Author: Iowa Climate Science Education

No More Easy Ride for Wind and Solar

New wind and solar projects are expected to decline sharply over the next two years as the One Big Beautiful Bill’s strict tax credit rules, supply chain restrictions, and aggressive enforcement drive up costs and risk. With subsidies set to expire after 2027 for new projects, the decades-long era of easy tax-driven renewable development is coming to an end.

“Under the new law, eligibility for the Production Tax Credit (PTC) and Investment Tax Credit (ITC) has become far more complex and legally uncertain. That’s by design. The One Big Beautiful Bill Act prioritizes strengthening America’s energy system with reliable, dispatchable power—not tax-driven projects that weaken the grid’s resilience.”

The One Big Beautiful Bill Act (OBBB) marks a major shift in U.S. energy policy—one that places American taxpayers and national interests squarely at the center of federal energy incentives. For too long, generous tax credits for wind, solar, and battery projects disproportionately benefited developers and tax equity investors, often with little scrutiny over whether those projects served meaningful economic or national objectives.

Under the new law, eligibility for the Production Tax Credit (PTC) and Investment Tax Credit (ITC) has become far more complex and legally uncertain. That’s by design. The OBBB prioritizes strengthening America’s energy system with reliable, dispatchable power—not tax-driven projects that weaken the grid’s resilience.

For tax equity investors—whose participation depends on predictable tax credit monetization—this new environment is especially risky. Without assurance that a project will ultimately qualify, many may refuse to invest. Legal opinions that once provided comfort may now come with significant qualifications, leaving developers and investors navigating far more uncertain terrain.

At the heart of this shift are three critical risks: stricter scrutiny of what qualifies as “beginning construction,” tough new supply chain rules aimed at eliminating dependence on Foreign Entities of Concern (FEOCs), and an aggressive enforcement mandate delivered by executive order.

The sections below explain how these reforms work together to protect taxpayers, reduce federal exposure to questionable projects, and ensure that any future renewable development serves America’s long-term economic and national security priorities—not just the financial interests of developers and investors.

Preventing Construction Timeline Gaming

One of the most immediate risks centers on how—and when—a renewable energy project is deemed to have “begun construction.” The OBBB codifies the IRS’s longstanding tests—the Physical Work Test and the 5 percent Safe Harbor—as they existed on January 1, 2025. But codification should not be mistaken for certainty. Key terms like “physical work of a significant nature” remain undefined in both statute and guidance, giving Treasury ongoing discretion to interpret or narrow their application.

Timing is critical. Projects that begin construction between July 4, 2025, and July 4, 2026, have a four-year window to complete construction and be placed in service while still qualifying for credits. Any project that starts on or after July 5, 2026, faces a hard deadline—completion by the end of 2027—or it forfeits eligibility for the PTC and ITC. This compressed timeline is likely to sharply reduce new project starts after July 4, 2026. (See Table)

This looming deadline creates predictable pressure on developers to lock-in their construction start dates during the 12-month window following enactment. However, developers and investors must understand the limits of the safe harbor protections. The four-year safe harbor only applies to the continuity requirement—that is, assuming construction genuinely began, the IRS will not second-guess whether the project progressed continuously if it meets the deadline.

But the IRS still retains full authority to examine whether construction genuinely “began” in the first place. If the facts suggest that a developer’s claimed start of construction was superficial, premature, or staged merely to preserve tax credit eligibility, the IRS may disallow credits retroactively—regardless of whether the four-year window was met.

Developers and tax equity investors must be prepared to substantiate not only that they met the timeline but that they genuinely satisfied the start-of-construction standard with credible, documented evidence of real construction activity. Anything less leaves the project—and the tax credits—exposed to challenge.

Reckoning for Foreign Supply Chains

The second major compliance challenge comes from the OBBB’s new restrictions on the use of materials and components sourced from Foreign Entities of Concern. For years, renewable developers relied on opaque global supply chains—especially in China—for solar panels, wind turbine parts, and battery components. These foreign sources often have ties to forced labor, military-linked entities, or regimes hostile to U.S. interests.

