Global Warming...New Report...and it ain't happy news

Abstract

Understanding the history of Earth rotation variations and its connection to mantle dynamics is one of the most important problems is global geophysics. However, our knowledge of these variations—in particular those induced by climate on geological timescales—is limited due to both modeling deficiencies and the scarcity of paleoclimate data. In order to advance our understanding of this problem, here we first develop a new probabilistic deep learning methodology called Physics-Informed Diffusion Model (PIDM). We then use PIDM in conjunction with the recently available paleoclimate data—specifically, sea level variations since the Late Pliocene—to precisely reconstruct the history of climate-induced changes in the Earth's rotation rate (i.e., Length of Day variations:
LOD). We reconcile
LOD inferred from various climate models and paleoclimate proxies (i.e., geological records such as fossil benthic foraminifera and coral reefs). Based on our reconstructions of
LOD, we unravel (a) large-amplitude fluctuations due to Quaternary ice ages, surpassing the magnitude of the currently known processes including those of atmosphere, land hydrology, and core, (b) a previously unrecognized secular trend due to changes in the Earth's oblateness caused by the outset of Northern Hemispheric ice sheets, and (c) the almost unprecedented rate of increase in the length of day caused by
century climate change.

Editor’s summary

Global demand for wood products is increasing, as are calls for protecting tropical forests from deforestation. In boreal regions, where much of the forest has not been previously logged, demand has led to clear-cutting of such old, “primary” forest. Pascual et al. showed the potential impacts of clearing primary boreal forests by comparing the carbon storage of primary and secondary (previously logged) forests in Sweden. Including vegetation, dead wood, wood products, and soils, primary forests stored over 70% more carbon than secondary forests, a difference several times greater than previous estimates. These results reveal previously underappreciated value in protecting primary boreal forests. —Bianca Lopez


Abstract

Boreal forests provide considerable global land carbon storage and uptake, but they are being rapidly transformed to managed secondary forests, with poorly quantified implications for ecosystem carbon storage. Here we present data from extensive mapping and field inventories of carbon storage in primary forests in Sweden and use multiple methods to show that primary forests store ~72% (70 to 74% across methods) more carbon than managed secondary forests in vegetation, deadwood, soils, and harvested wood products combined. Soils constitute both the largest carbon store and the largest difference between these forest types. The total carbon storage difference between primary and managed secondary forests is 2.7 to 8.0 times larger than previous estimates. Our results challenge estimated past and future contributions of boreal forest management to atmospheric carbon dioxide concentrations.

Our home planet is struggling with a record energy imbalance, which is warming oceans to unprecedented levels, making weather more extreme and threatening health and food supplies, the World Meteorological Organization has warned.

The United Nations body confirmed 2015 to 2025 were the hottest 11 years ever measured, but a still bleaker message was that the rising temperature experienced by humans on the surface was only 1% of the faster-accumulating heat in the wider Earth system.

More than 90% of that excess is absorbed by the oceans, which experienced the highest heat content in history last year. The rate of ocean warming has more than doubled over the past two decades, compared with the average over the previous 45 years.

The authors of the latest annual State of the Global Climate report say this highlights the increasing vulnerability of a planet that is moving ever further out of balance as a result of human activity. The burning of oil, gas, coal and forests releases heat-trapping greenhouse gases such as carbon dioxide, methane and nitrous oxide, which are all at their highest level in at least 800,000 years.

This disrupts the planet’s energy equilibrium. In a well-functioning system, the amount of radiation entering and leaving the Earth system is roughly similar. But a heat surplus has been accumulating since at least 1960 and has noticeably accelerated in recent years.

This is tracked for the first time in the new report, which shows the Earth’s energy imbalance increased by about 11 zettajoules a year between 2005 and 2025, which is equivalent to about 18 times total human energy use. Last year it was more than double that average.

At present, humans and other life forms on the surface directly suffer only a small fraction of that energy backup because 91% is absorbed by oceans, 5% by the land, 1% warms the atmosphere, and 3% melts ice at the poles and on high mountains.

