Climate Factors | Science Matters

SH and Tropics Lead UAH Cooling June 2025

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.

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 ~60 ppm, a 15% 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 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

June 2025 SH and Tropics Lead UAH Temps Lower

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 June 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 behind the update from HadSST4. I posted recently on SSTs June 2025 Ocean SSTs: NH Warms, SH Cools.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. Then land air temps, especially NH, dropped in February and recovered in March. Now in June SH land dropped markedly and NH land down slightly, while ocean air temps rose slightly in NH, offset by cooling in SH and Tropics.

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 June 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 June Global ocean air anomaly is little changed despite a slight rise in NH.

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 June 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. In March that drop reversed with both NH and Global land back to January values, holding there in April. In May sharp drops in NH and Tropics land air temps pulled the Global land air temps back down close to February value. In June the Global land air drop was significant, down from 0.67C to 0.55C despite a small rise in the Tropics.

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 -0.03, 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. February went down to 0.5C, then back up to 0.6C in March and April driven by the bounce in NH land air temps, followed by May’s return to 0.5C, and June slightly lower at 0.48C.

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

Note on Ocean Cooling Not Yet Fully Appearing in UAH Dataset

The above chart shows sea surface temperature anomalies (SSTA) in the North Atlantic 0 to 60N. The index is derived from ERSSTv.5 by subtracting the global anomalies from the North Atlantic anomalies, the differences as shown in the chart. The baseline of 0.0C is the average for the years 1951 to 1980. The mean anomaly since 1980 is in purple at 0.33C, and persisted throughout up to 2018. The orange line is the average anomaly in the the last six years, 2019 to 04/2025 inclusive, at 0.84C. The remarkable spikes in 2023 and 2024 drove that rise to exceed 1.4C, which has been cut in half over the last 10 months. As Dr. Humlum observed, such oceanic changes usually portend air temperature changes later on.

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.

Climate Model Assumptions Contrary to Balloon Data

Posted on July 21 by Ron Clutz

Recently Michael Connolly presented the evidence contradicting assumptions built into GCMs (Global Climate Models). This post consists of the exhibits he used, and additional Connolly comments in italics from a similar talk this month to Doctors for Disaster Preparedness. (Video embedded later in post.)

Michael Connolly:

I’m an engineer and a scientist. As an engineer, I use computer models to design and make things. As a scientist, I look at the data to see if my computer models are correct. So, what we did at the center for environmental research and earth sciences (CERES) is that we looked at the data from 20 million radio balloons.

We then asked, can we look at this data and see how we can use it to check the computer models? And we found there’s two types of balloons. One: the average weather balloon does about a 100 measurements as it goes up to the stratosphere. But the ones which measure ozone do a measurement about once every second. So you have maybe four or 5,000 measurements on each sample. But all of the climate models, and by the way, nobody in the climate model community bothered to check the data to see if their models were correct, which I find very bizarre. But what all of the model community do is they divide the earth into a number of little boxes. So on a horizontal scale the boxes are about 1,000 mi long and on a vertical scale they’re about less than a mile in height.

They then make a number of assumptions about how the air behaves within each of these boxes. So their first assumption is that the air in each box is in a state which we call thermodynamic equilibrium. which I’ll explain in a few minutes. So they assume that on a horizontal scale the air in a box is in equilibrium over a distance of a 1,000 miles. But on a vertical scale only in equilibrium for slightly less than a mile.

And they also assume that the different boxes are not in thermodynamic equilibrium with each other. Because if it turns out that the boxes are in thermodynamic equilibrium with each other, all of the assumptions of the climate models collapse because Einstein and his co-authors over a 100 years ago showed that if a system was in thermodynamic equilibrium, if you put in a greenhouse gas into that system, it would absorb more energy. But if it’s in thermodynamic equilibrium, it emits more energy. So increasing the level of greenhouse gases will increase the rate of absorption but also increase the rate of emission. So there’s no net change due to the radiation. So if it turns out that the assumption that the the different boxes aren’t in thermodynamic equilibrium is false, then the whole theory of man-made global warming collapses.

So how do we know if something is in thermodynamic equilibrium or not? Well, what you do is you take a system and you do all the measurements of the different parameters involved and if you can describe the system in what’s called an equation of state with using these parameters, then we say the state is in thermodynamic equilibrium. So in other words, obeying an equation of state is one side of the coin of being in thermodynamic equilibrium. They’re both different sides of the same coin.

So for the air, the equation of state is this. It’s called the ideal gas law. And this is the equation that’s used by the climate modelers in treating the different boxes as being in thermodynamic equilibrium. You can see down there it tells you the relationship between the different parameters, but it doesn’t tell you how much energy it would take to change the temperature of a system. For that you need to know the heat capacity of the system. And it doesn’t tell you anything about potential energy. In other words, if I take a cubic meter of air and lift it up and keep it at the same temperature and pressure, it would obey the same equation, but it would have gravitational potential energy because it takes energy to lift it up. That’s not reflected in the equation of state.

As a chemist I thought there was something dead obvious to do. The equation of state can be rewritten in a different form called the molar density form, and this form has been used by chemists for hundreds of years to determine the molecular weight of new gases. So we asked what happens if we describe the atmosphere in terms of molar density form instead of the energy form? We were the first and still the only people to have done this.

When we did that we got a big surprise. We found that if you plot the molar density versus pressure you get these two straight lines. Now this means that the atmosphere in the troposphere, that’s the lower bit, is obeying an equation of state. So that means it’s in thermodynamic equilibrium. And when you get to the tropopause it turns into another straight line. Now this is quite common in studying materials. If you can describe it in terms of one equation of state and then it changes into another equation of state, we call it a change of phase. For example, you can describe water using the gaseous water using the gas laws, but then when it turns into liquid water, you have to use a different equation of state.

