiative imbalance at the top of the atmosphere (TOA), estimated at 0.85 W/m², corresponds approximately to the midpoint of the time series (around 2015). Data: https://www.ncei.noaa.gov/access/global-ocean-heat-content/basin_heat_data.html [7].

This raises the question: Why would extra GHGs that have only a limited effect on the 99.4% of the outgoing flux, have affected this 0.6% residue during a couple of decennia in such a way that we should be scared about all that “warming in the pipeline” as Hansen et al. [2] are warning us for? In the following sections, we examine data showing that observed trends in the radiation imbalance and OHC are better explained by the internal dynamics of the Earth’s thermal system and natural forcings such as from increasing solar radiation, rather than solely by GHG emissions.

Estimating our climate’s thermal capacity CCL

The rather fast responses of our climate indicates that the thermal capacity of our climate must be much less than the capacity of the entire Earth thermal system. This climate heat capacity CCL depends on how sunlight is being absorbed, how that heat is transferred to the atmosphere and which part of it is being stored in either land or ocean.

At continental land-area, sunlight is absorbed only at the very surface where the generated heat is also in direct contact with the atmosphere. Seasonal temperature variations don’t penetrate more than 1 to 2 meters deep in average and as a consequence, storage of heat is relatively small. Sunlight can penetrate pure water to several hundred meters deep, but in practice, penetration in the oceans is limited by scattering and absorption of organic and inorganic material. A good indication is the depth of the euphotic zone where algae and phytoplankton live, which need light to grow. In clear tropical waters where most of the sunlight hits our planet, this zone is 80 to 100 m deep [12].

Another important factor in our climate’s heat capacity is how this ocean layer of absorbed heat is in contact with the atmosphere. Tides, wind, waves and convection continuously mix the top layer of our oceans, by which heat is easily exchanged with the atmosphere. This mixed-layer is typically in the order of 25 – 100 m, dependent on season, latitude and on the definition of “well mixed” [13]. Below this ~100 m thick top-layer, where hardly any light is being absorbed and the mixing process has stopped, ocean temperatures drop quickly with depth. As the oceans’ vertical temperature gradient at that depth doesn’t support conductive nor convective heat flows going upward, climate processes at the surface will thus become isolated from the rest of the Earth’ thermal system.

Figure 4 with the Change in Ocean Heat Content vs. Depth over the period 2004 – 2020 obtained via the ARGO-floats [6,14], offers a good indication for the average climate capacity CCL. It shows the top layer with a high surface temperature change according to the observed global warming rate of about 0.015 K/year, and a steep cut off at about 100 m depth in line with the explanation above. Below the top layer, temperature effects are small and difficult to interpret, probably due to averaging over all kinds of temperature/depth profiles in the various oceans ranging from Tropical- to Polar regions.

In case of a “perfect” equilibrium (N = 0, dTS/dt = 0), all of the absorbed sunlight up to about 100 m deep, has to leave on the ocean-atmosphere interface again. However, deep oceans are still very cold with a stable, negative temperature gradient towards the bottom. This gradient will anyhow push some of the absorbed heat downwards. Therefore, even at a climate equilibrium with dTS/dt= 0, we will observe N > 0. With the large heat capacity of the total ocean volume, that situation will not change easily, as it takes about 500 years with today’s N ≈ +1 W/m2 to raise its average temperature just 1°C.

The Earth’s climate system can thus be regarded as a subset of the total Earth’s thermal system (ETS) responding to different relaxation times. The climate relaxes to a new equilibrium within 3–5 years, while the deeper oceans operate on multidecadal or even longer timescales, related to their respective thermal capacities C for the ETS, and CCL for the climate system.

The (near) “steady state” character of current climate change

Despite the ongoing changes in climate, the current state can be considered a “near” steady-state. The GHG forcing trend has been pretty constant for decades. Other forcings, primarily in the SW channel, are also likely to change slowly and can be approximated as having constant trends over decadal timescales. Similarly, despite yearly fluctuations, the surface temperature trend has remained fairly stable since 2000.

This analysis strengthens the conclusion that the increase in both N(t) and N0(t) are not a direct consequence of greenhouse gas emissions, but rather of enhanced forcing in the SW-channel.

The preceding analysis highlights how the IPCC’s assumptions diverge significantly from observed reality. While the IPCC model components may collectively reproduce the observed warming trend, they fail to individually align with key observational data, in particular the Ocean Heat Content.