Wind and solar projects that start construction in 2026 and expect PTC or ITC support must meet a strict Material Assistance Cost Ratio (MACR) threshold: at least 40% of direct material costs must come from non-prohibited sources. For projects starting construction in 2027 the ratio increases to 45%.[1] Failing to meet the threshold disqualifies the project from federal tax credits.

This compliance burden will drive many developers to accelerate their construction start dates into 2025, before the FEOC restrictions kick in. The OBBB’s statutory anti-circumvention language grants Treasury sweeping authority to conduct audits and deny credits subject to lookback periods up to six years even if construction tests appear satisfied—based on “facts and circumstances.” Activities that once sufficed, such as stockpiling equipment or off-site prep work, may no longer be viewed as legitimate. Developers who start construction in 2026 must secure sworn certification from every supplier—under penalty of perjury—that no component or subcomponent was produced by, on behalf of, or controlled by a prohibited foreign entity.

Date Policy/Restriction Triggered Impact
Before 2025;
January 1 2025 -July 3, 2025
Prior to OBBB Enactment Not impacted by OBBB

July 4, 2025 OBBB Enactment Date Developers will likely rush to “begin construction” to qualify under existing tax credit rules before new restrictions hit.
July 4, 2025 – July 4, 2026 12-Month “Begin Construction” Window Projects started in this window get a 4-year completion window and avoid post-2026 restrictions, but risk heightened scrutiny over whether construction genuinely began.
January 1, 2026 FEOC Restrictions Begin Projects must begin complying with Foreign Entity of Concern (FEOC) sourcing rules — starting with a 40% U.S. or allied-sourced material threshold for wind/solar projects.
July 5, 2026 Post-Window Construction Restriction Projects started on or after this date must be placed in service by the end of 2027 — eliminating long construction timelines and likely curtailing new starts.
Six-Year Clawback Window IRS Enforcement Period The IRS can audit and claw back tax credits up to 6 years on FEOC sourcing violations, heightening long-term compliance risks.

Executive Order: A Broader Mandate for Strict Enforcement

On July 7, 2025, President Trump issued an Executive Order (E.O.) amplifying the OBBB’s enforcement agenda. The E.O. directs the Treasury Department to take “all action as the Secretary deems necessary” to prevent manipulation of both the FEOC compliance requirements and the construction start tests—even in cases where the statute itself is silent.

The E.O. reinforces the OBBB’s core objectives but does not expand Treasury’s legal authority beyond what the statute provides. Instead, the EO signals the administration’s clear intent to enforce the law aggressively, particularly regarding “begin construction” compliance and foreign supply chain restrictions. While the EO cannot create new penalties or rewrite statutory definitions, its real impact lies in shaping agency behavior—prioritizing strict audits, tougher guidance, and heightened regulatory oversight. In this sense, the E.O. magnifies the compliance risk developers and investors face under the OBBB, even though it does not alter the legal framework itself.

The E.O.’s mandate ensures that even technically compliant projects may face rigorous scrutiny—and potential retroactive challenge—if the government questions the substance of their construction start or supplier certifications.

Conclusion: The Reckoning Has Arrived

The OBBB and its companion Executive Order create a regulatory environment defined by aggressive oversight, stricter compliance demands, and real financial consequences. The dual burden of proving construction compliance and navigating complex foreign supply chain restrictions—often years after tax credits are claimed—will transform clean energy finance into a riskier, more disciplined endeavor.

For investors, the stakes are higher than ever. Without solid legal opinions, verifiable supplier chains, and consistent enforcement policies, many may choose to exit the market. For those who stay, the cost of risk will rise—along with the overall cost of renewable energy deployment.

And that’s exactly the point. For years, critics warned that renewable subsidies enriched private developers while delivering uncertain public value. The OBBB responds to those concerns by closing loopholes, demanding verifiable construction, and limiting reliance on hostile foreign suppliers. We can expect the result to be fewer speculative projects, more disciplined accounting, and a market correction long overdue. For Americans seeking reliable, affordable, and sovereign energy—this is the reckoning they’ve been waiting for.

