Climate Science

The Hottest Year Shell Game

When it comes to climate science, always keep eyes on the prize.

The Distorted Reporting of Global Average Temperature 2025 and its relevance to the Paris Agreement

The video by Philosophical Investigations uncovers some misleading claims by people who should know better. For those who prefer reading, below is a transcript with my bolds and added images.

With the end of year 2025, the crucial questions to be answered by climate scientists were:

♦ how much has global average temperature increased since the pre-industrial period 1850 to 1900, and
♦ how does this increase compare to the Paris Agreement overarching goals?

These goals being to hold the increase in the global average temperature less than 2 degrees Celsius above pre-industrial levels and pursue efforts to limit the temperature increase to 1.5 degrees Celsius above pre-industrial levels. Note the relevance of the term pre-industrial.

The IPCC uses the reference period 1850 to 1900 to represent pre-industrial temperature. The period 1850 to 1900 and the term pre-industrial are to a large extent interchangeable in the discussion that follows. We can now provide examples of how the global average temperature at year end 2025 was reported.

Berkeley Earth reported that in 2025 the global annual average temperature was estimated at 1.44 degrees Celsius above pre-industrial levels. The WMO reported that the global average surface temperature was 1.44 degrees Celsius above the 1850 to 1900 average. The UK Met Office reported that 2025 was 1.41 degrees Celsius above the 1850 to 1900 global average.

NOAA reported that 2025 exceeded the pre-industrial 1850 to 1900 average by 1.34 degrees Celsius. All these figures appear to measure the amount of global warming as being very close to the Paris Agreement lower limit of 1.5 degrees Celsius above pre-industrial levels. Just to double check this channel calculated global warming using the standard IPCC methodology and the official published NOAA data, the global average temperature anomaly 1850 to 1900 equals minus 0.165 degrees Celsius.

The global average temperature anomaly for the 30 year period 1996 to 2025 equals plus 0.751 degrees Celsius. Therefore, the global average temperature has warmed by 0.916 degrees Celsius since 1850 to 1900. This is a large discrepancy from the NOAA 2025 report of 1.34 degrees Celsius.

To be specific, it is a discrepancy of 46.28%. So, how did such a large discrepancy come about?

A brief background and analysis will reveal a somewhat disturbing answer. The 2016 Paris Agreement did not specify how to measure any increase in global average temperature, nor did it specify what precisely was meant by pre-industrial levels. To correct this lack of scientific clarity in the Paris Agreement, the IPCC walked its readers through the process of defining global warming.

First, it specified that the reference period 1850 to 1900 is to be used to represent pre-industrial temperature. Once scientists had defined pre-industrial, the next step is to calculate the amount of warming at any given time relative to that reference period. Warming is defined as the increase in the 30-year global average of combined air temperature over land and water temperature at the ocean surface relative to the 1850 to 1900 pre-industrial period.

[Note: One important reason that the period 1850-1900 serves as a useful baseline of climate utopia is that almost no one has any idea what the climate looked like back then, much less the climate impacts experienced. Most modern climate records start in the 20th century, and to the extent that the IPCC considers pre-20th climate it is in terms of physical quantities and not impacts or risks.

Estimated decadal deaths related to weather and climate for four decades: 1870s, 1920s, 1970s, and 2020s (estimated based on deaths over the past decade). These estimates are highly uncertain and 1870s and 1920s numbers are certainly underestimates. They should be interpreted as orders of magnitude and not as precise figures. Sources: Davis 2017, Our World in Data

The figure above shows estimated decadal deaths related to weather and climate extremes for four decades, each separated by a half-century, starting with the 1870s.]

Why 30 years? The 30-year time span accounts for the effect of natural variability, which can cause global temperatures to fluctuate from one year to the next. An earlier report had also emphasised that due to natural variability, trends based on short records that are very sensitive to the beginning and end dates, do not in general reflect long-term climate trends. That covers the necessary background.

Now, the analysis of the critical question. Why does the IPCC methodology give a calculation of 0.916°C but NOAA reports 1.34°, WMO reports 1.44°C, UK Met Office reports 1.41°C, Berkeley Earth reports 1.44°C? It is disturbing to highlight that the reason for the discrepancies involves a certain amount of guile leading to misinformation. On the one hand, it seems as if we are being informed of the increase in global average temperature since 1850-1900 as related to the Paris Agreement goals.

But in fact, we are merely being informed of a comparison of the global average temperature of the single year 2025 with the global average temperature of the 51-year period 1850-1900. A comparison which is absolutely irrelevant with respect to the Paris Agreement goals. And quite emphatically, does nothing to answer the questions how much has global average temperature increased since the pre-industrial period 1850-1900 and how does this increase compare to the Paris Agreement overarching goals?

This is because, instead of comparing a 30-year global average temperature
with the 51-year period 1850-1900, these organisations have
compared a single year 2025 with 1850-1900.

This is an invalid methodology that produces the exact results these organisations have duly reported. This can be demonstrated quite easily by again using NOAA data but substituting the 30-year period 1996-2025 with the 1-year period 2025-2025. The global average temperature anomaly 1850-1900 remains the same at minus 0.165 degrees celsius.

The global average temperature anomaly for this single year 2025 equals plus 1.17 degrees celsius. The global average temperature was therefore claimed to have warmed by 1.335 degrees celsius, which rounds up to 1.34 degrees celsius, exactly as reported by NOAA. All these organisations underlined and previously quoted are guilty of using this invalid methodology.

Why would these seemingly august and respected organisations do this when they knew, as stated by the UK Met Office, that a 30-year period is more relevant than the average for a single or small number of years when considering the agreement on climate change? Could it possibly be that the figure of 1.34 sounds more alarming and much closer to the Paris Agreement of 1.5 than does the valid figure of 0.916? And that is why these organisations have deviated from the standard methodology. It is difficult to believe but it is a possibility. Whatever the answer to this elusive question may be, we now provide definitive answers to the crucial questions that were to be answered by climate scientists at end of year 2025.

How much has global average temperature increased since the pre-industrial period 1850-1900? 0.916 degrees celsius. How does this increase compare to the Paris Agreement overarching goals? It is 0.584 degrees celsius below the lower limit of 1.5 degrees celsius. That concludes the main points of this video but we could not resist a two-minute post-script.

It may be argued that the statement 2025 exceeded the pre-industrial 1850-1900 average by 1.34 degrees celsius was merely intended to give the reader a feel for how much warmer it is now compared to the 1850-1900 period. There are two points to make in such a case. The first point is that 1850-1900 was an unusually cold period. It was in fact part of the Little Ice Age. The IPCC states that the Little Ice Age was characterised by multiple expansions of mountain glaciers worldwide. It was a roughly defined period but generally occurred between 1400 and 1900.