Figure 6 also illustrates that changes in cloudiness are more pronounced on the Northern Hemisphere, especially at mid-latitudes and over Western Europe. For example, the Dutch KNMI weather-station at Cabauw (51.87°N, 4.93oE), where all ground-level radiation components are monitored every 10 minutes, recorded an increase in solar radiation of almost +0.5 W/m²/year since 2000 [26]. Applying the 0.43 net-CRE factor (conservative for this latitude), we estimate a local forcing trend dFSW/dt ≈ 0.2 W/m²/year. This is an order of magnitude larger than the GHG forcing (0.019–0.037 W/m²/year). Even with the IPCC values, GHGs can just account for about 16% of the warming at this station. The average temperature trend for this rural station located in a polder largely covered by grassland, is with ~ +0.043 K/year almost 3x the global average. This, nor the other trends mentioned above can be adequately explained by the IPCC’s GHG-only model.

The IPCC places strong emphasis on the role of climate feedbacks in amplifying the warming effect of greenhouse gases (GHGs) [8]. These feedbacks are considered secondary consequences of Anthropogenic Global Warming, driven by the initial temperature increase from GHGs. Among them, Water-Vapor feedback is the most significant. A warmer atmosphere holds more water vapor (approximately +7%/K) and since water vapor is a potent GHG, even a small warming from CO2 can amplify itself through enhanced evaporation.

Other feedbacks recognized by the IPCC include Lapse Rate, Surface Albedo, and Cloud feedbacks [8], all of which are inherently tied to the presence and behavior of water in its various phases. Therefore, these feedbacks are natural responses to temperature changes, regardless of the original cause of warming, be it GHGs, incoming solar variability, or internal effects. They are not additive components to natural climate sensitivity, as treated by the IPCC, but rather integral parts of it [4].

This analysis reinforces a fundamental point: climate feedbacks are not external modifiers of climate sensitivity; rather, they are inherent to the system. Their combined effect is already embedded in the climate response function. The IPCC’s treatment of feedbacks as additive components used to “explain” high sensitivities in GCMs is conceptually flawed. Physically, Earth’s climate is governed by the mass balance of water in all its phases: ice, snow, liquid, vapor, and clouds. The dynamics between these phases are temperature-sensitive, and they constitute the feedback processes. Feedbacks aren’t just add-ons to the climate system, they are our climate.

Ocean Heat Content increase

In the introduction, the “heat in the pipeline” concept: the idea that heat stored in the deep, cold ocean layers could later resurface to significantly influence surface temperatures, was challenged. Without a substantial decrease in surface temperatures to reverse ocean stratification, this seems highly unlikely. Large and rapid temperature fluctuations during the pre-industrial era with rates up to plus, but also minus 0.05 K/year over several decennia as recorded in the Central England Temperature (CET) series [27], more than three times the rate observed today, further undermine the notion of a slow-release heat mechanism dominating surface temperature trends.

Ocean Heat Content must be related to solar energy. It is the prime source of energy heating the Earth thermal system. Almost 1 W/m2 of that 240 W/m2 solar flux that is in average entering the system, is presently remaining in the oceans. This is an order of magnitude larger than the estimated 0.1 W/m2 of geothermal heat upwelling from the Earth inner core [11]. Extra greenhouse gasses don’t add energy to the system, but just obstruct cooling. As shown in Section 5.3, this accounts for a radiation imbalance offset τ dFGHG/dt, or equivalent to a contribution to dOHC/dt of only about 0.08 W/m2.
.
As redistribution of “heat in the pipeline” will not change the total OHC, roughly 3/4 of the observed positive trend in OHC must at least be attributed to rising solar input. The oceans act in this way as our climate system’s thermal buffer. It will mitigate warming during periods of increased solar input and dampen cooling when solar input declines, underscoring its critical role in Earth’s climate stability.

The strong downwards slope in the OHC before 1970 confirms the observation in Section 5.4 and expressed by (12) that around the turning point t = ζ, the forcing trend in the SW-channel had to be negative. Moreover, the rather slowly increasing 700-2000m OHC data in Fig.7 indicate that most of the fluctuations have occurred relatively close to the surface. Heat from e.g. seafloor volcanism as “warming from below”, is expected to show up more pronounced in this 700-2000m OHC-profile. Although we cannot rule out geothermal influences [29], this observation makes them less likely.

ERBE measurements of radiative imbalance.