Now we studied all the different weather balloons from all around the world and we found that this phenomenon occurred in all of them. The only difference was that in the tropics the change of phase occurred at a higher altitude and in the Arctic and polar regions it occurred at a lower altitude. So, when we were here in Tucson 5 years ago, we made a video for the entire year of all of the radio balloon data for Tucson for 2018. And the reason for this video is that looking at a static graph like that, you don’t see any changes. Now, in the models that they’re using, the different boxes are isolated from each other, if you put energy into one of the boxes, it would kind of stay there. But if they’re in thermodynamic equilibrium, you put energy into one box, then all of the boxes will change because all of the energy will be distributed throughout the system. When you look at the video, the behavior of the boundary layer position moves up and down.

But also the temperature: if it moves to the right, the temperature is increasing. If it moves to the left, the temperature is decreasing. And what you will see once you watch the video, it’s all synchronized. In other words, if a change occurs, if the troposphere is warming up and the temperature is moving to the right, the tropopause moves down, the tropopause moves in the opposite direction. So in other words, when the troposphere heats up, the tropopause cools down. when the troposphere cools down the tropopause heats up and it does so in a synchronized way. So that synchronization shows that it’s thermodynamically connect connected. The idea that all of these boxes are not in thermodynamic equilibrium is contradicted by this data. [The referenced video starts at 10 minutes into the embedded presentation below.]

So that’s the first assumption. Now looking at the second assumption.
Back in the day, 18th century or something, Hadley was looking to explain the trade winds. So he came up with this idea of what happens: The very hot temperatures landing on the equator heated up the atmosphere. here and this hot air then rose up. Then as it rose up it started to move towards the poles and as it moved towards the poles it cooled down and you got this circular phenomenon. They came up with three different types of circular cells: the Hadley cells; the Ferrel cells and the Polar cells. But all of these this theoretical stuff was based on ground measurements.

And again uh nobody bothered to check whether this is true or not. So I’ll just show how we checked it. But first of all I just want to explain what’s meant by mass flux. So if you take a square meter and you measure the air flowing through it and what weight of air that is the mass flux. So in the weather balloons they give you the speed of the air and they give you the direction in which it’s it’s going. So you can use this to calculate the mass flux. So we said fine. So can we use this to check the idea of the Hadley cells and it turns out that you can. So we did and we published a paper two years ago.

We found first of all if you take a balloon and you launch it up through one of these cells then if Hadley is correct you would expect the hot air was rising here in the tropics and that drags in the air from the colder regions and then it hits the tropopause. Now, when Hadley came up with the idea, nobody knew the tropopause existed, and it’s only 30 years before I was born that it was actually discovered. So, that’s telling something about my age.

Anyway, if you send a balloon up through the atmosphere, you would expect the mass flux flow to flow in that direction down at the lower levels. And then as you go up at some stage it would shift over and start going in the opposite directions. So since that was available that mass flux we could measure from the balloon data we did that and we got a surprise.

There was absolutely no circulation patterns at all. Instead what the atmosphere was doing. So if we point here you can see these ones are the lower ones. So you have the direction the north south direction of the mass flux. These are the ones at the lower half of the troposphere. These are the ones in the opposite half of the troposphere.

For a Hadley cell you would expect these ones to be flowing in the opposite direction to these ones. But instead what we find is they all flow in the same direction. And in a very unusual pattern. What happens is here it’s flowing south then the atmosphere slows down over a couple of days goes back and forth and so on. So instead of this circular pattern what’s happening is the whole atmosphere is moving like a giant pendulum back and forth. So we have the atmosphere going one way, then after a few days it turns around and comes back in the opposite direction. And this is for Iceland but we found the exact same thing occurred for all the different stations.

So in that published paper we we took a station from each of the different five climate types and we found the exact same sort of thing happened. Now people said: okay so maybe it’s going back and forward on a daily basis but over a period of a year it might average out. So we average the data over the five years for each of the stations.

And since we published that paper, we’ve analyzed over 250 of the weather stations in the tropics. And we found for these 82% of them are Hadley. 73 in the northern hemisphere. So the majority are not Hadley cells. And in the southern hemisphere they’re equally balanced. But the problem with even the ones that were Hadley cells is you can see here the mass flux grow flowing in this direction the area under the curve is not the same as the one up above. And if it was a proper Hadley cell, they’d have to be the same. So what we found is for none of them this worked out. So they don’t exist, right?

June 2025 Ocean SSTs: NH Warms, SH Cools

Posted on July 17 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.

HadSST is generally regarded as the best of the global SST data sets, and so the temperature story here comes from that source. Previously I used HadSST3 for these reports, but Hadley Centre has made HadSST4 the priority, and v.3 will no longer be updated. HadSST4 is the same as v.3, except that the older data from ship water intake was re-estimated to be generally lower temperatures than shown in v.3. The effect is that v.4 has lower average anomalies for the baseline period 1961-1990, thereby showing higher current anomalies than v.3. This analysis concerns more recent time periods and depends on very similar differentials as those from v.3 despite higher absolute anomaly values in v.4. More on what distinguishes HadSST3 and 4 from other SST products at the end. The user guide for the current version HadSST4.1.1.0 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 HadSST4 starting in 2015 through June 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 last year, ~0.3° higher than the 2015 peak. Then NH started down autumn 2023, followed by Tropics and SH descending 2024 to the present. After 12 months of cooling in SH and the Tropics, the Global anomaly came back down, led by NH cooling the last 8 months from its 1.3C peak in August, down to 0.8C in March and April. Remarkably, April 2025 SST anomalies in all regions and globally are the coolest since March 2023. May showed little change in the Global anomaly, while in June declines in SH along with the Tropics mostly offset an upward bump in NH.

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 and June despite upward bumps in NH.

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 was holding at 1.4C before declining. 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 is headed sharply downward, well below the previous two years, now in May and June aligning with 2010.

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

The purple line is the average anomaly 1980-1996 inclusive, value 0.17. The orange line the average 1980-2024, value 0.4, also for the period 1997-2012. The red line is 2013-2024, value 0.67. 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?