The second point is that it seems silly to compare the warm year 2025 to a cold average of 51 years.

Why not compare 2025 to some of the warmer years that took place during 1850-1900? For example 1878. In this case 2025 was 1.04 degrees celsius warmer than 1878. This difference is not close to the Paris Agreement 1.5 degrees celsius. Or take 1877. In this case 2025 was 1.05 degrees celsius warmer than 1877. Again not close to the Paris Agreement 1.5 degrees celsius.

It could be surmised that perhaps this is why the single year 2025 was instead compared to the 51-year average of an unusually cold period. It may be very difficult to believe but it is a possibility that was the reason. Whatever the reason, there is no doubt that all the organisations underlined and quoted have ignored the scientific methodology and advice of the IPCC that short records are very sensitive to the beginning and end dates and do not, in general, reflect long-term climate trends.

Shortage of Climate Comedians

Posted on January 28 by Ron Clutz

Chris Morrison provides examples of malarky from alarmist Jim Dale in his Daily Sceptic article Treasure Climate Comedian Jim Dale While You Can: We May Never See His Like Again. Exerpts in italics with my bolds. H/T Climate-science.press.

Climate comedy turn Jim Dale continues to tour the Gaiety Halls of broadcast media, delighting audiences with his own word-salad English and his knack for getting most facts wrong. Fans were not disappointed by an extended performance, here, start around 2hr 38 mins, last week on Mark Dolan’s TalkTV show when he falsely claimed Costa Rica had reached Net Zero and the polar ozone hole had closed. Readers might be advised not to organise drinking parties around Jim’s much-cherished appearances. If a shot is taken every time the great entertainer gets a climate or Net Zero fact wrong, you’d be Brahms and Liszt quicker than you could say Julia Hartley-Brewer.

A number of countries are already at Net Zero carbon emissions, claimed Dale, and he gave Costa Rica as an example. Sorry Jim, treble Guaro Sours all round: Costa Rica is nowhere near Net Zero. In fact, the Carbon Action Tracker notes that the current government is sending “worrying signals that the full implementation of the climate policies and measures necessary to meet Costa Rica’s own targets could be deferred”. Key electric public transport projects have been paused or downscaled, while the current President has announced his opposition to an oil moratorium, along with an intention to explore Costa Rica’s hydrocarbon reserves. For some time, Costa Rica has presented itself as a poster country for eco-tourism and sustainability, but it was never near Net Zero. There comes a time when all the virtue signalling has to stop.

Hard reality seems to have bitten the territory, as it has every other country
taking a serious look at the stupidity of the Net Zero fantasy.

Put down the liquor bottle (just for a very short while): our climate clot got it partly right when he said two or three countries had hit Net Zero. One country often mentioned is Bhutan, a landlocked territory the size of Belgium in the eastern Himalayas. Mountains give Bhutan huge hydroelectric power, while 93% of the land is covered in carbon-dioxide-absorbing forest. Meanwhile, about half the population of 800,000 is involved in subsistence farming. As a future model for Net Zero, it leaves a lot to be desired.

Perhaps Jim could explain on his next much-awaited guest slot why Bhutan, a Net Zero country seemingly perfect in every respect, requires foreign aid of $13.7 billion over the next decade for “mitigation” costs to keep it on the straight and narrow Net Zero path. Sustaining its contribution and ambitions are said in its third Nationally Determined Contribution report to the UN to require “continued and predictable” international financial support.

Of course it does. Not a bad little earner for a country with an annual GNP of just over $3 billion. The cynical might be forgiven for reading into its words a threat along the lines of: cough up or the trees get it.

Time to refresh our glasses again, as our comedic clown then told Mark Dolan that the South Pole ozone hole had closed or, to put it in Jim’s word-salad English: “The ozone layer was a perfectly tenable thing that occurred and the hole closed because we got out of aerosols that managed that actually.” Alas, the hole has not closed, despite a 35-year ban on aerosol-using chlorofluorocarbons (CFC) gases. The thinning, rather than a hole, appears to be a largely natural event that changes thickness on an annual, seasonal basis.

A recently published science paper by three New Zealand-based scientists noted that the three years 2020–2023 witnessed the re-emergence of large, long-lived holes over Antarctica. The scientists observed that in the eight years to 2022, five showed similarly large temporary holes occurring in the spring months. In 2023, the European Space Agency said the hole was one of the biggest ever recorded, measuring 26 million sq kms. Perish the thought that banning CFCs didn’t make much difference – surely all those Nobel science prizes were not handed out in vain for a totemic environmental scare that proved such an inspiration for all the subsequent attempts to induce mass climate panic? Except when Jim unwisely brings it up, you don’t hear much about the ozone hole these days, with activists quietly extending its supposed disappearance to around 2060.

The ozone over Antarctica is recovering. Here, the four globes show monthly-averaged total ozone over Antarctica in October. The graph shows each year’s October average minimum (white dots) over Antarctica. The red curve represents a smoothed version of the white dots. NASA qzonewatch

Your correspondent has a few tips to offer if readers ever need to handle Jim in a public debate. The first task is to stop him constantly interrupting and shouting over you. This is best done by first listening to what he has to say and, at the first sign of trouble, demanding the same courtesy be extended when it is your turn to speak. Last May, I found myself with him on TalkTV with the excellent ringmaster Ian Collins – here, the entertainment starts at around 35m 30s. It worked reasonably well, despite the overwhelming temptation at one point to burst out laughing when Jim claimed the source of his climate information was NASA, “who send people to the Moon and Mars”. Extra fun can be inserted into the proceedings by noting that Dale is on record as wanting to jail climate ‘deniers’. At my prompting, Ian Collins asked him if this was true and the ensuing word-salad explanation was a pure delight. Only Jim can explain in his special language that it is not quite like that, while at the same time suggesting that it is precisely like that.

The market for data-free climate scares is starting to dry up across mainstream media. Gone are the days when the BBC’s Esme Stallard could give us her “climate change could make beer taste worse”. No more shall we see Georgina Rannard make the obvious mistake of putting a date on impending doom as she did in 2023 with a ‘scientists say’ article warning that the Gulf Stream warm currents “could collapse as early as 2025”.

Perish the thought, but soon only Jim Dale might be left to keep the nation
amused with his carry on climate catastrophising routine.

Al Gore’s “Inconvenient Truth” Decrepit at Age 20

Posted on January 27 by Ron Clutz

Kevin Killough describes the decay of Gore’s signature movie in his Just the News article Al Gore’s ‘Inconvenient Truth’ turns 20, and critics say biggest disaster is its failed predictions. Excerpts in italics with my bolds and added images.