As the OHC seems to be primarily coupled to SWIN, the most plausible cause would involve rapid changes in SW-forcing. A sudden drop in cloud-cover might explain such changes, but no convincing observations could be found for the 1960-1980 period. Alternatively, changes in the latitudinal distribution of cloud-cover as illustrated by Fig.6, can result in similar radiative impacts due to the stark contrast between a positive radiation imbalance in the Tropics and a very negative imbalance at the Poles. The ENSO-oscillations in the Pacific Ocean around the equator are a typical example for such influences, as also illustrated in Fig.3 [10]. Shifts in cloud distribution are linked to changes in wind patterns and/or ocean currents, reinforcing the idea as indicated in Section 1, that even minor disruptions in horizontal heat transport can trigger major shifts in our climate’s equilibrium [29, 30]. Sharp shifts in Earth’s radiation imbalance like the one around 1970 as inferred from Fig.7, may even represent one of those alleged tipping points. But in this case, certainly not one triggered by GHGs. Ironically, some climate scientists in the early 1970s predicted an impending (Little) Ice Age [31].

While additional data (e.g. radiation measurements) are needed to draw firm conclusions, the available evidence already challenges the prevailing GHG-centric narrative again. GHG emissions, with their near constant forcing rate, cannot account for the timing nor the magnitude of historical OHC trends, as NOAA explicitly suggests [32]. Similarly, claims by KNMI that “accelerations” in radiation imbalance trends are GHG-driven [1], are not supported by data. And finally, the alarms around “heat in the pipeline” must be exaggerated if not totally misplaced. Given the similarities in radiation imbalance and GHG forcing rates around 1970 with today’s situation, we must conclude that this assumed heat manifested itself at that time apparently as “cooling in the pipeline”.

However, warnings for continued warming even if we immediately stop now with emitting GHGs are nevertheless, absolutely justified. Only, it isn’t warming then from that heat in the pipeline due to historical emissions that will boost our temperatures. Warming will continue to go on as long as natural forcings will be acting. These are already today’s dominant drivers behind global temperature trends. And unfortunately, they will not be affected by the illusion of stopping global warming as created by implementing Net-Zero policies.

Summary and conclusions

This analysis demonstrates that a global warming scenario driven solely by greenhouse gases (GHGs) is inconsistent with more than 20 years of observations from space and of Ocean Heat Content. The standard anthropogenic global warming (AGW) hypothesis, which attributes all observed warming to rising GHG concentrations, particularly CO2, cannot explain the observed trends. Instead, natural factors, especially long-term increase in incoming solar radiation, appear to play a significant and likely dominant role in global warming since the mid-1970s.

The observed increase in incoming solar radiation cannot be accounted for by the possible anthropogenic side effects of Albedo- and Cloud-feedback. All evidence points to the conclusion that this “natural” forcing with a trend of about 0.035 W/m2/year is equal to, or even exceeds the greenhouse gas related forcing of about 0.019 W/m2/year. Based on these values, only 1/3rd of the observed temperature trend can be of anthropogenic origin. The remaining 2/3rd must stem from natural changes in our climate system, or more broadly, in our entire Earth’ thermal system.

Moreover, the observed increase in Earth’s radiation imbalance appears to be largely unrelated to GHGs. Instead, it correlates strongly with natural processes driving increased incoming solar radiation. Claims of “acceleration” in the radiation imbalance due to GHG emissions are not supported by the trend in accurately measured GHG concentrations. If any acceleration in global warming is occurring, it is almost certainly driven by the increasing flux of solar energy—an inherently natural phenomenon not induced by greenhouse gases.

In summary, this analysis challenges the notion that GHGs are the primary drivers of recent climate change. It underscores the importance of accounting for natural variability, especially in solar input, when interpreting warming trends and evaluating climate models.

Note: Dr. Ad Huijser, physicist and former CTO of Philips and director of the Philips Laboratories, describes himself as “amateur climatologist”. However his approach to climate physics is quite professional, I think.

See Also:

Our Atmospheric Heat Engine

September 2025 Ocean SST Cooling

Posted on October 22 by Ron Clutz

The best context for understanding decadal temperature changes comes from the world’s sea surface temperatures (SST), for several reasons:

The ocean covers 71% of the globe and drives average temperatures;
SSTs have a constant water content, (unlike air temperatures), so give a better reading of heat content variations;
A major El Nino was the dominant climate feature in recent years.

So this September report is based again on HadSST 4, but with a twist. The data is slightly different in the new version, 4.2.0.0 replacing 4.1.1.0. Product page is here.

The Current Context

The chart below shows SST monthly anomalies as reported in HadSST 4.2 starting in 2015 through September 2025. A global cooling pattern is seen clearly in the Tropics since its peak in 2016, joined by NH and SH cycling downward since 2016, followed by rising temperatures in 2023 and 2024 and cooling in 2025.