Footnote: Why Rely on HadSST4

HadSST is distinguished from other SST products because HadCRU (Hadley Climatic Research Unit) does not engage in SST interpolation, i.e. infilling estimated anomalies into grid cells lacking sufficient sampling in a given month. From reading the documentation and from queries to Met Office, this is their procedure.

HadSST4 imports data from gridcells containing ocean, excluding land cells. From past records, they have calculated daily and monthly average readings for each grid cell for the period 1961 to 1990. Those temperatures form the baseline from which anomalies are calculated.

In a given month, each gridcell with sufficient sampling is averaged for the month and then the baseline value for that cell and that month is subtracted, resulting in the monthly anomaly for that cell. All cells with monthly anomalies are averaged to produce global, hemispheric and tropical anomalies for the month, based on the cells in those locations. For example, Tropics averages include ocean grid cells lying between latitudes 20N and 20S.

Gridcells lacking sufficient sampling that month are left out of the averaging, and the uncertainty from such missing data is estimated. IMO that is more reasonable than inventing data to infill. And it seems that the Global Drifter Array displayed in the top image is providing more uniform coverage of the oceans than in the past.

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

USS Pearl Harbor deploys Global Drifter Buoys in Pacific Ocean

2025 Update: No, CO2 Doesn’t Drive the Polar Vortex

Posted on July 2 by Ron Clutz

July 2025 Update

Linnea Lueken published this week at Climate Realism Thanks, NewScientist, for Admitting Climate Change Isn’t Making the Jet Stream More Erratic. Excerpts in italics with my bolds and added images.

NewScientist, a publication dedicated to popularizing science, recently published a post titled “Extreme winter weather isn’t down to a wavier jet stream,” reporting on a new study that shows, the jet stream is not getting wavier in winter months due to climate change. NewScientist writes that “[i]ncreasingly erratic winter weather in the northern hemisphere isn’t a result of the polar jet stream getting more wavy, according to new research . . ..”

This is true, and it has been evident for some time, but runs counter
to assertions commonly made by climate alarmists.

Although the vast bulk of the article is devoted to insisting that climate change is causing worsening winter and summer weather, claims regularly debunked at Climate Realism, the publication deserves some credit for reporting the study’s results concerning the jet stream, which was, in fact, the focus of the research itself.

The new reports findings are not actually that “new,” in the sense that Climate Realism has reported on research that came to the same conclusion several times in the past few years, here, here, and here, for instance. There is copious evidence showing that not only are cold snaps not uncommon, but that the jet stream’s (and more specifically, polar vortex) influence on extreme winter weather has been acknowledged since at least 1853. Years of studies looking at the frequency of and intensity of polar vortex events have found no consistent trends. As pointed out by my colleague Anthony Watts in this post on the subject:

“a 2021 study in the journal Geophysical Research Letters found no statistically significant increase in jet stream waviness or meandering in recent decades,”

and he explains there has never been a consensus among scientists when it comes to the issue of polar vortex/jet stream behavior.

The post at NewScientist goes on to explain the new study, saying “recent erratic behaviour isn’t out of the ordinary,” and that the jet stream has been both wavier and less wavy than it is today. Unfortunately, that is where the NewScientist and the authors of the paper it was discussing ceased to follow the evidence. One of the study’s authors reassured NewScientist that climate change is still “affecting extreme weather events in all sorts of really important ways,” and that the jet stream is actually becoming wavier in the summertime, “where it is getting slower, with bigger waves, which leads to things like big heatwaves, drought, and wildfires.”

This would be compelling if existing data backed up the claim,
but, in fact, big heatwaves, drought, and wildfires have not
become more frequent or severe in recent decades.

Heatwaves were much more severe in the earlier decades of the 20^th century, and overall drought has been declining while precipitation increases. Now that it is summer, many outlets are attempting to claim that hot weather is driven by climate change. In doing so they almost always ignore where heat records are being set, as it is often at airports and other heat-absorbing locations, and ignore historical records that show hot summers are not unprecedented.

Similarly, data shows that wildfires were worse in the past with research from NASA and the European Space Agency showing that acreage lost to wildfires has declined markedly over the past few decades.

The NewScientist, and the AGU study it references, should have quit when they were ahead. They should have published their unalarming findings about climate change’s lack of an impact on the winter jet stream without then assuring people that despite their study’s findings, they really are true believers and climate change is making weather worse. The latter point is refuted by real world data.

Simulation of jet stream pattern July 22. (VentuSky.com)

Background from Previous Post

We are heading into winter this year at the bottom of a solar cycle, and ocean oscillations due for cooling phases. The folks at Climate Alarm Central (CAC) are well aware of this, and are working hard so people won’t realize that global cooling contradicts global warming. No indeed, contortionist papers and headlines are warning us all that CO2 not only causes hothouse earth, overrun with rats and other vermin. CO2 also causes ice ages when it feels like it.

Update Nov. 26, 2019: Much ado about the polar jet stream recently with a publication by Tim Woolings A battle for the jet stream is raging above our heads. The Claims are not new:

The jet has always varied – and has always affected our weather patterns. But now climate change is affecting our weather too. As I explore in my latest book, it’s when the wanderings of the jet and the hand of climate change add up that we get record-breaking heatwaves, floods and droughts – but not freezes.

The same supposition was made last year in an article by alarmist Jason Samenow at Washington Post. Study: Freak summer weather and wild jet-stream patterns are on the rise because of global warming. Excerpts in italics with my bolds

In many ways, the summer of 2018 marked a turning point, when the effects of climate change — perhaps previously on the periphery of public consciousness — suddenly took center stage. Record high temperatures spread all over the Northern Hemisphere. Wildfires raged out of control. And devastating floods were frequent.