Twenty years ago “An Inconvenient Truth” received a standing ovation at the
Sundance Film Festival. Though it was full of predictions that never
came to pass, it was a key catalyst of the climate activist movement.

Twenty years ago Monday, former Vice-President Al Gore’s documentary on global warming, “An Inconvenient Truth,” premiered at the Sundance Film Festival and received a standing ovation. The 2006 documentary was released to theaters the following May and went on to gross over $25 million worldwide.

Gore’s film was a primary catalyst for the climate activist movement, and it generated a lot of concern about global warming following its release. The movie left audiences with the impression that the human race was hurtling toward a dystopian future on a planet baking in unbearable temperatures where extreme weather caused frequent disasters.

Almost 13 years to the day after its release, Rep. Alexandria Ocasio-Cortez, D-N.Y., was telling people the world would end in 12 years – presumably five years from now – because of the burning of fossil fuels.

Matt Wielicki, who writes about climate and energy on his “Irrational Fear” Substack, was once an assistant professor in the Department of Geological Sciences at the University of Alabama. In the early part of his academic career, he taught at a local college.

Al Gore with a version of the Hockey Stick graph in the 2006 movie An Inconvenient Truth

He told Just the News that he showed “An Inconvenient Truth” to his students. Over time, he began to question the “gloom and doom” narratives Gore presents in his film, he said.

“People took that as a starting point, and they just kept running further and further with it,” Wielicki said.

Gore’s film, however, was full of numerous predictions that turned out to be wrong, and it’s likely that the world will not end in 2031, as Ocasio-Cortez predicted.

Stubborn ice

Among the predictions Gore made in the documentary is that Africa’s Mt. Kilimanjaro would have no more snow on it by 2016. In 2020, The Times reported that the snow on the 19,000-foot mountain remained, despite Gore’s predictions. But the documentary had caused some to rush to climb the mountain before the snow disappeared. Instead, the tourists are surprised to find glaciers still clinging to it.

Gore also predicted that Glacier National Park would be “the park formerly known as Glacier” after all the ice melted away in the blazing hot temperatures that were to descend upon the human race. The claim made a big mark, and federal agencies began looking closely at glaciers.

The U.S. Geological Survey predicted all the glaciers in the park would be gone by 2020. Signs were placed throughout the park warning visitors of the impending end of glaciers, which never happened. Instead, CNN reported, the signs had to be removed in 2020 when it was clear the glaciers remained.

Gore also connected Hurricane Katrina to global warming – later renamed climate change – and he predicted that these storms would become more frequent. The reality of human contributions to hurricane activity is far more nuanced and uncertain than Gore discusses in the documentary.

Integrated Storm Activity Annually over the Continental U.S. (ISAAC). Value is the Accumulated Cyclone Energy from all storms over land.

The National Oceanic and Atmospheric Administration has a section on its website dedicated to the topic. The page reads.

“In summary, it is premature to conclude with high confidence that human-caused increases in greenhouse gases have caused a change in past Atlantic basin hurricane activity that is outside the range of natural variability, although greenhouse gases are strongly linked to global warming,”

Uncertainty and nuance

Meteorologist Chris Martz said that climate science is full of the kind of uncertainty and nuance you see on the NOAA website, which “An Inconvenient Truth” dismisses entirely.

Since Gore’s film was released – which was given a sequel in 2017 – Gore has continued to make false predictions, the meteorologist said. In 2009, Gore stated that the Arctic would be ice-free in summer within five to seven years. As of today, the Arctic still has ice in summer.

“We look at the Arctic ice now and yes, it’s declined since 1979 when satellite records began … But over the last 18 to 20 years, there’s really been no trend. And this caught scientists off guard. The models never predicted this,” Martz told Just the News.

He also said there’s been multiple studies on Arctic ice, and while some predicted an ice-free Arctic, others find the ice extent in the region recedes or grows as a result of natural variability.

Predictions of cataclysm stemming from climate change regularly get reported in the media, but there’s little reporting when the predictions fail. In 2022, NBC News was one of many outlets reporting that California and the American West were in the midst of a “megadrought,” which was the worst the region had seen in over 1,000 years.

Earlier this month, NBC reported that California is drought free for the first time in 25 years. The article makes no mention of the previously predicted “megadrought,” nor does it mention climate change.

Martz said that many of his critics respond to these failed predictions by arguing they weren’t made by scientists in peer-reviewed articles published in journals. Instead, they’re made by politicians or scientists in interviews. But most people don’t get their information from scientific journals. They get it from the media, Martz said.

“That communication is what’s more important in terms of public perception of what science is,” he said.

Listening to the experts

Though it had no scientific basis, there was a widespread belief that global warming could cause the human race to go extinct.

A 2017 survey found that 40% of Americans believed there is a 50% chance of that happening. In fact, the number of people killed by natural disasters has never been lower, a fact largely ignored by the media.

My Mind is Made Up, Don’t Confuse Me with the Facts. H/T Bjorn Lomborg, WUWT

People appear more likely to be influenced by Congresswoman Ocasio-Cortez than the scientific data on deaths from climate-related natural disasters.

Her statement that the world would end in 12 years was actually a misreading of a special report by the Intergovernmental Panel on Climate Change, which predicted that the world would need to cut its carbon dioxide emissions by 40-50% by 2030 and eliminate them entirely by 2050 to keep temperatures from rising more than 1.5 degrees celsius above levels they were at before humans began burning a lot of fossil fuels.

There’s nothing in the report that predicts disaster after crossing that threshold, and some experts are estimating that we have already done so. The report estimates that under the worst-case scenario, the global GDP loses about 2.6%, but it would still be about 10 times larger than it is today. But people didn’t read the report. They just heard Ocasio-Cortez warning of end times.

The report, or at least Ocasio-Cortez’s understanding of it, led her to introduce the ambitious Green New Deal plan, a suite of progressive policies justified as presenting global disaster. It failed to get a single vote when it was brought to the Senate floor for a procedural vote, which would mean, according to Ocasio-Cortez, the world has five years until it ends.

Larry Behrens, communications director for Power the Future, told Just the News that AOC likely spent the seven-year anniversary of her prediction doing exactly what she does any other day.

“Because she knows it was nonsense when she said it, and it’s nonsense now,” he said. “Make no mistake, she’ll join the rest of the eco-left in their convenient climate silence, hoping voters forget their green crusade delivered record energy prices and crushing inflation. On this anniversary, ‘climate’ is the last word AOC and her allies want to utter because midterms are coming, and voters remember exactly who made life more expensive.”