But even with only a tiny share of this extra energy, the world’s surface temperatures – which are the most commonly used measure of global heating – are climbing to alarming levels. Last year was the second- or third-hottest on record, depending on the dataset. World leaders say it is now inevitable the planet will – at least temporarily – breach the target of limiting heating to 1.5C above preindustrial levels set by the Paris agreement. They say the dire consequences are already evident in faltering harvests, worsening dengue outbreaks and increasingly severe heatwaves, forest fires and storms.

“The state of the global climate is in a state of emergency. Planet Earth is being pushed beyond its limits. Every key climate indicator is flashing red,” said the UN secretary-general, António Guterres. “Humanity has just endured the 11 hottest years on record. When history repeats itself 11 times, it is no longer a coincidence. It is a call to act.”

The effect on the oceans is still not fully understood, but the impacts are expected to be still more profound and long-lasting. Sea levels are rising at an accelerating pace, and sea ice is at its third-lowest level ever.

The authors of the paper said more of the heat is moving into the depths, which is affecting circulation and locking in the consequences for thousands of years.

Nearer the surface, heatwaves and acidification are a growing problem for corals and other marine life, while the melting of ice is pushing up sea levels and weakening the planet’s ability to reflect solar radiation back into space, thus adding to the energy imbalance.

There is no respite in sight. The Pacific is coming to the end of a La Niña phase, which is usually associated with cooler temperatures at the surface across much of the world. By the end of this year, forecasts suggest this could be replaced by an El Niño, which will bring more heating. “If we transition to El Niño we will see an increase in global temperature again and potentially to record levels,” said Dr John Kennedy, the lead author of the WMO report.

Abstract

Droughts and hot extremes, individually and in combination, are intensifying, driven by anthropogenic greenhouse gas emissions. However, a globally comparable and cross-national assessment of the future risks posed by these events remains a critical gap. Our analysis shows that under current policies, leading to ∼2.7°C warming by 2100, 28.5% ± 9.3% of the global population (roughly 2.6 ± 0.9 billion people) may face heightened compound hot-dry extremes. Based on present-day per capita emissions, the cumulative lifetime emissions of ∼3.4 average global citizens (or ∼1.2 average US citizens) could expose one individual to these conditions by the end of century. Tropical island nations are expected to experience the most severe increases in compound hot-dry extremes. More critically, low-income countries, despite contributing minimally to global emissions, are projected to suffer more frequently than high-income countries. These findings underscore the urgent need for equity-focused, immediate policy action to address the socio-economic disparities exacerbated by climate change.

Treasury Secretary Scott Bessent claimed on Tuesday that it was difficult to determine the actual causes of climate change, dismissing decades of science that has attributed global warming to the burning of fossil fuels. He instead called on international financial institutions to focus their attention on economic growth and alleviating poverty.

The comments came in remarks on the sidelines of the spring meetings of the International Monetary Fund and the World Bank. Mr. Bessent had previously ordered the World Bank to remove some of its climate finance targets and finance “all affordable and reliable sources of energy” including gas, oil and coal.

The Trump administration has reversed most of the spending on clean energy that was underway during the Biden administration and pushed ahead with policies that end restrictions on greenhouse gas emissions and aim to ramp up domestic production of fossil fuels.

President Trump last year called global warming a “hoax” and a “con job.” While the Treasury secretary did not go that far, his comments contradicted the scientific consensus about why the world’s climate is changing.

“Yes, the climate does change,” Mr. Bessent said, adding that “we are going through cycles, and I believe that it is very difficult to deconstruct the reasons around why anything changes.”

Leading scientists have rejected claims like Mr. Bessent’s, and noted that natural factors like the sun, volcanic eruptions and orbital cycles would be cooling the earth if not for human activity. Instead, about 200 years ago, after the start of the Industrial Revolution, the direction of global temperatures reversed and began rapidly warming.

“The only reason for the observed warming are human activities, and the biggest of those activities are the emissions of heat-trapping gases from burning fossil fuels,” said Katharine Hayhoe, an atmospheric scientist at Texas Tech University.