Michael Mann, climate scientist at Pennsylvania State University, along with colleagues, has published a new study that connects these disruptive weather extremes with a fundamental change in how the jet stream is behaving during the summer. Linked to the warming climate, the study suggests this change in the atmosphere’s steering current is making these extremes occur more frequently, with greater intensity, and for longer periods of time.

The study projects this erratic jet-stream behavior will increase in the future, leading to more severe heat waves, droughts, fires and floods.

The jet stream is changing not only because the planet is warming up but also because the Arctic is warming faster than the mid-latitudes, the study says. The jet stream is driven by temperature contrasts, and these contrasts are shrinking. The result is a slower jet stream with more wavy peaks and troughs that Mann and his study co-authors ascribe to a process known as “quasi-resonant amplification.”

The altered jet-stream behavior is important because when it takes deep excursions to the south in the summer, it sets up a collision between cool air from the north and the summer’s torrid heat, often spurring excessive rain. But when the jet stream retreats to the north, bulging heat domes form underneath it, leading to record heat and dry spells.

The study, published Wednesday in Science Advances, finds that these quasi-resonant amplification events — in which the jet stream exhibits this extreme behavior during the summer — are predicted to increase by 50 percent this century if emissions of carbon dioxide and other greenhouse gases continue unchecked.

Whereas previous work conducted by Mann and others had identified a signal for an increase in these events, this study for the first time examined how they may change in the future using climate model simulations.

“Looking at a large number of different computer models, we found interesting differences,” said Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research and a co-author of the study, in a news release. “Distinct climate models provide quite diverging forecasts for future climate resonance events. However, on average they show a clear increase in such events.”

Although model projections suggest these extreme jet-stream patterns will increase as the climate warms, the study concluded that their increase can be slowed if greenhouse gas emissions are reduced along with particulate pollution in developing countries. “[T]he future is still very much in our hands when it comes to dangerous and damaging summer weather extremes,” Mann said. “It’s simply a matter of our willpower to transition quickly from fossil fuels to renewable energy.”

Mann has been leading the charge to blame anticipated cooling on fossil fuels, his previous attempt claiming CO2 is causing a slowdown of AMOC (part of it being the Gulf Stream), resulting in global cooling, even an ice age. The same idea underlay the scary 2004 movie Day After Tomorrow.

day-after-tomorrow Other scientists are more interested in the truth than in hype. An example is this AGU publication by D.A Smeed et al. The North Atlantic Ocean Is in a State of Reduced Overturning Excerpts in italics with my bolds.

Figure 3

Indices of subsurface temperature, sea surface height (SSH), latent heat flux (LHF), and sea surface temperature (SST). SST (purple) is plotted using the same scale as subsurface temperature (blue) in the upper panel. The upper panel shows 24 month filtered values of de‐seasonalized anomalies along with the non‐Ekman part of the AMOC. In the lower panel, we show three‐year running means of the indices going back to 1985 (1993 for the SSH index).

Changes in ocean heat transport and SST are expected to modify the net air‐sea heat flux. The changes in the total air‐sea flux (Figure S4, data obtained from the National Centers for Environmental Prediction‐National Center for Atmospheric Research reanalysis; Kalnay et al., 1996) are almost all due to the change in LHF. The third panel of Figure 3 shows the changes in LHF between the two periods. There is a strong signal with increased heat loss from the ocean over the Gulf Stream. That the area of increased heat loss coincides with the location of warming SST indicates that the changes in air‐sea fluxes are driven by the ocean.

Whilst the AMOC has only been continuously measured since 2004, the indices of SSH, heat content, SST, and LHF can be calculated farther back in time (Figure 3, bottom). Over this longer time period, all four indices are strongly correlated with one another (Table S5; correlations were calculated using the nonparametric method described in McCarthy et al., 2015). These data suggest that measurement of the AMOC at 26°N started close to a maximum in the overturning. Prior to 2007 the indices show variability on a time scale of 8 to 10 years and no trend is evident, but since 2014 all indices have had values lower than any other year since 1985.

Previous studies have shown that seasonal and interannual changes in the subtropical AMOC are forced primarily by changing wind stress mediated by Rossby waves (Zhao & Johns, 2014a, 2014b). There is growing evidence (Delworth et al., 2016; Jackson et al., 2016) that the longer‐term changes of the AMOC over the last decade are also associated with thermohaline forcing and that the changed circulation alters the pattern of ocean‐atmosphere heat exchange (Gulev et al., 2013). The role of ocean circulation in decadal climate variability has been challenged in recent years with authors suggesting that external, atmospheric‐driven changes could produce the observed variability in Atlantic SSTs (Clement et al., 2015). However, the direct observation of a weakened AMOC supports a role for ocean circulation in decadal Atlantic climate variability.

Our results show that the previously reported decline of the AMOC (Smeed et al., 2014) has been arrested, but the length of the observational record of the AMOC is still short relative to the time scales of important decadal variations that exist in the Atlantic. Understanding is therefore constantly evolving. What we identify as a changed state of the AMOC in this study may well prove to be part of a decadal oscillation superposed on a multidecadal cycle. Overlaying these oscillations is the impact of anthropogenic change that is predicted to weaken the AMOC over the next century. The continuation of measurements from the RAPID 26°N array and similar observations elsewhere in the Atlantic (Lozier et al., 2017; Meinen et al., 2013) will enable us to unravel and reveal the role of ocean circulation in the changing Atlantic climate in the coming decades.

Regarding the more recent attempt to link CO2 with jet stream meanderings, we have this paper providing a more reasonable assessment. Arctic amplification: does it impact the polar jet stream? by Valentin P. Meleshko et al. Excerpts below in italics with my bolds.

