Abstract
Marine heatwaves, extended periods of elevated sea surface temperature, impact society and ecosystems, and deeper understanding of their drivers is needed to predict and mitigate adverse effects. These events can be particularly severe in the Mediterranean Sea during the summer although the factors that control their occurrence and duration are not fully known. Here we use a comprehensive multi-decadal macroevent dataset and a cluster analysis to investigate the atmospheric dynamics preceding the largest summer marine heatwaves in the Mediterranean Sea. Our study identifies the favourable conditions leading up to marine heatwave peaks and reveals that their main synoptic cause in the Mediterranean Sea is the combined effect of persistent subtropical anticyclonic ridges and associated weakening of prevailing wind systems. When persistent subtropical ridges are established over the region, the resulting decrease in wind speeds causes a substantial reduction in latent heat loss to the atmosphere, which accounts for over 70% of the total heat flux in affected regions. This reduction, combined with a moderate increase in short-wave radiation, generates and intensifies marine heatwaves. This synergistic relationship represents a key mechanism that is critical for skilfully predicting such atmospheric circulation patterns and realistically simulating their impacts on the marine environment.
Significance
Affecting global sea-level rise, mass loss from Arctic glaciers has implications far beyond their geographical location and is relevant for related geosciences, as well as ecological and biosciences and the general public. Combining in situ observations, remote sensing, and modeling, we quantify the mass loss of all glaciers on Svalbard during the record-warm summer of 2024, that by far exceeds previous levels. Analyzing historic temperature records and projections of future climate, we find that temperature levels as in 2024 represent a rare situation for contemporary climate conditions but will be frequently reached in a few decades. We suggest that the summer of 2024 in Svalbard serves as an analogue for the widespread meltdown of Arctic glaciers in a warmer world.
Abstract
A record-breaking melt season affected the Arctic glaciers of Svalbard in summer 2024 by a substantial margin. Across the entire archipelago, glacier melting corresponded to an anomaly of up to four SD and exceeded any previous observation. The pan-Svalbard mass loss in summer 2024 amounts to ~61.7 ± 11.1 Gt and corresponds to 1% of the total ice volume on Svalbard and is comparable to that of the Greenland ice sheet (55 ± 35 Gt), which occupies an area about 50 times larger. Altogether, Svalbard and other glacier regions surrounding the Barents Sea lost 102.1 ± 22.9 Gt of ice in a single year and contributed 0.27 ± 0.06 mm (of which 0.16 mm alone is due to Svalbard) to global sea-level, putting the circum-Barents region among the strongest contributors to global sea-level rise in 2024. Most of the 2024 glacier melt occurred during a 6-wk period of persistent atmospheric circulation pattern causing record-high air temperatures, an event with an extremely low recurrence interval under current climate conditions. However, future climate projections suggest that such temperature levels will become increasingly commonplace by the end of the 21st century, potentially even surpassing those of 2024. Svalbard’s summer of 2024 serves as a forecast for future glacier meltdown in the Arctic, offering a glimpse into conditions 70 y ahead.
Droughts are becoming more severe and widespread across the globe. But it's not just changing rainfall patterns that are to blame. The atmosphere is also getting thirstier.
In a new study published in Nature, my colleagues and I show that this rising "atmospheric thirst" – also known as atmospheric evaporative demand (AED) – is responsible for about 40% of the increase in drought severity over the last four decades (1981-2022).
Imagine rainfall as income and AED as spending. Even if your income (rainfall) stays the same, your balance goes into deficit if your spending (AED) increases. That's exactly what's happening with drought: the atmosphere is demanding more water than the land can afford to lose.
As the planet warms, this demand grows – drawing more moisture from soils, rivers, lakes, and even plants. With this growing thirst, droughts are getting more severe even where rain hasn't significantly declined.
The process of AED describes how much water the atmosphere wants from the surface. The hotter, sunnier, windier and drier the air is, the more water it requires – even if there isn't less rain.
So even in places where rainfall hasn't changed much, we're still seeing worsening droughts. This thirstier atmosphere is drying things out faster and more intensely and introducing more stress when this water is not available.
Our new analysis reveals that AED doesn't just make existing droughts worse – it expands the areas affected by drought. From 2018 to 2022, the global land area experiencing drought rose by 74%, and 58% of that expansion was due to increased AED.