Then in 2023-24 came an event resembling 2015-16 with a Tropical spike and two NH spikes alongside, all higher than 2015-16. There was also a coinciding rise in SH, and the Global anomaly was pulled up to 1.1°C in 2023, ~0.3° higher than the 2015 peak. Then NH started down autumn 2023, followed by Tropics and SH descending 2024 to the present. During 2 years of cooling in SH and the Tropics, the Global anomaly came back down, led by Tropics cooling from its 1.3°C peak 2024/01, down to 0.6C in September this year. Note the smaller peak in NH in July 2025 now declining along with SH and the Global anomaly cooler as well. Presently the Global anomaly is only slightly above the mean for this period

Comment:

A longer view of SSTs

To enlarge, open image in new tab.

Then in 2023 the Tropics flipped from below to well above average, while NH produced a summer peak extending into September higher than any previous year. Despite El Nino driving the Tropics January 2024 anomaly higher than 1998 and 2016 peaks, following months cooled in all regions, and the Tropics continued cooling in April, May and June along with SH dropping. After July and August NH warming again pulled the global anomaly higher, September through January 2025 resumed cooling in all regions, continuing February through April 2025, with little change in May,June and July despite upward bumps in NH. Now temps in all regions are cooling August and September 2025.

Contemporary AMO Observations

The pattern suggests the ocean may be demonstrating a stairstep pattern like that we have also seen in HadCRUT4.

The rose line is the average anomaly 1982-1996 inclusive, value 0.18. The orange line the average 1982-2025, value 0.41 also for the period 1997-2012. The red line is 2015-2025, value 0.69. As noted above, these rising stages are driven by the combined warming in the Tropics and NH, including both Pacific and Atlantic basins.

Curiosity: Solar Coincidence?

Summary

uss-pearl-harbor-deploys-global-drifter-buoys-in-pacific-ocean

USS Pearl Harbor deploys Global Drifter Buoys in Pacific Ocean

About Sea Surface Temperatures

Posted on October 12 by Ron Clutz

Background from NOAA Climate.gov

Q: What’s the temperature of water at the ocean’s surface?
A: Colors on the map show the temperature of water right at the ocean’s surface. The darkest blue shows the coldest water: floating sea ice is usually present in these areas. Lighter shades of blue show temperatures of up to 80°F. White and orange areas show where surface temperatures are higher than 80°F, warm enough to fuel tropical cyclones or hurricanes.

Q: Where do these measurements come from?
A: Satellite instruments measure sea surface temperature—often abbreviated as SST—by checking how much energy comes off the ocean at different wavelengths. Computer programs merge sea surface temperatures from ships and buoys with the satellite data, and incorporate information from maps of sea ice. To produce the daily maps, programs invoke mathematical filters to combine and smooth data from all three sources.

Q: Why do these data matter?
A: While heat energy is stored and mixed throughout the depth of the ocean, the temperature of water right at the sea’s surface—where the ocean is in direct contact with the atmosphere—plays a significant role in weather and short-term climate. Where sea surface temperatures are high, relatively large amounts of heat energy and moisture enter the atmosphere, sometimes producing powerful, drenching storms downwind. Conversely, lower sea surface temperatures mean less evaporation. Global patterns of sea surface temperatures are an important factor for weather forecasts and climate outlooks.

Q: How did you produce these snapshots?
A: Data Snapshots are derivatives of existing data products: to meet the needs of a broad audience, we present the source data in a simplified visual style. NOAA’s Climate Data Records Program produces the Opitimum Interpolated Sea Surface Temperature files. To produce our images, we run a set of scripts that access the source files, re-project them into desired projections at various sizes, and output them with a custom color bar.

With the federal government shutdown, dataset updates are uncertain, but OISST is current and shows how presently the ocean is cooling down from it’s 2024 high temperatures.

Note: Daily SST Ocean Temperature Graphic, 1982-2025

Use the options below to generate graphics of daily sea surface temperatures since 1982 using data from NOAA’s Optimum Interpolation Sea Surface Temperature (OISST) v2.1 dataset. [The chart above defines Global as 60°N to 60°S.] These graphics will update daily, or as data becomes available on the Climate Reanalyzer website. Note the most recent two weeks of data are considered preliminary. Specific information about the data can be found here.