UN Climatists Organized Assault Upon Dissenters

Posted on January 20 by Ron Clutz

Susan Quinn reports in her American Thinker article Climate change advocates at the UN launch new organized assault against free speech and information. Excerpts in italics with my bolds and added images.

For years, climate change “deniers” have been attacked and ridiculed because we don’t believe in the “science” of the left. Yet, invented “science” isn’t science, and too many scientists have cowed to it, incentivized by money or fear of being cancelled, and have climbed on the bandwagon.

More and more people, however, are realizing the scam
that’s been perpetrated and are speaking out.

And now, those who defend climate change caused by humans are furious and alarmed. To discourage dissenters to the progressive narrative, the UN stepped up to stop the “disinformation”, intending to ramp up the war against climate change “deniers”:

At the United Nations Climate Change Conference (COP30), held in Brazil in November 2025, several states endorsed the UN’s ‘Declaration on Information Integrity on Climate Change, an initiative recognizing and trying to combat the rise in climate disinformation in media and politics.’

The UN Declaration is professedly a pledge to ‘fight false information’ about climate change.

At first glance, the Declaration seems fairly innocuous. But if you read it carefully, it clearly condemns those who don’t agree with the UN agenda, demanding censorship of the opposition, largely through the media. Here is one of the listed commitments:

Promote and support the sustainability of a diverse and resilient media ecosystem through adequate policies to enable and ensure accurate and reliable coverage, specially, within this context, on climate and environmental issues, as well as policies on advertising transparency and accountability….

It is not the place of the UN to determine a limitation on discussion of climate change, or create a media network to censor opposing viewpoints or findings. And yet they persist in pursuing this agenda and insist that everyone fall in line. Desiree Fixler, an expert in sustainable finance and investment banking and a former member of the WEF’s Global Future Council on Responsible Investing turned whistleblower, identified the climate change crisis as a hoax:

Fixler, a whistleblower, used to work as a sustainability officer for Deutsche Bank, until she exposed their ‘greenwashing’ and was fired for it. Since then, she has been exposing the climate change narrative and the ‘net zero’ agenda as a scam. In a recent podcast, she explained how the UN and WEF agendas of net zero emissions and ‘stakeholder capitalism’ – a WEF concept – are means to gain control and implement socialism. ‘They’re lying to the public,’ Fixler recently said on the Winston Marshall podcast.

‘They’ve manufactured a climate crisis. There is climate change, but there is no climate crisis… asset managers, consultants, and governments… they’re all in on it because they all profit from it.’

Last year, Stanford University reported on a “rise” in new organizations pushing back against the left’s “climate change crisis” claims:

New Stanford-led research in PLOS One reveals a growing constellation of think tanks, research institutes, trade associations, foundations, and other groups actively working to oppose climate science and policy. The number of countries with at least one such ‘counter climate change organization’ has more than doubled over the past 35 years.

The researchers, in a roundabout way, recognize the aggressiveness of the left’s climate change policies in action to be a major factor for the pushback:

According to the Jan. 22 study, the two factors most closely linked to the formation of at least one counter climate change organization are the strength of a country’s commitment to protecting the natural environment and the level of formal organization in its social sector.

(As it turns out, people are less concerned with some unobservable boogeyman than they are with their utility bills and whether or not they can afford a car.)

An especially frustrating part of this story is that climate change adherents mischaracterize the position of the “deniers” who don’t deny that the climate is changing, but that there is inadequate scientific evidence to suggest that human beings are the source of those changes. This is a critical issue:

How can we consider stopping climate change when
we don’t have scientific data about what causes it?

All the warming since 1940s followed oceanic cyclical events.

Well-known scientists are finally speaking out against the UN censorship initiative:

Prominent voices, including Bjorn Lomborg, have criticized the UN’s stance, insisting that taxpayer-funded climate policies warrant thorough scrutiny, not censorship.

Lomborg contends that the UN’s agenda is not only misguided but runs the risk of economically damaging the very countries it claims to help, as evidenced by countries like Germany facing high energy costs amid aggressive climate goals.

We must take seriously the efforts of the UN to censor scientific debate, because the consequences could be dire:

The implications of this censorship extend far beyond the realm of energy policy, as it threatens foundational principles of democracy and free expression, calling into question the very nature of scientific and academic inquiry.

The controversy and debate must continue!

Canada Climate Policy Built on Corrupt Data

Posted on January 17 by Ron Clutz

Tom Harris and Todd Royal explain why “official” temperature history from Canada government is distorted to invent warming where very little has actually ocurred. Their article: Is Canada basing its climate policies on ‘decision-based evidence-making?’ Excerpts in italics with my bolds and added images.

Politicians want us to believe that they base their decisions on solid, verifiable evidence. “Evidence-based decision-making,” they call it. But what if the decision is made first and then the data is selected, or left uncorrected, in order to support the now politically correct decision? That would then be “decision-based evidence-making.” In other words, a complete corruption of honest decision-making.

It seems that Environment and Climate Change Canada (ECCC) is doing exactly that with the country’s temperature data in order to support the government’s mantra that Canada is “warming twice as fast as the global average.” For, if the one-degree anomalous spike in Canada’s “mean temperature” in 1998 is removed from the data, as even ECCC researchers themselves advocated previously should be done to preserve data integrity in cases like this, then Canada is not warming at all and much of the $200 billion spent on the climate file by the federal Liberal government since 2015 is a complete waste.

In 2021, Dr. Joseph Hickey, a data scientist with a PhD in Physics, specializing in complexity science, then an employee of the Bank of Canada, alerted ECCC to this one-degree jump in temperature data across much of Canada, and asked for an explanation. The below graphs of mean, maximum and minimum temperatures constructed with data from three Canadian cities—Moncton (on which Hickey illustrates the step change with red lines), Ottawa and Montreal—are samples of those created by Hickey using ECCC data downloaded on November 11, 2025, data that is the same as that he sent to ECCC researchers as an attachment to his email of June 24, 2021.

Ignoring their previous position about the need to remove such sudden discontinuities from the data, ECCC staff had little to say and left the anomaly in the record, asserting that it was “probably” a real sudden change in temperature.

Making matters worse, another Bank of Canada employee, economist Julien McDonald-Guimond, had already alerted ECCC by email on December 7, 2020, that he had found more than 10,000 instances of days for which the daily minimum temperature was greater than the daily maximum temperature. Again, ECCC staff had no reasonable justification.

With the Canadian government no longer his employer, so Hickey is now free to tell us all what has been going on behind the scenes. This Hickey did on December 23, 2025, when he published the blockbuster report “Artificial stepwise increases in homogenized surface air temperature data invalidate published climate warming claims for Canada.”