— — — — — —

Lisa Linowes is an energy policy analyst and executive director of WindAction Group, where she monitors utility-scale renewable energy development and the public policies that shape its deployment.


[1] For energy storage projects, the MACR threshold begins at 55% in 2026 and rises by 5 percentage points annually, reaching 75% for projects beginning after 2029.

The post No More Easy Ride for Wind and Solar appeared first on Master Resource.

via Master Resource

https://ift.tt/lT1ELjR

July 22, 2025 at 01:04AM

The ‘Fruitful’ Results of Increasing CO2

By Vijay Jayaraj

Among the climatically correct, nothing is more scandalous than describing carbon dioxide (CO2) emissions as beneficial. You can be blacklisted from public forums, professional networking sites, and even be removed from your tenured university position as an accomplished scientist.

Nonetheless, the truth is this: CO2 is fundamental to the photosynthetic process by which plants make food for themselves – and ultimately for us. Furthermore, the increase in atmospheric CO2 from industrial activity in the past century has helped vegetation over most of the planet to flourish. Also benefiting plants has been the relative warmth of recent decades.

Among the beneficiaries are fruit plants, whose sensitivity to cold is well established. In April 2007, an unseasonable freeze caused considerable low-temperature injury to small fruit plants, including grapes, strawberries, blueberries and blackberries, in 21 U.S. states. The financial repercussions for the agricultural sector were substantial. In North Carolina alone, farming losses were estimated to be $112 million, including $86 million in damages to fruit crops.

During the Little Ice Age (1300–1850), many of the fruit crops faced significant challenges from low temperatures, shorter growing seasons and extreme weather events like frosts, heavy rains and drought.

In Iceland and high alpine areas, agriculture nearly collapsed. In China’s Jiangxi Province, centuries-old orange cultivation was abandoned due to cold. In temperate zones, apple and pear trees struggled with erratic temperatures causing irregular blooming and lower yields.

Fast forward 175 years or so, and we have fruit crops thriving globally, thanks to elevated CO2 levels, relative warmth and a series of innovations in plant biotechnology. Regardless of whether certain politicians or news media believe it or not, plants love the warmer temperatures and increasing carbon dioxide of our season of plenty.

Rising temperatures extend growing seasons by delaying fall frosts and advancing spring thaws, allowing more plantings and reducing late-spring frost risks for orchard growers. The U.S. growing season has lengthened by over two weeks since the early 20th century.

This commentary was first published by AmericanGreatness on July 21, 2025.

Vijay Jayaraj is a Science and Research Associate at the CO₂ Coalition, Fairfax, Virginia. He holds an M.S. in environmental sciences from the University of East Anglia and a postgraduate degree in energy management from Robert Gordon University, both in the U.K., and a bachelor’s in engineering from Anna University, India.


Discover more from Watts Up With That?

Subscribe to get the latest posts sent to your email.

via Watts Up With That?

https://ift.tt/RmGqrpt

July 22, 2025 at 12:04AM

Claim: Climate Crisis Food Price Inflation Delivered Victory to President Trump

Essay by Eric Worrall

Nothing to do with Biden and Kamala…

Rising food prices driven by climate crisis threaten world’s poorest, report finds

High cost of staples due to extreme weather could lead to more malnutrition, political upheaval and social unrest

Sarah Butler
Mon 21 Jul 2025 09.01 AEST

New research links last year’s surges in the price of potatoes in the UK, cabbages in South Korea, onions in India, and cocoa in Ghana to weather extremes that “exceeded all historical precedent prior to 2020”.

It found food price spikes can have a wider economic impact, making it harder for economies to keep down overall inflation and so, for example, bring interest rates down. A hot dry spring in the UK this year, for example, partly drove unexpectedly high UK inflation figures published last week, dampening expectations for further interest rate cuts this summer.