My Comment:

The chart shows how 2025 is tracking ~half a degree F cooler than 2024. That may not seem significant, except that the ocean covers 71% of the Earth’s surface, and any SST warming is reported in numbers of zettajoules. This is explained at the EPA website Climate Change Indicators: Ocean Heat:

The top 700 meters of the ocean contain 63% of the ocean’s heat content. The data shows that ocean layer has warmed about a zettajoule (1×10^22 joules) yearly since 1990.

For reference, an increase of 1 unit on this graph (1 × 10^22 joules) is equal to approximately 17 times the total amount of energy used by all the people on Earth in a year (based on a total global energy supply of 606 exajoules in the year 2019, which equates to 6.06 × 10^20 joules).

It appears that presently we may be about to lose that amount of energy through oceanic cooling. And the sun could be to blame:

Scare du jour Marine Heat Waves

Posted on October 8 by Ron Clutz

If you watch legacy media, you must also be wondering after seeing all the current headlines about Marine Heat Waves raising the ocean to its boiling point.

Ocean heatwaves are breaking Earth’s hidden climate engine, Science Daily

The Pacific Ocean is overheated, making fall feel like summer, CBC

The ‘blob’ is back — except this time it stretches across the entire north Pacific, CNN

Record marine heatwaves may signal a permanent shift in the oceans, New Scientist

Global warming drives a threefold increase in persistence and 1 °C rise in intensity of marine heatwaves, PNAS

Etc., etc. etc.

The last one is the paper driving this recent clamor over Ocean SSTs Marcos et al. 2025 From the abstract:

We determine that global warming is responsible for nearly half of these extreme events and that, on a global average, it has led to a three-fold increase in the number of days per year that the oceans experience extreme surface heat conditions. We also show that global warming is responsible for an increase of 1 °C in the maximum intensity of the events. Our findings highlight the detrimental role that human-induced global warming plays on marine heatwaves. This study supports the need for mitigation and adaptation strategies to address these threats to marine ecosystems.

The coordinated media reports are exposed by all of them containing virtually the same claim:

As climate change causes our planet to warm, marine heatwaves are
becoming more frequent, more intense, and longer lasting.

Animation shows locations of moderate to severe MHWs mid-month 2025 January to October. A marine heatwave is defined as one where the measured temperature is within 10% of the maximum values observed (i.e., above the Threshold (90th quantile) , for at least 5 consecutive days. For this, the intensity is compared to the difference between the climatological mean and the 90th percentile value (threshold). A marine heatwave intensity between 1 and 2 times this difference corresponds to a heatwave of moderate category; between 2 and 3 times, to a strong category; between 3 and 4 times, to a severe category; and a difference greater than 4 times corresponds to an extreme category.

First some background context on the phenomena (in italics with my bolds).

Background from perplexity.ai How Do Warm and Cool Ocean Blobs Circulate?

Warm and cool ocean blobs circulate through distinct oceanic and atmospheric processes, often linked to major currents and atmospheric patterns.

Warm ocean blobs, such as the “warm blob” in the northeast Pacific, form due to atmospheric circulation changes triggered by factors like Arctic warming. This leads to a high-pressure system over the region, weakening westerly winds and reducing ocean heat loss, causing surface waters to warm and creating persistent warm anomalies. The formation of these warm blobs involves a feedback loop between weakened winds, reduced ocean-atmosphere heat exchange, and ocean circulation, which retains heat in the mixed layer of the ocean.

Cool ocean blobs, like the North Atlantic “cold blob,” are influenced by weakening of the Atlantic Meridional Overturning Circulation (AMOC). This circulation moves warm, salty water northward, which cools, sinks, and then the cooler deep water travels southward in a conveyor-belt style flow. The cold blob forms when excess freshwater from ice melt dilutes the salty water, reducing its density and sinking ability, weakening this circulation and causing cooler surface water to persist. This cooling also affects the atmosphere by reducing water vapor, which decreases greenhouse effect locally and amplifies the cold anomaly, creating a coupled ocean-atmosphere feedback loop.

In summary, warm and cool ocean blobs circulate through a combination of ocean current dynamics and atmospheric interactions. Warm blobs form where atmospheric changes reduce ocean heat loss and circulation shifts retain heat, while cool blobs occur where circulation weakens, allowing cooler, less dense waters to persist and affect atmospheric conditions as well.

Then a summary of the issues undermining the alarmists’ claim.

From perplexity.ai What are reasons to doubt climate change is increasing marine heatwaves?

There are several reasons to doubt that climate change is definitively increasing the frequency, intensity, duration, and spatial extent of marine heatwaves, based on some ongoing scientific debates and uncertainties.