Dr. Hickey shows that, if you apply ECCC’s trend analysis method to their data, you find an increase of 1.74° C (which is statistically significant) from 1948 to 2018. And then, he tells us, if you correct for the one-degree step increase in 1998, you find only a 0.29°C rise. That small change “is indistinguishable from zero,” explains Hickey. “There is no evidence of warming.”

Figure 7: Map showing Sr calculated using Tmean, for the break year 1998 with two five-year windows (1993-1997 and 1998-2002) for the 302 3rd generation AHCCD stations with sufficient data. Circle radius is proportional to the absolute value of Sr. Circle colour indicates Sr ranges as follows: blue: Sr < 0; black: 0 ≤ Sr ≤ 1; red: Sr > 1. Moncton, NB (Sr = 2.74) is indicated with a green circle, for reference.

In Figure 7, AHCCD stations with Sr < 0 are coloured blue, while black indicates 0 ≤ Sr ≤ 1, and red indicates Sr > 1. The AHCCD records with the largest stepwise increases at 1998 are located in Eastern and Central Canada (including the stations listed in Table A), and there are many records with discernible steps at 1998 in the Prairies (provinces of Manitoba, Saskatchewan, and Alberta) and the north of the country. British Columbia remains the main outlier, with most ofits AHCCD stations having no discernible steps at 1998.

Figure 8: Map of trend in Tmean over the period 1998-2018, for the 3rd generation AHCCD stations with sufficient data, calculated using linear least-squares fitting. Circle radius is proportional to the absolute value of the trend. Blue circles correspond to negative trends (trend < 0) and red circles to positive trends (trend > 0).

In Figure 8, the trend for a particular Tmean record is equal to the slope (°C/year) from a linear least-squares fit to its data for 1998-2018, times 21 years. An AHCCD station was considered to have sufficient data if its record had at least 350 days of non-missing daily data per year for every year from 1998 2018. Approximately two thirds of the AHCCD records with sufficient data have negative trends for 1998-2018 using linear least-squares fitting.

Summation

This report demonstrates Environment Canada’s dismissive response to being alerted to a large, apparently non-climatic artifact in its flagship temperature time-series product, an artifact which could, on its own, be responsible for essentially all of the calculated warming for many Canadian locations over the past six or seven decades.

The said apparent artifact, referred to as the “1998 step-increase feature” in this report, is a stepwise increase of approximately 1°C in magnitude occurring at 1998 in the annual mean time-series of daily maximum, minimum, and mean temperatures for many stations across Canada in Environment Canada’s Adjusted and Homogenized Canadian Climate Data (AHCCD).

HadCRUT5 temperatures Predict ML CO2

Posted on January 14 by Ron Clutz

Recently another researcher, Bernard Robbins, found similar causation between ML CO2 and SST fluctuations reported by NOAA Global SST dataset. See More Evidence Temperatures Drive CO2 Levels, Not the Reverse.

Previously I have demonstrated that temperature changes are predictive of changes in atmospheric CO2 concentrations. That includes the remarkable GMT spike starting in January 2023 and rising to a peak in April 2024, then dropping down to end of 2025. The most recent study was Yearend 2025, Cooling Temperatures Reducing CO2 Rise employing Mauna Loa CO2 data and UAH GMT data.

I noticed at WUWT my post was included in Weekly Climate and Energy News Roundup #674 with a comment attached: [SEPP Comment: The time period of the claimed lower CO2 rise is too short to be clear.] Now if that is referring to a table detailing the two variables during 2024 and 2025, I can understand it. But it also disregards the complete study covering UAH satellite temperature changes clearly leading Mauna Loa CO2 changes over a period of 45 years.

Along with some comments on my blog, I wondered whether the entire ML record of CO2 levels could be predicted from global temperature changes, which would require a GMT dataset covering 1959 to the present. This post shows that HADCRUT5 qualifies and indeed confirms other studies by researchers. I was particularly interested in the lack of warming in the 1960s and 70s, before the satellite temperature data became available.

The answer is yes: Just as temperature spikes result
in a corresponding CO2 spike as expected. Cooler temperatures
are predictive of lower CO2 levels.

Above are HadCRUT5 temperature anomalies compared to CO2 monthly changes year over year during 65 years from 1959 to present.

Changes in monthly CO2 synchronize with temperature fluctuations, which for HadCRUT5 are anomalies referenced to the 1961-1990 period. CO2 differentials are calculated for the present month by subtracting the value for the same month in the previous year (for example December 2025 minus December 2024). Temp anomalies are calculated by comparing the present month with the baseline month. Note the recent CO2 upward spike and drop following the temperature spike and drop.

The final proof that CO2 follows temperature due to stimulation of natural CO2 reservoirs is demonstrated by the ability to calculate CO2 levels since 1959 with a simple mathematical formula:

For each subsequent year, the CO2 level for each month was generated

CO2 _{this month this year} = a + b × Temp _{this month this year} + CO2 _{this month last year}

The values for a and b are constants applied to all monthly temps, and are chosen to scale the forecasted CO2 level for comparison with the observed value. The values for scaling HADCRUT5 and MLCO2 were “a” = 1.2 and “b” = 1.52 Here is the result of those calculations.

In the chart calculated CO2 levels correlate with observed CO2 levels at 0.9992 out of 1.0000. This mathematical generation of CO2 atmospheric levels is only possible if they are driven by temperature-dependent natural sources, and not by human emissions which are small in comparison, rise steadily and monotonically. For a more detailed look at the recent fluxes, here are the results since 2015, an ENSO neutral year.

For this recent period, the calculated CO2 values match well the annual lows, while some annual generated values of CO2 are slightly higher or lower than observed at other months of the year. Still the correlation for this period is 0.98

Footnote:

Hadcrut v5 offers a choice of two GMT data sets, one which infills grid cells lacking data and one which does not, compiling data only from cells with sufficient data. The analysis here shows data from Hadcrut 5 Not Filled In, though results from the Filled In dataset are virually the same with a slight upward bias. The overall lower anomalies in UAH are due to a later baseline, 1991 to 2020.

Key Point

Changes in CO2 follow changes in global temperatures on all time scales, from last month’s observations to ice core datasets spanning millennia. Since CO2 is the lagging variable, it cannot logically be the cause of temperature, the leading variable. It is folly to imagine that by reducing human emissions of CO2, we can change global temperatures, which are obviously driven by other factors.