Our study highlights that the year 2022 stood out as the most drought-stricken year in over four decades. More than 30% of the world's land experienced moderate to extreme drought conditions. In both Europe and east Africa, the drought was especially severe in 2022 – this was driven largely by a sharp increase in AED, which intensified drying even where rainfall hadn't dropped significantly.
In Europe alone, widespread drying had major consequences: reduced river flows hindered hydropower generation, crop yields suffered due to water stress, plus many cities faced water shortages. This put unprecedented pressure on water supply, agriculture and energy sectors, threatening livelihoods and economic stability.
My team's new research brings clarity to the dynamics of drought. We used high-quality global climate data, including temperature, wind speed, humidity and solar radiation – these are the key meteorological variables that influence how much water the atmosphere can draw from the land and vegetation. The team combined all these ingredients to measure AED – essentially, how "thirsty" the air is.
Then, using a widely recognised drought index that includes both rainfall and this atmospheric thirst, we could track when, where and why droughts are getting more severe. With this metric, we can calculate how much of that worsening is due to the atmosphere's growing thirst.
The future implications of this increasing atmospheric thirst are huge, especially for regions already vulnerable to drought such as western and eastern Africa, western and south Australia, and the southwestern US where AED was responsible for more than 60% of drought severity over the past two decades.
Without factoring in AED during drought monitoring and planning, governments and communities may underestimate the true risk they face. With global temperatures expected to rise further, we can expect even more frequent and severe droughts. We need to prepare. That involves understanding and planning for this growing atmospheric thirst.
Driving drought
Knowing what is causing droughts in each specific location enables smarter climate adaptation. AED must be a central part of how we monitor, model and plan for drought.
Identifying the specific drivers of drought is essential for tailoring effective ways to cope with drought. If droughts are mainly due to declining rainfall, then the focus should be on water storage and conservation. But if AED is the main driver – as it is in many places now – then strategies must address evaporative loss (i.e. the amount of water lost from the surface and plants to the atmosphere) and plant water stress. This might involve planting drought-resistant crops, constructing irrigation systems that use water more efficiently, improving soil health or restoring habitats to keep moisture in the land.
As our research shows, rising AED – driven by global warming – is intensifying drought severity even where rainfall hasn't declined. Ignoring it means underestimating risk.
• President Donald Trump said the U.S. will not approve wind or solar power projects.
• Trump has tightened federal permitting for renewables with Interior Secretary Doug Burgum now having the final say.
• Renewable companies fear that projects will no longer receive permits that were once normal course of business.
President Donald Trump on Wednesday said his administration will not approve solar or wind power projects, even as electricity demand is outpacing the supply in some parts of the U.S.
"We will not approve wind or farmer destroying Solar," Trump, who has complained in the past that solar takes up too much land, posted on Truth Social. "The days of stupidity are over in the USA!!!"
The president's comment comes after the administration tightened federal permitting for renewables last month. The permitting process is now centralized in Interior Secretary Doug Burgum's office.
Renewable companies fear that projects will no longer receive permits that were once normal course of business. The president's comments Wednesday will likely heighten those concerns.
Trump blamed renewables for rising electricity prices in the U.S. Prices have risen on the nation's largest grid, PJM Interconnection, as rapidly growing demand from data centers and other industries faces a tight power supply as resources such as coal plants are retired.
PJM Interconnection saw prices for new power capacity rise 22% compared to last year in an auction held last month. PJM covers 13 states across the Mid-Atlantic and parts of the Midwest and South.
But solar and battery storage are the power sources that can ease the supply-and-demand gap the quickest, as they make up an overwhelming majority of the projects in line to connect to the grid, according to data from Lawrence Berkeley National Laboratory.
Trump has launched a sweeping attack on renewables since taking office. His One Big Beautiful Bill Act terminates the investment and production tax credits for wind and solar by the end of 2027. Those credits have played a key role in the expansion of renewable energy in the U.S.
The president's steel and copper tariffs have also increased the costs of solar and wind projects, renewable companies say.
The U.S. Department of Agriculture on Tuesday ended its support for solar on farmland.