Natural Variability and Other Factors

♦ Marine heatwaves are influenced by natural climate variability, such as El Niño, Pacific Decadal Oscillation (PDO), and other oceanic and atmospheric processes. These phenomena can cause fluctuations in sea surface temperatures independent of long-term climate change, leading to periods of warmer ocean conditions that may be mistaken for climate-driven trends.

♦ Some studies emphasize the role of internal ocean variability, which can cause significant short-term temperature anomalies without requiring a direct link to anthropogenic climate change.

Complexity of Attribution

♦ The attribution of marine heatwave trends specifically to climate change involves complex modeling and statistical analysis, which can have uncertainties. Certain models suggest that long-term temperature increases are the primary driver, but the contribution of natural variability remains significant and sometimes difficult to separate clearly from climate signals.

♦ Regional differences and localized oceanic processes can obscure the global patterns, leading some scientists to argue that not all observed phenomena are directly attributable to climate change, particularly in areas with strong natural variability.

Limitations of Climate Models

♦ Climate models predicting future marine heatwave conditions depend heavily on assumptions about greenhouse gas emissions and other factors. These models often have limitations in resolution and in capturing small-scale processes, which could lead to overestimations or underestimations of climate change impacts.

Data Gaps and Uncertainties

♦ Although current observations show increasing trends in marine heatwaves, data gaps exist, especially in remote or deep-sea regions, making comprehensive global assessments challenging. These gaps contribute to uncertainty regarding the full extent and causality of observed changes.

♦ The precise long-term ecological impacts and possible adaptation or resilience mechanisms of marine ecosystems also remain uncertain, complicating the understanding of climate change’s role versus natural variability.

Summary

While a considerable body of evidence supports the role of climate change in increasing marine heatwaves, skepticism persists due to the influence of natural variability, model limitations, regional differences, and data gaps. These factors suggest that attribution is complex, and ongoing research continues to refine our understanding of the relative contributions of human influences and natural climate fluctuations.

Finally, a discussion of a specific example revealing flawed methods supposedly connecting CO2 emissions to marine heatwaves.

Much Ado About Marine Heat Waves

The promotion of this scare was published in 2022 at Nature by Barkhordarian et al. Recent marine heatwaves in the North Pacific warming pool can be attributed to rising atmospheric levels of greenhouse gases. This post will unpack the reasons to distrust this paper and its claims. First the Abstract of the subject and their declared findings in italics with my bolds.

Abstract

Over the last decade, the northeast Pacific experienced marine heatwaves that caused devastating marine ecological impacts with socioeconomic implications. Here we use two different attribution methods and show that forcing by elevated greenhouse gases levels has virtually certainly caused the multi-year persistent 2019–2021 marine heatwave. There is less than 1% chance that the 2019–2021 event with ~3 years duration and 1.6 ∘C intensity could have happened in the absence of greenhouse gases forcing. We further discover that the recent marine heatwaves are co-located with a systematically-forced outstanding warming pool, which we attribute to forcing by elevated greenhouse gases levels and the recent industrial aerosol-load decrease. The here-detected Pacific long-term warming pool is associated with a strengthening ridge of high-pressure system, which has recently emerged from the natural variability of climate system, indicating that they will provide favorable conditions over the northeast Pacific for even more severe marine heatwave events in the future.

Background on Ocean Warm Pools

Wang and Enfield study is The Tropical Western Hemisphere Warm Pool Abstract in italics with my bolds.

Abstract

The Western Hemisphere warm pool (WHWP) of water warmer than 28.5°C extends from the eastern North Pacific to the Gulf of Mexico and the Caribbean, and at its peak, overlaps with the tropical North Atlantic. It has a large seasonal cycle and its interannual fluctuations of area and intensity are significant. Surface heat fluxes warm the WHWP through the boreal spring to an annual maximum of SST and areal extent in the late summer/early fall, associated with eastern North Pacific and Atlantic hurricane activities and rainfall from northern South America to the southern tier of the United States. SST and area anomalies occur at high temperatures where small changes can have a large impact on tropical convection. Observations suggest that a positive ocean-atmosphere feedback operating through longwave radiation and associated cloudiness is responsible for the WHWP SST anomalies. Associated with an increase in SST anomalies is a decrease in atmospheric sea level pressure.