Background Post

Temps Cause CO2 Changes, Not the Reverse. 2024 Update

Summary:

The massive fluxes from natural sources dominate the flow of CO2 through the atmosphere. Human CO2 from burning fossil fuels is around 4% of the annual addition from all sources. Even if rising CO2 could cause rising temperatures (no evidence, only claims), reducing our emissions would have little impact.

Atmospheric CO2 Math

Ins: 4% human, 96% natural
Outs: 0% human, 98% natural.
Atmospheric storage difference: +2%
(so that: Ins = Outs + Atmospheric storage difference)

Balance = Atmospheric storage difference: 2%, of which,
Humans: 2% X 4% = 0.08%
Nature: 2% X 96 % = 1.92%

Ratio Natural : Human =1.92% : 0.08% = 24 : 1

December 2025 All Ocean SSTs Cool to Mean

Posted on January 9 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.

This December 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 December 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 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 December the Global anomaly exactly matched the mean for this period, with all regions converging on that value, led by a 6 month drop in NH. Essentially, all the warming since 2015 is now gone.

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, continuing February through April 2025, with little change in May,June and July despite upward bumps in NH. Now temps in all regions have cooled led by NH from August through December 2025.

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. In October there was an unusual upward spike, now reversed down to match September 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 0.18. The orange line the average 1982-2025, value 0.41 also for the period 1997-2012. The red line is 2015-2025, value 0.74. 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

UAH Cooling Everywhere December 2025

Posted on January 7 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

December 2025 UAH Temps: Cooling Everywhere Led by SH

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 December 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 October 2025 Ocean SST Cools to Mean 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 November and December 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 December 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 November/December all regions are cooler, led by a sharp drop in SH bringing the Global ocean anomaly down to 0.02C. 1/4 of what it was in April 2024.

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 December 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. A remarkable spike in October was completely reversed in November/December, along with NH dropping sharply bringing the Global Land anomaly down to 0.52C, half of its peak value of 1.17C 09/2024.

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 -0.02 for 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.

Yearend 2025, Cooling Temperatures Reducing CO2 Rise

Posted on January 6 by Ron Clutz

2025 ended with a steadily declining rate of rising CO2 in the atmosphere following a 20 month cooling since April 2024, peak of an unusual and unexplained warming spike. Historical records show that around 1875 was the coldest time in the last 10,000 years. That was the end of the Little Ice Age (LIA), and since then temperatures have warmed at an average rate of about 0.5C per century. The recovery of the biosphere and ocean warming resulted in rising levels of CO2 in the atmosphere.

Syun-Ichi Akasofu, founder of the University of Alaska Fairbanks’ Geophysical Institute reported on this pattern in 2009.

At times, there are warming spikes, in the 1930s and 40s for example, and the rate of rising CO2 goes up. At other times, such as 1950s and 60s, temperatures cool, and rising CO2 slows down. More recently, in 2023 and 24, we saw temperatures spike up before falling back down in 2025. [Note: A study of ocean biochemistry processes confirms that since the end of the LIA rising temperatures have been accompanied by rising CO2 at a rate of ~2 ppm per year. [ See: Slam Dunk: Δtemp Drives Δco2, Ocean Biochemistry at Work ]

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.

Previously I have demonstrated that changes in atmospheric CO2 levels follow changes in Global Mean Temperatures (GMT) as shown by satellite measurements from University of Alabama at Huntsville (UAH). A link to that background post is provided later below.

My curiosity was piqued by the remarkable GMT spike starting in January 2023 and rising to a peak in April 2024. GMT has declined steadily, and now 20 months later, the anomaly is 0.30C down from 0.94C. I also became aware that UAH has recalibrated their dataset due to a satellite drift that can no longer be corrected. The values since 2020 have shifted slightly in version 6.1, as shown in my recent report UAH Ocean Stays Cool, SH Land Warms, October 2025, The data here comes from UAH record of temperatures measured in the lower troposphere (TLT).

This post updates the analysis with the complete observations for 2025, testing the premise that temperature changes are predictive of changes in atmospheric CO2 concentrations. The chart at the top shows the two monthly datasets: CO2 levels in blue reported at Mauna Loa, and Global temperature anomalies in purple reported by UAHv6.1, both through December 2025. Would such a sharp increase in temperature be reflected in rising CO2 levels, according to the successful mathematical forecasting model? Would CO2 levels decline as temperatures dropped following the peak?

The answer is yes: that temperature spike resulted
in a corresponding CO2 spike as expected.
And lower CO2 levels followed the temperature decline.

Above are UAH temperature anomalies compared to CO2 monthly changes year over year.

Changes in monthly CO2 synchronize with temperature fluctuations, which for UAH are anomalies referenced to the 1991-2020 period. CO2 differentials are calculated for the present month by subtracting the value for the same month in the previous year (for example December 2025 minus December 2024). Temp anomalies are calculated by comparing the present month with the baseline month. Note the recent CO2 upward spike and drop following the temperature spike and drop.

The table below shows clearly the pattern of observed temperatures declining along with declining rates of rising observed CO2. The CO2 rate peaked at 4.41 ppm, then declined over the next 21 months to 2.09 ppm, nearly the baseline rate since the LIA. There are fluctuations in the CO2 monthly response since the differential is influenced by the previous year as well as current year. By 2025/12, the rate of 2.09 ppm was less than half the peak rate of 4.41 ppm.

Month	temperature anomaly	co2 Diff. from previous year
2024\1	0.79	3.32
2024\2	0.86	4.23
2024\3	0.87	4.41
2024\4	0.94	3.14
2024\5	0.78	2.87
2024\6	0.70	3.25
2024\7	0.74	3.72
2024\8	0.75	3.31
2024\9	0.80	3.53
2024\10	0.73	3.56
2024\11	0.64	3.39
2024\12	0.62	3.54
2025\1	0.46	3.85
2025\2	0.50	2.54
2025\3	0.58	2.77
2025\4	0.61	3.13
2025\5	0.50	3.61
2025\6	0.48	2.70
2025\7	0.36	2.32
2025\8	0.39	2.49
2025\9	0.53	2.34
2025\10	0.53	2.49
2025\11	0.43	2.61
2025\12	0.30	2.09

The final proof that CO2 follows temperature due to stimulation of natural CO2 reservoirs is demonstrated by the ability to calculate CO2 levels since 1979 with a simple mathematical formula:

For each subsequent year, the CO2 level for each month was generated

CO2 _{this month this year} = a + b × Temp _{this month this year} + CO2 _{this month last year}

The values for a and b are constants applied to all monthly temps, and are chosen to scale the forecasted CO2 level for comparison with the observed value. Here is the result of those calculations.