Abstract
Several, more recent global warming projections in the coupled model intercomparison project 6 contain extensions beyond year 2100–2300/2500. The Atlantic meridional overturning circulation (AMOC) in these projections shows transitions to extremely weak overturning below the surface mixed layer (<6 Sv; 1 Sv = 106 m3 s−1) in all models forced by a high-emission (SSP585) scenario and sometimes also forced by an intermediate- (SSP245) and low-emission (SSP126) scenario. These extremely weak overturning states are characterised by a shallow maximum overturning at depths less than 200 m and a shutdown of the circulation associated with North Atlantic deep water formation. Northward Atlantic heat transport at 26°N decreases to 20%–40% of the current observed value. Heat release to the atmosphere north of 45°N weakens to less than 20% of its present-day value and in some models completely vanishes, leading to strong cooling in the subpolar North Atlantic and Northwest Europe. In all cases, these transitions to a weak and shallow AMOC are preceded by a mid-21st century collapse of maximum mixed-layer depth in Labrador, Irminger and Nordic Seas. The convection collapse is mainly caused by surface freshening from a decrease in northward salt advection due to the weakening AMOC but is likely initiated by surface warming. Maximum mixed-layer depths in the observations are still dominated by internal variability but notably feature downward trends over the last 5–10 years in all deep mixing regions for all data products analysed. This could be merely variability but is also consistent with the model-predicted decline of deep mixing.
If the US is going to build massive new LNG terminals in the Gulf of Mozambique or whatever that body of water between Texas and Florida is called today, it will need plenty of customers for that climate-killing fuel. By definition, exports are not intended for domestic customers, so all that lovely liquid death is intended for people and industries in places other than America.
When the so-called president declared an “energy emergency” earlier this year, he meant that he intended to reward the fossil fuel interests who spent so much money to help him get elected. When he proclaimed his intention to establish “energy dominance,” he meant the US would now supplant OPEC as the top dog on the international energy stage.
During the now infamous three-hour cabinet meeting last week, where all the MAGA faithful competed to be the biggest suck-up to the Pharaoh Of The Potomac, our Dear Leader crowed that he was trying his best to get other nations that have clean energy and climate initiatives as part of their national planning to see the error of their ways.
“I’m trying to have people learn about wind real fast, and I think I’ve done a good job, but not good enough because some countries are still trying,” he said, and added that countries were “destroying themselves” with wind energy. “I hope they get back to fossil fuels,” he said. According to a report by Lisa Friedman of the New York Times, two weeks ago, the failing administration promised to punish countries by imposing tariffs, visa restrictions, and port fees on them if they vote for a global agreement to slash greenhouse gas emissions from the shipping sector.
A few days later in Geneva, the Trump US joined Saudi Arabia and other oil-producing countries to oppose limits on the production of petroleum-based plastics. “They are clearly using various tools in an attempt to increase the use of fossil fuels around the world instead of decrease,” said Jennifer Morgan, Germany’s former special envoy for climate action,
Chris Wright, the fracking billionaire who is now the head of the US Energy Department, warned that the United States could end its support for the International Energy Agency because it predicted that global demand for oil would peak this decade instead of continue to climb. He proclaimed to Europeans in April that they faced a choice between the “freedom and sovereignty” of abundant fossil fuels and the policies of “climate alarmism” that would make them less prosperous.
Taylor Rogers, a White House spokesperson, said the goal of the administration was “restoring America’s energy dominance, ensuring energy independence to protect our national security and driving down costs for American families and businesses. The…..administration will not jeopardize our country’s economic and national security to pursue vague climate goals.”
Most CleanTechnica readers will be surprised to hear that taking prudent steps to keep the Earth habitable for humans is a “vague climate goal,” but that is the sort of drivel one gets form people infected with a MAGA mind virus.
Alarm On The Continent
Many European officials are alarmed by the amount of pressure the US is exerting on their countries, especially in light of the catastrophic heat waves that have blanketed the Continent in recent years. Lisa Friedman writes that the vast majority of scientists agree a transition away from oil, gas, and coal and toward clean energy resources like wind, solar, geothermal, and hydro power is essential to avoid making climate change more severe.
“At this moment in time it is absolutely imperative that countries double down, triple down, on their collaboration in the face of the climate crisis to not allow the active efforts for a fossil fuel world by the Trump administration succeed,” Jennifer Morgan said.
The alleged president has been pursuing a vendetta against wind energy ever since Scotland approved an offshore wind installation that is visible from his golf emporium in that country 14 years ago. When he met with Ursula von der Leyen, the president of the European Commission, earlier this year, he denounced wind power as a “con job” and claimed that wind turbines drive birds “loco.”
Shortly thereafter he met with UK Prime Minister Keir Starmer and called wind energy “a disaster.” He added that “Wind needs massive subsidies, and you are paying in Scotland and in U.K., and in all over the place where they have them, massive subsidies to have these ugly monsters all over the place.”