Analysis of observation and model simulations has revealed that northward temperature gradient decreases and jet flow weakens in the polar troposphere due to global climate warming. These interdependent phenomena are regarded as robust features of the climate system. An increase of planetary wave oscillation that is attributed to Arctic amplification (Francis and Vavrus, 2012; Francis and Vavrus, 2015) has not been confirmed from analysis of observation (Barnes, 2013; Screen and Simmonds, 2013) or in our analysis of model simulations of projected climate. However, we found that GPH variability associated with planetary wave oscillation increases in the background of weakening of zonal flow during the sea-ice-free summer. Enhancement of northward heat transport in the troposphere was shown to be the main factor responsible for decrease of northward temperature gradient and weakening of the jet stream in autumn and winter. Arctic amplification provides only minor contribution to the evolution of zonal flow and planetary wave oscillation.

It has been shown that northward heat transport is the major factor in decreasing the northward temperature gradient in the polar atmosphere and increasing the planetary-scale wave oscillation in the troposphere of the mid-latitudes. Arctic amplification does not show any essential impact on planetary-scale oscillation in the mid and upper troposphere, although it does cause a decrease of northward heat transport in the lower troposphere. These results confound the interpretation of the short observational record that has suggested a causal link between recent Arctic melting and extreme weather in the mid-latitudes.

There are two additional explanations of factors causing the wavy jet stream, AKA Polar Vortex. Dr Judah Cohen of AER has written extensively on the link between Autumn Siberian snow cover and the Arctic oscillation. See Snowing and Freezing in the Arctic for a more complete description of the mechanism.

Finally, a discussion with Piers Corbyn regarding the solar flux effect upon the jet stream at Is This Cold the New Normal?

Video transcript available at linked post.

The Real Climate Science Crisis: CAGW Hypothesis Lacks Scientific Evidence

Posted on June 28 by Ron Clutz

From C3 headlines The Real Climate Science Crisis: The Catastrophic Anthropogenic Global Warming (CAGW) Hypothesis Is Without Scientific Evidence. Excerpts in italics with my added images.

For a hypothesis to reach the status of being a legit theory, it requires withstanding the onslaught of observed empirical evidence. The CAGW hypothesis is no such animal.

Known by its more contemporary aliases, such as ”climate crisis,” “climate emergency,” “climate collapse,” or “existential threat,” the CAGW has zero empirical evidence to support it.

Unlike the related hypothesis regarding greenhouse gases (GHG) and global warming, at least the GHG hypothesis has warming global temperature data that somewhat coincides with increasing atmospheric CO2 levels, putting aside the growing possibility that the purported cause-and-effect direction is probably the reverse.

In order to reach a CAGW climate disaster, global warming
temperatures must change rapidly in an accelerating manner
that will initiate a ‘tipping point’ for the climate.

The rapid acceleration would present its occurrence in a continuous increasing of the slope, i.e., trend, of temperatures, such as monthly temperatures. Each subsequent month would represent a greater temperature magnitude increase than the month before, hypothetically.

But those tipping point precursors are not occurring in the real-world climate.

For example, it is agreed by all climate scientists that oceans play a very major role in the world’s climate and its global temperatures due to their being both the world’s largest carbon sink and its largest heat content storage.

However, despite these characteristics, in totality, the global oceans HAVE NOT warmed since the year 2014. And certainly, there is no empirical evidence that oceans exhibit constant temperature increases of magnitude.

Quite the contrary, combined oceans exhibit a regular pattern of temperature decreases and increases, as the adjacent plot of NOAA’s monthly ocean data indicates.

Specifically, this is a plot (dark blue) of moving 5-year temperature changes ending each month of the 60-year period from March 1963 through March 2023.

[Explanation: the first data point is the temperature change for the 60 months ending on March 30, 1963; and the chart’s last temperature change data point is for the five 5 years (i.e. 60 months) ending on March 2023.]

The chart also includes a plot (green) of the moving 60-month CO2 level changes over the same sixty year period, plus a linear trend for both CO2 changes and ocean temperature changes.

The trend of the 60-month CO2 changes significantly exceeds the slight positive trend of ocean temperature changes by a factor of 117x. This huge differential undercuts the belief that global warming is primarily the result of GHGs. Which is confirmed by the paltry R^2 of +0.06 – an almost non-existent relationship between 5-year atmospheric CO2 changes and 5-year changes in ocean temperature.

Not only are the large increases in CO2 levels not causing a concerning uptick of temperature change magnitude, it also has not lead to any type of acceleration, per the linear trend since 1963.

Specifically, with a trend of a tiny +0.0001°C, that would project out 20 years to be an increase of 5-year temperature changes to an insignificant amount of +0.024°C – definitely not an existential threat of ‘runaway warming’ or a CAGW ‘climate crisis’ as portrayed by bureaucrats, politicians and Hollywood celebrities.

So, if 5 years of increasing amounts of CO2 in the atmosphere barely influence 5-year changes in temperature over a 60-year span, either in magnitude or acceleration rate, then it is highly unlikely that this trace gas would cause a catastrophic climate disaster or an extinction event.

Thus, it is fair to state that for all those scientists pushing a narrative of an imminent climate change catastrophe from CO2 without the requisite empirical evidence, this has become the real climate science crisis facing society.

It’s Summertime, Hottest Year Claims Ensue

Posted on June 21 by Ron Clutz

Matthew Wielicki explains the scientific malpractice in his Financial Post article Junk Science Week: The hottest year ever?. Excerpts in italics wtih my bolds and added images

Advocates and the media claim 2024 was the hottest year ever.
Archeological data suggest it wasn’t,
while modern data suffer from biases

An image produced by NASA and used when it declared 2024 as the warmest year on record. Photo by NASA

In 2024, mainstream media and political leaders aggressively promoted the alarming narrative that Earth had just experienced its hottest year ever recorded. National Geographic dramatically proclaimed, “2024 was the hottest year ever … and the coldest year of the rest of your life,” while the Vancouver Sun declared unequivocally, “Scientists confirm 2024 was Canada’s and world’s hottest year on record.” Canadian political figures reinforced this narrative, with prime minister Justin Trudeau characterizing the year’s warmth as an urgent call for immediate climate action.