The report also suggests “high rates of inflation can directly alter election outcomes in modern democracies”.

Maximilian Kotz, a Marie Curie postdoctoral research fellow at Barcelona Supercomputing Center and the lead author of the report, said: It is clear the cost of living played a role in last year’s election in the US.

He added: “These effects are going to continue to become worse in the future. Until we get to net zero emissions extreme weather will only get worse, but it’s already damaging crops and pushing up the price of food all over the world.

“People are noticing, with rising food prices No 2 on the list of climate impacts they see in their lives, second only to extreme heat itself.

Read more: https://www.theguardian.com/business/2025/jul/21/rising-food-prices-driven-by-climate-crisis-threaten-worlds-poorest-report-finds

The study referenced by the article (I think);

Climate extremes, food price spikes, and their wider societal risks

Maximilian Kotz, Markus Donat, Tom Lancaster, Miles Parker, Pete Smith, Anna Taylor Smith and Sylvia H Vetter

Accepted Manuscript online 13 June 2025 • © 2025 The Author(s). Published by IOP Publishing Ltd

Article information

Abstract

2024 was the hottest year on record, with global temperatures exceeding 1.5°C above preindustrial climate conditions for the first time and records broken across large parts of Earth’s surface. Among the widespread impacts of exceptional heat, rising food prices are beginning to play a prominent role in public perception, now the second most frequently cited impact of climate change experienced globally, following only extreme heat itself. Recent econometric analysis confirms that abnormally high temperatures directly cause higher food prices, as impacts on agricultural production translate into supply shortages and food price inflation. These analyses track changes in overall price aggregates which are typically slow-moving, but specific food goods can also experience much stronger short-term spikes in response to extreme heat. In this perspective, we document numerous examples from recent years in which food prices of specific goods spiked in response to climate extremes. By evaluating the extremity of the associated climate conditions, we thereby build a global and climatological context for this phenomenon. We further review the knock-on societal risks which these effects may bring with the ongoing intensification of extremes under climate change. These range from increasing economic inequality and the burden on health systems, as well as destabilising monetary and political systems. We discuss challenges and priorities for research and policy to address these risks.

Read more: https://iopscience.iop.org/article/10.1088/1748-9326/ade45f/meta

The main study hilights the risk for low income households;

A catalyst for wider societal risks

Importantly, these climate-driven food price spikes can aggravate risks across a range of sectors of society. First, rising food prices have direct implications for food security, particularly for low-income households. This can result in a) households spending the same but buying less (either going hungry or depending on sources of charity); b) spending the same but buying cheaper options (typically cutting out nutritious foods like fruits and vegetables which are more expensive sources of calories) c) spending an even higher proportion of their income on food (with knock on effects on other areas of essential expenditure). These effects can be strongly regressive given the substantial disparities in the share of income spent on food by low- and high-income households. For example, in the USA the lowest income quintile spends approximately 33% of income on food compared to 8% in the highest income quintile. The fact that larger price increases occur in hotter and typically poorer countries will further amplify these effects

Fourth, food price inflation associated with climate-extremes may come to bear increasing political relevance. Anecdotal evidence from across history often cites food price increases as a precursor to political unrest and social upheaval (from the French and Russian revolutions of the 18th and 20th centuries, to the 2008/09 food crisis and 2011 Arab Spring). Such links are substantiated further by evidence showing a robust relationship between food prices and social unrest at monthly time-scales. Moreover, high rates of inflation can directly alter election outcomes in modern democracies. For example, high inflation reduced support for incumbent Democrats in the 2024 US election, and boosted support for extremist, anti-system and populist parties in elections held in advanced economies since 1948. These effects can be particularly strong when inflation affects real wages, as is the case with food prices.

Read more: Same link as above

The suggestion climate change is a major driver of food inflation is absurd, given the impact climate policies in the USA and elsewhere have on farm input and food distribution prices. For example California, arguably the most extreme green state in the union, farmers and truckers pay more for diesel that pretty much anywhere else in the USA. Such prices are a consequence of California’s regulatory hostility towards fossil fuel.