This maladministration is “actively trying to undermine countries” on global warming, David Goldwyn, an energy consultant, told Friedman. Several diplomats from other countries said that the administration has used increasingly aggressive tactics to influence international energy policies.
In February, Chris Wright told a conference in London via video that net zero is a “sinister goal” and criticized a British law that makes becoming net zero by 2050 a national goal. In March, the maladministration denounced the United Nations Sustainable Development Goals, which were adopted by nations unanimously in 2015 and include such woke ideas as addressing poverty, hunger, and climate change. The administration said “the government of the United States must refocus on the interests of Americans,” which apparently means combating “climate ideology.”
Just this month, the US government announced it would reject the agreement reached by the members of the International Maritime Organization to impose a fee on carbon emissions from shipping. The US said it would “not hesitate to retaliate or explore remedies for our citizens” against other countries that support the shipping fee.
“You see a more systematic attempt to be a fossil fuel first strategy to everything that they do,” Jake Schmidt, director of international programs at the Natural Resources Defense Council, told Friedman. He added that the administration may slow the transition to clean energy by other countries but cannot stop it.
Diana Furchtgott-Roth, director of the Center for Energy, Climate and Environment at the Heritage Foundation, which spawned the agenda of grievance and hate known as Project 2025, told Friedman the administration was doing the right thing by pressuring countries to reject renewable energy.
“Europe is coming to the United States saying, ‘Help defend us against Russia, help us with Ukraine,’” she said. “Where at the same time, they’re spending $350 billion a year on green energy investments that are slowing their economies. It doesn’t seem to make very much sense to the administration. I think we’re going to see more pressure.”
Paul Krugman On Allies & Power
Paul Krugman is highly critical of how the US is alienating its allies. On August 29, he wrote on Substack, “The Pax Americana that emerged after World War II — and basically ended on January 20, 2025 — was, in many ways, an American Empire…. We built international economic and military alliances to support a world order in effect designed to U.S. specifications.
“In 1947 a conference in Geneva established the General Agreement on Tariffs and Trade, which set the ground rules for — tariffs and trade. The GATT in turn became the foundation for the World Trade Organization, established in 1994.
“NATO is another international institution create by the US in partnership with its allies. It has always been a partnership of equals. While the NATO military commander has always been an American, the Secretary General has always been a European,” Krugman wrote.
“The current occupant of the White House clearly has no use for subtlety and understatement. In just 7 months Trump has completely ripped up the foundations of the Pax Americana,” Krugman said. “Almost all his tariffs are clearly in violation of the GATT, yet Trump has vandalized the world trading system as casually as he has paved over the Rose Garden. We haven’t yet had a test of whether he would honor our obligations under NATO, but he’s said that his willingness to abide by the most central obligation, the guarantee of mutual defense, ‘depends on your definition.’
“Trump’s foreign policy doctrine appears to be Oderint dum metuant — let them hate as long as they fear — supposedly the favorite motto of the Emperor Caligula. America, he seems to believe, is so powerful that it doesn’t need allies; he can bully the world into doing his bidding.
“Whatever Trump may imagine, the world doesn’t fear us. For example, Trump may have imagined that his tariffs would bring India crawling to him, begging for relief. Instead, India seems to be moving to closer ties with China. In fact, not only does the world not fear us; increasingly, it doesn’t need us. This is even true for nations that used to depend on U.S. military aid.
“One of the many problems with the slogan Make America Great Again was that America already was great. Now, not so much. In a world in which America is no longer the dominant economic and military power it once was — measured by purchasing power, China’s economy is already 30 percent larger than ours — our role in world affairs depends, even more than it did in the past, on having willing allies who trust our promises.”
Krugman ends with this analysis: “We used to be very good at having allies. But Trump has flushed all of that down the golden toilet.”
Alienating Allies Is A Fool’s Game
The damage being done is incalculable. After the first attempt at governing by the man who would be king, the world decided to forgive and forget when adults started running the US government again. They thought America had learned its lesson. They will not be so quick to forget after Americans decided last November, “Yeah, we want more of that.” Repairing the damage from this clown show will take decades, during which America’s leadership on the world stage will be like that of all former empires — nattering on the sidelines about how things used to be and plotting how to regain their former prominence.
The deliberate assault on America’s allies is likely to benefit one nation most of all — China. With its focus on clean energy and electrification of all segments of its economy, China will become the leader of the world’s nations, not least because the US chose to give up its pursuit of education and science to concentrate on grievances and settling scores — real and imagined.