In the chart calculated CO2 levels correlate with observed CO2 levels at 0.9988 out of 1.0000. This mathematical generation of CO2 atmospheric levels is only possible if they are driven by temperature-dependent natural sources, and not by human emissions which are small in comparison, rise steadily and monotonically. For a more detailed look at the recent fluxes, here are the results since 2015, an ENSO neutral year.

For this recent period, the calculated CO2 values match well the annual highs, while some annual generated values of CO2 are slightly higher or lower than observed at other months of the year. Still the correlation for this period is 0.9942.

Key Point

Background on Analytics and Methodology

Temps Cause CO2 Changes, Not the Reverse. 2024 Update

Slam Dunk: Δtemp Drives Δco2, Ocean Biochemistry at Work

Posted on December 30 by Ron Clutz

Peter Smith explains in his Quadrant article Shunned by Sanctitudinous Science. Excerpts in italics with my bolds and added images. Synopsis of Ivan Kennedy paper follows later.

When coffeeing with a group of conservative friends as I do on Fridays, one of our number, Professor Emeritus Ivan Kennedy, said something to the effect that there were no scientific alternative theories to the IPCC’s explanation of global warming except for his.

I was taken aback. Surely, even within my limited knowledge, William Happer (Princeton) and Richard Lindzen (MIT) hypothesise that the effect of CO2 on warming progressively declines. Nobel Prize winner Dr John Clauser hypothesises that reflective cumulus clouds created by water vapour, engendered by modest warming, act as a thermostat to keep global temperatures down. You can read about it here if you wish. So what is going on?

Let me start by dismissing the canard that global warming is an invention. Sure, maybe the so-called ‘homogenisation’ of past land and sea temperature data has artificially steepened the warming record since the 1940s. But, for all that, the NOAA satellite data since the end of 1979 shows that the temperature in the sub-troposphere has trended up by about 0.7⁰C between December 1979 and December 2024. As this data has been compiled by Roy Spencer and John Christy (sceptical scientists) at the University of Alamba in Huntsville, we can safely assume it is trustworthy.

So the climate has warmed. Now should come the scientific fun.
Competing theories jostling to best explain the data. No such fun.
Blaming exploitative Western man has proved to be a sacrosanct hypothesis.

Sacrosanctity and science don’t mix. Many past theories propounded by scientific giants have eventually failed the test: Ptolemy’s geocentric theory of the solar system; Aristotle’s theory of gravity, even Newton’s. Yet a tenuous theory of the climate concocted by relative mediocrities, which hasn’t come close to accurately predicting global temperatures, is holy writ. Risible, except that political and celebrity buy-in is undoing progress wherever it results in the replacement of reliable with unreliable energy. Think of Australia as a quintessential case study.

Happily, despite powerful and well-funded forces out to cancel dissenters, maverick scientists keep on stirring the pot. Which brings me back to Prof. Kennedy and his collaborators. Their hypothesis can be found here. In lay terms it goes like this:

The increased concentration of CO2 in the atmosphere since the 1960s has been caused by warming not the reverse. Other things equal, emissions by mankind of CO2 are all absorbed by the land (hence the greening) and by the oceans. Thus, on this account, there is no material net increase of CO2 in the atmosphere from fossil fuel emissions. Ergo, such emissions cannot be the cause of warming. It is true that warming has occurred, and that atmospheric CO2 has risen. The underlying chain of events is as follows.

Warming, perhaps through solar activity, promotes the precipitation of calcium carbonate (limestone) in surface sea water, absorbing CO2 from the atmosphere in the process. In turn, the absorbed CO2, magnified by calcium carbonate precipitation, acidifies surface sea water. The acidification then results in the emission of CO2 into the atmosphere in autumn and winter. This emission of CO2 is greater than the absorption, precisely because of the continuing acidification in the warming water.

In the end we see increased atmospheric CO2 and warming.
It is easy to draw the wrong conclusion. Indeed, the IPCC has done so.

I see the point about Kennedy’s hypothesis being singularly different from other alternative hypotheses. Lindzen’s and Happer’s hypothesis, and Clauser’s, embrace the foundational proposition of the received theory, albeit in muted form. Namely, that man-made CO2 is adding to atmospheric CO2, thereby having a greenhouse effect. Kennedy’s hypothesis does not embrace that proposition.

Whether Kennedy is right (or Lindzen and Happer or Clauser) is by the way. Alternative hypotheses are in the skeptical scientific tradition of searching for theories which better explain the facts than does the received theory. That is particularly important in this case. The received theory is upending life as we know it, while being shielded from rival theories by money, politics and pseudo-religiosity.

The paper by Ivan Kennedy et al. is A Thermal Acid Calcification Cause for Seasonal Oscillations in the Increasing Keeling Curve . Synopsis below with excerpts in italics with my bolds and added images.

Abstract:

Why do atmospheric carbon dioxide levels rise and fall seasonally measured on Mauna Loa? This study explores the thermal acid-calcification (TAC) hypothesis, suggesting that seasonal temperature shifts in surface seawater trigger acid pH-driven CO₂ emissions caused by calcification. Using oceanographic data, we modeled how temperature affects dissolved inorganic carbon including CO₂, bicarbonate, and carbonate.

Our findings reveal that warming waters absorb atmospheric CO2 by promoting calcium carbonate formation, acidifying seawater and boosting CO₂ release to the atmosphere in late autumn and winter, when atmospheric CO₂ becomes highest. The model predicts a net annual CO₂ rise of 2 ppmv, driven by calcification rather than land-based processes. Seasonal pH swings of 0.04 units corroborate this mechanism. The TAC hypothesis indicates that continued ocean warming, not just fossil fuels, contribute to rising CO₂ levels, calling for deeper investigation into marine carbon dynamics.

The Keeling Curve for atmospheric pCO2 in parts per million by volume

Fig. 1. The Keeling curve of atmospheric CO2 partial pressure at 3200 m on Mauna Loa, Hawaii. Data from Dr. Pieter Tans, NOAA/ESRL and Dr.Ralph Keeling, Scripps Institution of Oceanography.CC BY-SA

The very stuff of plant life on Earth in photosynthesis as well as in the structural basis of all living creatures, we are told by the United Nations Intergovernmental Panel on Climate Change (IPCC) (2) that the continuing rise of CO2 in the Keeling curve shown in Figure 1 now threatens global catastrophe from global warming. Such a paradoxical contrast for good and bad lacks credibility, given the longevity of life on Earth.