EIA Diesel Prices
EIA diesel prices. Source EIA.gov

These higher input prices, driven by state regulations, also appear to be impacting food prices in California, along with all the other environmental regulations California inflicts on farmers. California with its benign climate and fertile farmlands should have the cheapest food prices in the union, but that isn’t the case.

Grocery Basket Prices by State
Grocery Basket Prices by State. Source World Population Review, Fair Use, Low Resolution Image to Identify the Subject.

Obviously diesel prices aren’t the only factor, California’s overregulation of industry and radical minimum wage policies also play a part. But diesel prices are important to farming and shipping of produce.

California governor Gavin Newsom appears to have belatedly realised his administration could be the next victim of climate policy inflation voter backlash, if California does not change course.

And of course there is the fact that overall global farm yields are rising, a direct contradiction of Kotz’s claims that global warming is harming food production. Farming has always been susceptible to weather. Temporary shortages caused by individual weather events are blips which have no long term impact on rising global agricultural productivity.

Extended crop yield meta-analysis data do not support upward SCC revision

Scientific Reports volume 15, Article number: 5575 (2025) Cite this article

Abstract

The Biden Administration raised its Social Cost of Carbon (SCC) estimate about fivefold based in part on global crop yield decline projections estimated on a meta-analysis data base first published in 2014. The data set contains 1722 records but half were missing at least one variable (usually the change in CO2) so only 862 were available for multivariate regression modeling. By re-examining the underlying sources I was able to recover 360 records and increase the sample size to 1222. Reanalysis on the larger data set yields very different results. While the original smaller data set implies yield declines of all crop types even at low levels of warming, on the full data set global average yield changes are zero or positive even out to 5 °C warming.

Read more: https://www.nature.com/articles/s41598-025-90254-2

But let’s say I’m wrong. Lets play a thought experiment – what if climate driven food price inflation is a major factor?

Kotz admits that in a climate ravaged world, the most important factor in whether people get to eat regularly is personal wealth. Instead of gambling your nation’s future on an elusive global climate agreement, the safest solution to such a threat is to implement aggressive pro-growth policies, to lift as many of your own people as possible out of poverty.

There has never been and will never be a meaningful global climate agreement, so it is futile to hope the future will be any different. No nation would choose mass starvation over cheating on any future climate agreement.

Past agreements, implemented at great cost to those nations which took them seriously, had no impact on the global rise of global CO2. There is no reason to believe future agreements will be any different.

Mauna Loa CO2 Levels
Original source NOAA, annotated to show significant geopolitical climate events.

Lifting your own people out of poverty regardless of CO2 emissions would shield your own people from any climate disruption. And of course, if all nations followed the same strategy, and focussed on economic growth and boosting agricultural productive capacity rather than smashing their economies with carbon quotas, there would be more than enough global wealth to take care of any remaining poor people. Everyone would have enough to eat.

This is only a thought experiment. The claim we face an agricultural climate crisis is absurd, there is no evidence global warming and CO2 has had any negative impact on agriculture. Even NASA has repeatedly admitted the world is visibly greening.

My point is, Kotz’s claims fail on multiple levels. Not only is his claim that climate change is damaging agriculture not supported by the evidence, Kotz’s suggested remedy of attempting to achieve Net Zero also does not make sense. And while food price inflation did cause a drop in support for Democrats, that food price inflation was because of Democrat policies, not because of climate change.

The only safe solution, as always, is to maximise economic growth, to maximise our capacity to deal with whatever the future throws at us.


Discover more from Watts Up With That?

Subscribe to get the latest posts sent to your email.

via Watts Up With That?

https://ift.tt/rqVgsGS

July 21, 2025 at 08:10PM

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

image-8

See Also Worst Threat: Greenhouse Gas or Quiet Sun?

June 2025 SH and Tropics Lead UAH Temps Lower banner-blog

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.

via Science Matters

https://ift.tt/krEuV7Q

July 21, 2025 at 07:05PM