That is not to say that China is prefect; it is not. But it is intent on preserving the Earth as a place where humans can continue to flourish. The US, on the other hand, is doing everything it can to ramp up the destruction of the environment in every way possible. That is a strategy sure to make other nations turn their backs on America and go in search of other allies.
In retrospect, Project 2025 won’t make the US great, it will make the US irrelevant. When historians ask who is responsible for the destruction of America, their search will lead them to the Heritage Foundation and its paterfamilias, Charles Koch. Trump is merely a puppet; Koch is the one pulling the strings. If you are in doubt about the accuracy of that assertion, pick up a copy of Jane Mayer’s Dark Money and be prepared to be frightened out of your wits.
Under the influence of Koch and the MAGAlomaniacs, the US will soon find itself on the outside looking in. When it needs a friend, no one will answer the call. Then and only then with the full extent of the damage done to America by this administration become apparent for all to see.
Abstract
Fossil-fuel burning is heating the planet with catastrophic consequences for its habitability and for the natural world on which our existence depends. Halting global warming requires rapid and deep decarbonization to “net zero” carbon dioxide (CO2) emissions, which needs to be achieved by 2050 if warming is to remain within the limits set out by the 2015 Paris Agreement. However, some scientists and engineers claim that a mid-century decarbonization target will not be reached, and they propose that we should focus on technological geoengineering “fixes” or “climate interventions” that could delay or mask some of the impacts of global warming. They often cite the need to slow warming in polar regions because they are experiencing rates of warming higher than the global average, with severe and irreversible projected consequences both locally (e.g., on fragile ecosystems) and globally (e.g., on sea level). Several geoengineering concepts exist for polar regions, but they have not been fully examined by the polar science community, nor integrated with an understanding of polar dynamics and responses. Here, we evaluate five of those polar geoengineering concepts and highlight the significant issues and risks relating to technological availability, logistical feasibility, cost, predictable adverse consequences, environmental damage, scalability (in space and time), governance, and ethics. According to our expert assessment, none of these geoengineering ideas pass scrutiny regarding their use in the coming decades. Instead, we find that the proposed concepts would be environmentally dangerous. It is clear to us that the assessed approaches are not feasible, and that further research into these techniques would not be an effective use of limited time and resources. It is vital that these ideas do not distract from the priority to reduce greenhouse gas (GHG) emissions or from the critical need to conduct fundamental research in the polar regions.
Key points
• Five geoengineering concepts proposed for the polar regions fail to meet the essential criteria required for them to be considered responsible approaches toward limiting the escalation of climate-related risks. These criteria include feasibility and likelihood of success.
• Geoengineering in sensitive polar regions would cause severe environmental damage and comes with the possibility of grave unforeseen consequences.
• Polar regions have complex environmental protection and governance frameworks that would probably reject polar geoengineering fieldwork and large-scale projects.
• Polar geoengineering would require hundreds of billions of dollars in initial costs, plus decades of ongoing maintenance, both of which are presently unavailable and highly unlikely to be secured over necessarily short timescales to address climate change.
• Geoengineering could be used by bad actors as a strategy to create the illusion of a climate solution without committing to decarbonization.
• Minimizing risk and damage from climate change is best achieved by mitigating its causes through immediate, rapid, and deep decarbonization, rather than attempting interventions in fragile polar ecosystems.
Abstract
Extreme event attribution assesses how climate change affected climate extremes, but typically focuses on single events1,2,3,4. Furthermore, these attributions rarely quantify the extent to which anthropogenic actors have contributed to these events5,6. Here we show that climate change made 213 historical heatwaves reported over 2000–2023 more likely and more intense, to which each of the 180 carbon majors (fossil fuel and cement producers) substantially contributed. This work relies on the expansion of a well-established event-based framework1. Owing to global warming since 1850–1900, the median of the heatwaves during 2000–2009 became about 20 times more likely, and about 200 times more likely during 2010–2019. Overall, one-quarter of these events were virtually impossible without climate change. The emissions of the carbon majors contribute to half the increase in heatwave intensity since 1850–1900. Depending on the carbon major, their individual contribution is high enough to enable the occurrence of 16–53 heatwaves that would have been virtually impossible in a preindustrial climate. We, therefore, establish that the influence of climate change on heatwaves has increased, and that all carbon majors, even the smaller ones, contributed substantially to the occurrence of heatwaves. Our results contribute to filling the evidentiary gap to establish accountability of historical climate extremes