Average global temperatures are expected to rise 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial levels within the next decade. That would unleash dire impacts that include increased and more intense heat waves and heavy precipitation, melting of the world’s glaciers and ice sheets and a higher risk of severe wildfires.

The Earth has already warmed about 1.2 degrees Celsius (2.3 degrees Fahrenheit) since the Industrial Revolution, scientific estimates suggest.

The Trump administration has rejected both global and domestic efforts to address climate change. It has withdrawn from the Paris climate agreement, as well as the underlying treaty that convenes nations each year to seek solutions to the planet’s warming. It has ended U.S. participation in the United Nations’ scientific body and has withdrawn from a fund aimed at helping the world’s poorest countries cope with the impacts of rising seas and extreme weather fueled by the changing climate.

Critics of this approach argue that nations need to reduce their emissions and develop ways to adapt to climate change to avoid costly, catastrophic weather events that are growing in frequency. The drawbacks of the Trump administration’s focus on oil instead of renewable energy has been evident this year, as the war in the Middle East sent gasoline prices soaring.

Mr. Bessent’s partner in the discussion was Bjorn Lomborg, a Danish academic who argues that climate change is occurring but is not a crisis, and that poor nations require fossil fuels to develop. His work has been influential with members of the Trump administration, particularly Chris Wright, the energy secretary, who has referred to Mr. Lomborg as a friend.

On Tuesday Mr. Lomborg argued that the World Bank is making nations poorer by spending money on what he called a “climate fixation” and a push to transition away from fossil fuels.

“The money that the World Bank spends on the solar panel can’t be invested in health care or education,” Mr. Lomborg said, arguing the institutions “need to get back to making rational priorities.”

Mr. Bessent agreed and said policymakers instead needed to focus on how to “increase resiliency.” He argued that global financial institutions should emphasize economic growth, trade and development.

“We cannot have these elite beliefs get in the way,” Mr. Bessent said, referring to climate change.

Harjeet Singh, the founding director of the Satat Sampada Climate Foundation in India, said calling climate change an “elite” issue purposefully ignores the threats it poses to the world’s poorest. He pointed to 2022 floods in Pakistan that killed nearly 2,000 people and caused more than $40 billion in damage, caused by heavier than usual monsoon rains and melting glaciers that followed a severe heat wave, both linked to climate change.

“If you don’t integrate climate, any development gains are written in sand and washed away,” he said.

Trump administration officials have struggled to articulate their views on climate change and explain how they veer from the international scientific consensus.

The former World Bank president, David Malpass, resigned in 2023 after he appeared to deny the causes of climate change. Mr. Malpass was a senior Treasury Department official during Mr. Trump’s first term and struggled to balance embracing Mr. Trump’s climate views with the climate agenda of the bank.

When pressed about whether he accepted that man-made greenhouse gas emissions had created a worsening crisis, Mr. Malpass said, “I’m not a scientist.” After backlash about those comments, he later said he was not a denier, explaining, “It’s clear that greenhouse gas emissions are coming from man-made sources, including fossil fuels.”

Mr. Bessent suggested on Tuesday that most of the alarm about the economic impact of climate change was the result of a 2024 study that was published by the journal Nature that was retracted last year. After problems with the data in the study were discovered, the researchers determined that instead of a 62 percent decline in economic output by 2100 in a world where carbon emissions continue unabated, global output would be reduced by 23 percent.

“Everything was based on that,” Mr. Bessent said, overstating the degree to which global climate policy had been steered by a single study. “I don’t think that we can have this kind of short-termism. I think we have to stick with core principles.”

The US Treasury secretary said it is “difficult to deconstruct” the reasons for global warming, which he described as a belief of the “elite.”

Bessent Questions the Cause of Climate Change and Its Economic Toll (NYT, no paywall)

Quote:

Treasury Secretary Scott Bessent... instead called on international financial institutions to focus their attention on ...alleviating poverty.