I’m an earth science professor-in-exile. Claims such as these
immediately provoke critical skepticism.

This persistent narrative, relentlessly advanced by a powerful climate-industrial complex comprising governments, activist organizations and the media, is designed not merely to inform, but to generate a state of perpetual urgency. As global greenhouse gas (GHG) emissions continue to rise despite decades of climate policy interventions, the need to claim climate conditions are increasingly severe becomes a strategic imperative, regardless of scientific accuracy or historical context. This approach not only distorts genuine scientific inquiry but fosters anxiety and despair, particularly affecting young people already inundated with predictions of catastrophe.

The answers to four fundamental questions expose the weaknesses and biases inherent in the mainstream climate narrative:

1. Can we accurately measure historical global temperatures?

Claims about unprecedented global heat depend heavily on comparing modern temperature records, which are gathered by instrument and capture annual or monthly fluctuations, to historical temperature estimates derived from proxy data such as ice cores, tree rings, sediment layers and coral reefs. But proxy data inherently smooths out short-term fluctuations, providing generalized temperature estimates spanning centuries or millennia. This mismatch between high-resolution modern data and low-resolution historical proxies inevitably exaggerates the perceived severity of contemporary warming.

For example, widely cited reconstructions and favourites of The Intergovernmental Panel on Climate Change (IPCC) explicitly acknowledge their inability to capture temperature variability occurring over periods shorter than 300 years. The rapid temperature changes of recent decades appear unprecedented when put side by side with these smoothed historical averages. This methodological flaw significantly undermines the credibility of claims asserting that current global temperatures are historically unique or alarming.

2. Was 2024 really unprecedentedly warm?

Extensive historical and geological evidence demonstrates significant natural warming vastly exceeding modern temperatures. The Holocene Thermal Maximum (five to nine thousand years ago) saw temperatures significantly warmer than today, including in Canada. Archeological evidence, such as ancient forests revealed by retreating glaciers in the Rockies, conclusively supports periods of substantial natural warmth.

During the Eemian interglacial period (115-130 thousand years ago), Greenland experienced temperatures three to five degrees C warmer than now, despite substantially lower CO₂ concentrations in the atmosphere. These scientifically documented periods confirm that Earth’s climate naturally experiences considerable variability, rendering claims of unprecedented modern warmth scientifically untenable and historically uninformed.

3. Are we measuring the effects of CO₂ or urban heat islands

Most modern temperature records fuelling alarmist headlines originate from urban areas influenced by the Urban Heat Island Effect (UHIE). UHIE results from urban infrastructure, such as concrete, asphalt and buildings, retaining and radiating heat, significantly increasing local temperatures independent of broader climate trends. Toronto’s significant infrastructure growth has noticeably raised local temperatures, heavily skewing data. Similarly, Las Vegas’ highest recorded temperatures coincided with significant expansion around Harry Reid International Airport, illustrating the dominant role of urbanization rather than atmospheric CO₂ emissions.

Recent research indicates that up to 65 per cent of urban warming is from local urbanization rather than global greenhouse gas increases. Attributing urban heat predominantly to CO₂ emissions significantly misrepresents the true dynamics of local temperature increases.

4. Do rising CO2 levels really heat the oceans?

Recent alarmist coverage in outlets like the Financial Times highlights near-record ocean temperatures, linking them directly to rising CO₂ levels. The EU’s Copernicus programme noted that May 2025 ocean temperatures were the second highest ever recorded, with scientists raising concerns about the oceans’ diminishing capacity to absorb CO₂ and excess heat.

But this narrative critically overlooks fundamental scientific facts. Oceans possess a heat capacity orders of magnitude greater than the atmosphere. The notion that atmospheric CO₂ significantly heats ocean water directly is scientifically unfounded, as infrared radiation from CO₂ penetrates mere millimetres into the ocean’s surface, not nearly deep enough to meaningfully alter ocean temperature. Ocean temperature fluctuations are primarily driven by natural phenomena such as El Niño.

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.

Moreover, historical data on ocean temperatures is highly uncertain, relying predominantly on sparse measurements and indirect proxies. Claiming near-record ocean temperatures without acknowledging these substantial uncertainties misleads the public about the robustness and reliability of these measurements.

Critical conclusion: One thing remains certain: it will never be “too hot” in Canada, despite alarmist rhetoric suggesting otherwise. The exaggerated claims that 2024 was “the hottest year ever” are not grounded in rigorous scientific analysis but serve primarily as political and ideological propaganda. This relentless propagation of fear fosters anxiety, despair, and nihilism, especially among young people — serious consequences largely ignored by climate alarmists.

The scientific community, policy-makers and the public at large need to insist on transparency, rigour and honesty in climate discourse. Recognizing the motivations behind alarmist claims is essential to ensuring public trust and effective policy. Climate science should strive to educate, not frighten, promoting balanced understanding rather than catastrophic narratives disconnected from historical context and scientific rigour.

Matthew Wielicki, Ph.D. in geochemistry from UCLA, publishes the Substack site Irrational Fear, which provides data-driven critiques aimed at fostering a balanced and scientifically grounded understanding of climate science.

May 2025 Two Years of Ocean Cooling Persists

Posted on June 19 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.

The Current Context

The chart below shows SST monthly anomalies as reported in HadSST4 starting in 2015 through May 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.

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 last year, ~0.3° higher than the 2015 peak. Then NH started down autumn 2023, followed by Tropics and SH descending 2024 to the present. After 12 months of cooling in SH and the Tropics, the Global anomaly came back down, led by NH cooling the last 8 months from its 1.3C peak in August, down to 0.8C in March and April. Remarkably, April 2025 SST anomalies in all regions and globally are the coolest since March 2023. May shows little change in the Global anomaly, with a SH decline offsetting an upward bump in NH.

Comment:

A longer view of SSTs

To enlarge image, open in new tab.