Chou and Chou published On the Regulation of the Pacific Warm Pool Temperature:

Abstract

Analyses of data on clouds, winds, and surface heat fluxes show that the transient behavior of basin-wide large-scale circulation has a significant influence on the warm pool sea surface temperature (SST). Trade winds converge to regions of the highest SST in the equatorial western Pacific. The reduced evaporative cooling due to weakened winds exceeds the reduced solar heating due to enhanced cloudiness. The result is a maximum surface heating in the strong convective and high SST regions. The maximum surface heating in strong convective regions is interrupted by transient atmospheric and oceanic circulation. Regions of high SST and low-level convergence follow the Sun. As the Sun moves away from a convective region, the strong trade winds set in, and the evaporative cooling enhances, resulting in a net cooling of the surface. We conclude that the evaporative cooling associated with the seasonal and interannual variations of trade winds is one of the major factors that modulate the SST distribution of the Pacific warm pool.

Comment:

So these are but two examples of oceanographic studies describing natural factors driving the rise and fall of Pacific warm pools. Yet the Nature paper claims rising CO2 from fossil fuels is the causal factor, waving away natural processes. Skeptical responses were already lodged upon the first incidence of the North Pacific marine heat wave, the “Blob” much discussed by west coast US meteorologists. One of the most outspoken against the global warming attributionists has been Cliff Mass of Seattle and University of Washington. Writing in 2014 and 2015, he observed the rise and fall of the warming blob and then posted a critique of attribution attempts at his blog. For example, Media Miscommunication about the Blob. Excerpts in italics with my bolds.

Blob Media Misinformation

One of the most depressing things for scientists is to see the media misinform the public about an important issue.

During the past few days, an unfortunate example occurred regarding the warm water pool that formed over a year ago in the middle of the north Pacific, a.k.a., the blob. Let me show how this communication failure occurred, with various media outlets messed things up in various ways.

The stimulant for the nationwide coverage of the Blob was a very nice paper published by Nick Bond (UW scientist and State Climatologist), Meghan Cronin, Howard Freeland, and Nathan Mantua in Geophysical Research Letters.

This publication described the origin of the Blob, showing that it was the result of persistent ridging (high pressure) over the Pacific. The high pressure, and associated light winds, resulted in less vertical mixing of the upper layer of the ocean; with less mixing of subsurface cold water to the surface. Furthermore, the high pressure reduced horizontal movement of colder water from the north. Straightforward and convincing work.

The inaccurate press release then led to a media frenzy, with the story going viral. And unfortunately, many of the media got it wrong.

There were two failure modes. In one, the headline was wrong, but the internal story was correct. . . In the second failure mode, the story itself was essentially flawed, with most claiming that the Blob off of western North America was the cause of the anomalous circulation (big ridge over West Coast, trough over the eastern U.S.). (The truth: the Blob was the RESULT of the anomalous circulations.) That the Blob CAUSED the California drought or the cold wave in the eastern U.S. These deceptive stories were found in major outlets around the country, including the Washington Post, NBC News, and others.

Blob Returns, Attribution Misinformation

When the Blob returned 2020-2021, Cliff Mass had cause to again lament how the public is misled. This time misdirection instigated by activist scientists using flawed methods. His post Miscommunication in Recent Climate Attribution Studies. Excerpts in italics with my bolds.

This attribution report, and most media stories that covered it, suggested a central role for global warming for the heatwave. As demonstrated in my previous blog, their narrative simply does not hold up to careful examination.

This blog will explain why their basic framing and approach is problematic, leading readers (and most of the media) to incorrect conclusions.

For the heatwave, the attribution folks only examine the statistics of temperatures hitting the record highs (108F in Seattle), but avoid looking at the statistics of temperature exceeding 100F, or even the record highs (like 103F in Seattle). There is a reason they don’t do that. It would tell a dramatically different (and less persuasive) story.

In the attribution studies, the main technology for determining changed odds of extreme weather is to use global climate models. First, they run the models with greenhouse gas forcing (which produces more extreme precipitation and temperature), and then they run the models again without increased greenhouse gases concentrations. By comparing the statistics of the two sets of simulations, they attempt to determine how the odds of extreme precipitation or temperature change.

Unfortunately, there are serious flaws in their approach: climate models fail to produce sufficient natural variability (they underplay the black swans) and their global climate models don’t have enough resolution to correctly simulate critical intense, local precipitation features (from mountain enhancement to thunderstorms). On top of that, they generally use unrealistic greenhouse gas emissions in their models (too much, often using the RCP8.5 extreme emissions scenario) And there is more, but you get the message. ( I am weather/climate modeler, by the way, and know the model deficiencies intimately.)

Vaunted Fingerprinting Attribution Is Statistically Unsound

From Barkhordarian et al.