Transfers of CO2 out of the ocean surface in winter versus that entering in summer

We propose that a quasi-equilibrium exists between a falling pH value in surface water, favoring CO2 emisssion. Falling pH values in the surface water of the oceans have been an enigma, invisible to scientific view until recently after the year 2000. Our logic is supported in our articles (3, 4) where we describe the basis for the thermal acid-calcification (TAC) hypothesis, also using data cited from others. Acidic calcification is thermodynamically favored in warming surface seawater, particularly in northern oceans in spring and summer with shallow mixing zones and higher temperature ranges. This raises the fugacity or potential pressure of CO2 in seawater to its peak value in summer when the pCO2 in air is minimal, causing its forceful emission into air in the next autumn reaching a maximum pCO2 in late winter (Fig. 1, seasonal variation insert).

Fig. 2. Thermal acid-calcification model for seasonal and longer-term generation of the Keeling curve. The Thermal model (3), showed calcification is favored by increase in temperature giving decreasing pH values in summer, reversing in cooler conditions to more alkaline pH in winter. Note that precipitation of CaCO3 in spring to summer removes CO32- that is replaced from HCO3 – with more acidity, provided by absorption of CO2 from air up to October. However, as the pH falls the steady state concentration of [CO2} increases favoring photosynthesis.

Acid calcification is essential for phytoplankton

Any process of strong acidification of surface seawater will raise the concentration of carbon dioxide as [CO2] available to phytoplankton for photosynthesis. Bicarbonate cannot be a direct substrate for photosynthesis although the presence of the enzyme carbonic anhydrase speeds up its interconversion with CO2. Our published modeling analysis confirmed that CaCO3 precipitation is strongly favored by warmer temperatures (Table 1). Indeed, all the reaction equilibria in seawater are displaced to the right in Figure 2 acidifying the water, although the equilibrium between CO2 concentration and pCO2 in air favors a lower concentration [CO2} in water in summer, compared to winter, when it is greatest. Our results even confirmed that the formation of CaCO3 as calcite is predicted to increase in summer as water becomes warmer (Table 1b).

Thus, we can expect more limestone formation in summer if the carbonate concentration reaches a sufficient level, favored by added warming. The decline in average pH values in surface seawater to about 8.05 from pH 8.20 could explain the increased pCO2 in the atmosphere of 140 ppmv since 1800 as a matter of dynamic equilibrium. Caused by calcification, this would require a simultaneous equivalent deposition of limestone as sediment, though only an increase of about 10 μmoles per kg of surface seawater, or a net 1 mg per kg each year. This is a key prediction for experimental testing of the TAC hypothesis.

This fully reversible calcification equation moves towards acidification in summer and reverses to alkalinization in winter. The psi factor is a variable function of the range of seasonal changes in temperature. However, the greatest thermodynamic potential to emit CO2 in seawater by acidification of bicarbonate (HCO3-) is when the pH value is lowest, the conversion of bicarbonate to CO2 generating the greatest difference between CO2 fugacity in seawater and that in air in midsummer in northern hemisphere waters. The seasonal variation near Mauna Loa in atmospheric pCO2 is about 6 ppmv whereas the long term increase in the Keeling curve year by year is one third of this, about 2 ppmv suggesting that in spring and summer the CO2 absorbed in about 2 ppmv, less than that emitted in autumn and winter.

Fig. 5. Rates per square meter in global carbon cycling between land water, the atmosphere, and the ocean, illustrating the pH-acidification hypothesis. Emissions and absorptions shown are average moles per square meter of the Earth, for a mixing ratio of 420 ppmv in 2021 shown in the central column bridging land and ocean. The land acidification values are derived elsewhere (11), assuming photosynthesis is equal to respiration. The terrestrial area of Earth is 1.48×1014 m-2 , the ocean’s area is 3.62×1014 m2 , 5.101 x1014 m2 in total., represented as a mean value in the central air column.

Discussion

Limestone as a product of calcification is regarded as a biogeochemical product, given that phytoplankton and other marine organisms enhance its rate of production, if nutrients are available (3). In particular, the extracellular carbonic anhydrase apparently speeds the reversible dehydration of CO2, forming bicarbonate and hydrated hydrogen ions (H+) controlling pH. This article emphasizes that the reversible dehydration of CO2 in surface seawater allowing transfer between aqueous and gaseous phases is most rate limiting of all, that carbonic anhydrase may even assist in autumn and winter, transferring CO2 to the atmosphere.

More significantly for managing climate change, if fossil fuel emissions are being largely absorbed by sequestration into the ocean surface and by ‘greening’ photosynthesis on land and in the ocean (11), the implications of this aspect of the TAC hypothesis for carbon-zero policies and renewable energy are profound.

The thermal acid-calcification hypothesis predicts that global warming
acidifies the ocean surface by increasing calcification causing
pCO2 to increase, independently of fossil emissions.

Furthermore, this represents a striking illustration of the Le Chatelier principle, the carbon cycle on Earth responding intelligently to changing climate. The hope that carbon dioxide removal as sequestration (14), either biologically, chemically or geologically, by burial after capture, will prove futile.

The uncertainty of the current IPCC paradigm regarding climate change and the role of fossil emissions of CO2 in warming is large, lacking scientific evidence. A plausible alternative hypothesis offered here as the true cause of the increasing Keeling curve needs to be investigated urgently. This new model would still give predictively increasing emissions from the ocean in the complete absence of fossil fuel emissions because the acidification from calcification is purely a function of surface warming, from whatever cause.

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Science Matters

Reading between the lines, and underneath the hype.

The Hottest Year Shell Game

The Distorted Reporting of Global Average Temperature 2025 and its relevance to the Paris Agreement

See Also:

Shortage of Climate Comedians

Al Gore’s “Inconvenient Truth” Decrepit at Age 20

Stubborn ice

Uncertainty and nuance

Listening to the experts

UN Climatists Organized Assault Upon Dissenters

Canada Climate Policy Built on Corrupt Data

Summation

HadCRUT5 temperatures Predict ML CO2

Footnote:

Key Point

Background Post

Summary:

Atmospheric CO2 Math

December 2025 All Ocean SSTs Cool to Mean

Contemporary AMO Observations

Curiosity: Solar Coincidence?

UAH Cooling Everywhere December 2025

December 2025 UAH Temps: Cooling Everywhere Led by SH

The Bigger Picture UAH Global Since 1980

Yearend 2025, Cooling Temperatures Reducing CO2 Rise

Key Point

Background on Analytics and Methodology

Slam Dunk: Δtemp Drives Δco2, Ocean Biochemistry at Work

Abstract:

The Keeling Curve for atmospheric pCO2 in parts per million by volume

Transfers of CO2 out of the ocean surface in winter versus that entering in summer

Acid calcification is essential for phytoplankton

Discussion

See Also

Key Point