Contemporary AMO Observations

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

The purple line is the average anomaly 1980-1996 inclusive, value 0.17. The orange line the average 1980-2024, value 0.38, also for the period 1997-2012. The red line is 2013-2024, value 0.67. 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

Footnote: Why Rely on HadSST4

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

USS Pearl Harbor deploys Global Drifter Buoys in Pacific Ocean

Climatists’ Childish Reading of Polar Ice

Posted on June 17 by Ron Clutz

Vijay Jayaraj explains in his Cornwall Alliance article Climate-obsessives’ Infantile Reading of Polar Ice. Excerpts in italics with my bolds and added images.

Whenever “experts are shocked” they usually have marginalized or ignored altogether factors wrongly assumed to have no influence over their hypotheses, theories or beliefs.

Nowhere is this more evident than in climate science where changes in geophysical phenomenon continue to defy assumptions and forecasts presented by some of the most highly paid and influential scientists on the planet.

Among the most infamous examples is the failure of computer climate models to accurately predict real-world temperatures. This is predominantly due to the unscientific exaggeration of carbon dioxide’s (CO₂’s) potency in warming the atmosphere.

Charts showing annual gains and losses of Surface Mass Balance (SMB) of Greenland Ice Sheet GIS. Note accumulations above the mean in these years. Note also that each year starts from zero, not showing additions from the previous year.

Now scientists have encountered more “shocks” as polar sea ice is refusing to behave as expected. Since September 1, 2024, an astonishing 579 billion tons of fresh snow and ice have blanketed the Greenland ice sheet, marking the most significant accumulation for that date in at least eight years—far surpassing the 1981-2010 average.

Meanwhile, both the North and South Poles are defying expectations, piling on more ice despite, as reported in hyperbolic headlines, “record-breaking” global heat. It’s a breathtaking, almost surreal twist in the story of our planet’s climate!

According to NASA, “Arctic sea ice reaches its minimum extent (the area in which satellite sensors show individual pixels to be at least 15% covered in ice) each September.”

In the post-2010 era, the September minimum extent of Arctic sea ice occurred in 2012, which was also the lowest since satellite measurements began in 1980. But ever since 2012, ice has been increasing or oscillating well above that year’s mark.

Likewise, the volume of sea ice has not significantly dropped since 2012 and there has been a nominal increase in volume since a low point of 2020.

So, why is the minimum coverage of Arctic sea ice holding above the level of 2012?

One of the most obvious reasons could be that CO₂ is not as powerful a temperature control knob as claimed, which is a possibility that many well-funded scientists refuse to even take into consideration.

Also, remember that we are in the Holocene epoch, a warm geological phase between two glacial advances – one that ended about 10,000 years ago and the next expected to occur some number of thousand years hence. An upward tick in Arctic temperatures shouldn’t surprise us regardless of whether we emit CO₂ or not. In fact, Arctic ice levels witnessed in the 17^th century during the Little Ice Age were among the highest since continental glaciers blanketed Canada and extended into the lower 48 states to create the Great Lakes.

At one point, news media were abuzz with the unexpected gain in Antarctica’s ice mass. Antarctica gained ice from 2021 to 2023, with studies showing nearly 108 gigatons per year added, mainly due to increased snowfall in East Antarctica.

Data from Vostok and Concordia stations in East Antarctica indicate extremely cold temperatures in early May, with minimums of minus 106.6 degrees Fahrenheit at Concordia on May 12. With winter just beginning, the temperatures are likely to dive further.

As recently as 2023, Concordia station recorded one of its lowest temperatures for the current decade, a brutal minus 117.76 degrees. Similarly, at Western Antarctica’s Byrd Station, a likely all-time low of almost minus 50 degrees was recorded as recently as 2023. These numbers may be surprising, but they are in tune with the unpredictability of climate – and of nature in general. Let’s just admit it. Things are not as “straightforward” as crisis-obsessed scientists are making them out to be. The climate system is complex, and the science is not settled. Our understanding of climatic dynamics is in its infancy. And to suggest that changes –whatever the direction – in polar ice presage a catastrophe is infantile.

Meet Téa Johansson, Teenage Climate Realist

Posted on June 15 by Ron Clutz

For those who prefer reading, below is a transcript lightly edited from the closed captions with my bolds along with some of the exhibits and added images.

Life on Earth is in crisis crop failure, social and ecological collapse, mass extinction. We have a moral duty to take action. These statements made by Extinction Rebellion reflect the climate alarmist narrative that has continued to escalate across the Western world. Hysteria over climate change can be seen throughout history, from the human sacrifices of the Aztecs to bring back rain, to the Salem witch trials to eliminate the women they blamed for crop failure during the little ice age.

Today the climate industrial complex is funded by trillions of dollars seeking to control what we buy, eat and where we are allowed to travel, all in the name of sustainability and achieving net zero carbon emissions. This fear campaign is rooted in the belief that we will not look into the data ourselves, but instead look to the governments and to the media to tell us what is true.

Today I will demonstrate that temperatures fluctuate and are not unprecedented, and that natural disasters are not getting worse. I will also highlight the unreliability of climate data and the role of CO2. Ultimately I will present scientific evidence to show that we are not in a climate crisis.

Historical temperature records indicate that we are not in the climate crisis western governments claim. We are looking at a graph of the past 65 million years from NOAA. The Earth today seems to be in a particularly cool period; in fact the Earth is still coming out of an ice age. History demonstrates that life has existed and thrived in much warmer temperatures, and that temperatures have been much higher without the human influence of industrial CO2 emissions.

Historical temperature records indicate that the temperature of the Earth naturally fluctuates over time as it has for the past 65 million years. In just the past 2,000 years there have been two warm periods and two cold periods. The Roman warm period, also called the Roman optimum, was known as a time of prosperity. This of course goes against the entire narrative that warming threatens human life. Following the Roman warm period came the cold dark age, the medieval warm period, and the Little Ice Age. The current warming from 1800 onwards is the warming of recovery from the Little Ice Age. However temperatures are still cold compared to distant times and continue to visibly fluctuate.