Unlike previous studies which have focused on linking the SST patterns in the North Pacific to changes in the oceanic circulation and the extratropical/tropical teleconnections2,12,17,18,20,24,26, we here perform two different statistical attribution methodologies in order to identify the human fingerprint in Northeast Pacific SST changes both on multidecadal timescale (changes of mean SST) and on extreme SST events on daily timescale (Marine Heatwaves). Evidence that anthropogenic forcing has altered the base state (long-term changes of mean SST) over the northeast Pacific, which is characterized by strong low-frequency SST fluctuations, would increase confidence in the attribution of MHWs27, since rising mean SST is the dominant driver of increasing MHW frequency and intensity, outweighing changes due to temperature variability1,2.

In this study, we provide a quantitative assessment of whether GHG forcing, the main component of anthropogenic forcings, was necessary for the North Pacific high-impact MHWs (the Blob-like SST anomalies) to occur, and whether it is a sufficient cause for such events to continue to repeatedly occur in the future. With these purposes, we use two high-resolution observed SST datasets, along with harnessing two initial-condition large ensembles of coupled general circulation models (CESM1-LE28,29 with 35 members, and MPI-GE30 with 100 members). These large ensembles can provide better estimates of an individual model’s internal variability and response to external forcing31,32, and facilitate the explicit consideration of stochastic uncertainty in attribution results33. We also use multiple single-forcing experiments from the Detection and Attribution Model Intercomparision Project (DAMIP34) component of Coupled Model Intercomparison Project phase 6 (CMIP635).

From Barkhordarian et al. References

The IPCC’s attribution methodology is fundamentally flawed

The central paper underpinning the attribution analysis was assessed and found unreliable by statistician Ross McKitrick’s published evaluation. Excerpts in italics with my bolds.

One day after the IPCC released the AR6 I published a paper in Climate Dynamics showing that their “Optimal Fingerprinting” methodology on which they have long relied for attributing climate change to greenhouse gases is seriously flawed and its results are unreliable and largely meaningless. Some of the errors would be obvious to anyone trained in regression analysis, and the fact that they went unnoticed for 20 years despite the method being so heavily used does not reflect well on climatology as an empirical discipline.

My paper is a critique of “Checking for model consistency in optimal fingerprinting” by Myles Allen and Simon Tett, which was published in Climate Dynamics in 1999 and to which I refer as AT99. Their attribution methodology was instantly embraced and promoted by the IPCC in the 2001 Third Assessment Report (coincident with their embrace and promotion of the Mann hockey stick). The IPCC promotion continues today: see AR6 Section 3.2.1. It has been used in dozens and possibly hundreds of studies over the years. Wherever you begin in the Optimal Fingerprinting literature (example), all paths lead back to AT99, often via Allen and Stott (2003). So its errors and deficiencies matter acutely.

Abstract

Allen and Tett (1999, herein AT99) introduced a Generalized Least Squares (GLS) regression methodology for decomposing patterns of climate change for attribution purposes and proposed the “Residual Consistency Test” (RCT) to check the GLS specification. Their methodology has been widely used and highly influential ever since, in part because subsequent authors have relied upon their claim that their GLS model satisfies the conditions of the Gauss-Markov (GM) Theorem, thereby yielding unbiased and efficient estimators.

But AT99:

stated the GM Theorem incorrectly, omitting a critical condition altogether,
their GLS method cannot satisfy the GM conditions, and
their variance estimator is inconsistent by construction.
Additionally, they did not formally state the null hypothesis of the RCT nor
identify which of the GM conditions it tests, nor
did they prove its distribution and critical values, rendering it uninformative as a specification test.

The continuing influence of AT99 two decades later means these issues should be corrected. I identify 6 conditions needing to be shown for the AT99 method to be valid.”

In Conclusion, McKitrick:

One point I make is that the assumption that an estimator of C provides a valid estimate of the error covariances means the AT99 method cannot be used to test a null hypothesis that greenhouse gases have no effect on the climate. Why not? Because an elementary principle of hypothesis testing is that the distribution of a test statistic under the assumption that the null hypothesis is true cannot be conditional on the null hypothesis being false. The use of a climate model to generate the homoscedasticity weights requires the researcher to assume the weights are a true representation of climate processes and dynamics.

The climate model embeds the assumption that
greenhouse gases have a significant climate impact.

Or, equivalently, that natural processes alone cannot generate a large class of observed events in the climate, whereas greenhouse gases can. It is therefore not possible to use the climate model-generated weights to construct a test of the assumption that natural processes alone could generate the class of observed events in the climate.

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