Given this evidence, the claim by scientists and news pundits that 3° Fahrenheit is the end of civilization is not cause for alarm. Because it is not unprecedented and because temperatures will continue to fluctuate today. The argument for climate change is rooted in the belief that warmer weather and CO2 emissions have been causing natural disasters to become more frequent and more violent. However after studying hurricane and wildfire data, it became clear that actual activity goes against this global warming narrative.

This graph from the bulletin of the American Meteorological Society shows the number of hurricanes in the US per year since 1900 showing a slight downward trend for the past 120 years. The strength and duration of hurricanes shows a similar lack of crisis.

A graph from the National Hurricane Research Laboratory illustrates the North Atlantic hurricane intensity from 1920 to 2016, where there is evidently no trend. However the data presented to the public by the 2014 National Climate Assessment of the United States is limited to the portion highlighted in red creating an illusory upward trend.

This graph starting in 1920 shows that the number of acres burned by wildfires in the US has been decreasing. Similarly the number of acres burned globally since 1900 has steadily declined as well. Ultimately the presented evidence goes against the narrative that anthropogenic CO2 emissions have been making the weather worse.

To understand the science behind the climate crisis claims of today, it is necessary to highlight the unreliability of available data. This is most evident in the disparity between climate model predictions and the observed data. In this graph illustrating temperature change, the blue line representing data taken from weather balloons matches up well with the green line showing data taken from satellites. However the red line represents the climate models used by the UNIPCC to predict future global warming. These observations show that actual warming is about one third of that predicted.

Temperature measurements are greatly affected by what is called the urban heat island effect. Since concrete picks up heat, temperatures taken in cities are much higher than those taken in rural areas. For example in a thermal radiation map of the city of Paris, the middle of the city produces a deep red color representing heat, while the rural areas around the city project a green to bluecolor representing milder temperatures.

This gap represents one way that climate alarmists can instill fear by embellishing data to serve their agenda. Perhaps the greatest tool of the climate industrial complex is the supposed evil of CO2. However CO2 is not the control knob for climate change mainly because it is only 0.04% of the atmosphere. I’ll say it again: CO2 is only 0.04% of the atmosphere. A visual comparison of CO2 to the other atmospheric gases shows how barely negligible is the gas in comparison.

Although the mainstream media has tried to alarm its consumers with the accelerating emissions of CO2, the Earth is actually in a CO2 famine. Current levels are about 423 parts per million; however in the past they have been at least a thousand parts per million and have likely reached 8,000 parts per million.

While the narrative states that CO2 directly causes the rise in temperature, it has been found that quite the opposite is true. The relationship between CO2 and temperature is not that more CO2 causes a rise in temperature, but that a rise in temperature causes an increase in CO2. Carl Wunsch, professor of oceanography at MIT, found that when the ocean warms more CO2 is released into the atmosphere. On the other hand when the ocean is cold, CO2 is absorbed into the water.

In a graphical correlation between temperature and CO2, it is found that when a rise in temperature occurs, a rise in CO2 follows a few centuries later. In this graph CO2 rose 800 years later in response to a surge in temperature.

Like everything else in the world, CO2 may have some small factor in climate, while there are countless of other factors affecting temperature. Some examples are volcanic activity, cosmic rays, and the sun. This highlights how if we were to limit CO2, it would only stunt biodiversity while having almost no effect on temperature. Because of the fact that it is only one small factor in a sea of greater causes.

Some call CO2 the gas of life because it plays an instrumental role in the process of photosynthesis. It comes as no surprise that most farmers use high levels of it in their green houses to produce a better crop. In this picture four pine trees are shown growing at different levels of added CO2, from normal atmospheric CO2 to an added 150, 300, and eventually 450 parts per million. More CO2 is evidently beneficial for plant growth. Physicist Lubos Motl, former professor at Harvard, summarized the importance of CO2, saying “It is the key compound that plants need to grow, and indirectly every organism needs to have food. At the end it is clear that CO2 is not, as the New York Times frighteningly put it, a tiny bit of arsenic or cobra venom. Nor will it cause famine as many claim; if CO2 increases it will only green the planet and increase the food supply.

Across the western world climate change has been coined as an existential threat to mankind. While this sentiment is not new over the course of history, as it can be seen through the Aztecs and even in the Salem witch trials. It has once again become relevant in today’s culture with policies such as carbon taxes and individual CO2 budgets being proposed in our governments. We are seeing the climate issue creep into every part of our lives.

This is why I I found it necessary to pursue the truth and the climate debate. In my speech I presented the scientific evidence behind historical temperature change and natural disasters, discovering the unreliability of climate data, the small role of CO2 in climate, and its essential role in biodiversity. As a result I’ve concluded that the climate crisis is a hoax that we must arm ourselves against by pursuing the truth and by looking into the data ourselves.

NH and Tropics Lead UAH Temps Lower May 2025

Posted on June 12 by Ron Clutz

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 ~60 ppm, a 15% 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

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

May 2025 NH and Tropics Lead UAH Temps Lower

UAH has updated their TLT (temperatures in lower troposphere) dataset for May 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 of the update from HadSST4. I posted recently on SSTs April 2025 Two Years Ocean Warming Gone. 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. Then land air temps, especially NH, dropped in February and recovered in March. Now in May both land and sea temps are down in NH and Tropics, overwhelming slight rises of both in SH.

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 May 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.

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. Now 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 are similar to May 2020, albeit with higher SH anomalies.

Land Air Temperatures Tracking in Seesaw Pattern

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. In March that drop reversed with both NH and Global land back to January values, holding there in April. Now in May, sharp drops in NH and Tropics land air temps pulled the Global land air temps back down close to February value.

The Bigger Picture UAH Global Since 1980

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

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