11.06.2026

Fuel on the fire

An important study shows that human-driven global warming is accelerating. As a consequence we will soon see the planet cross key tipping points, writes Eddie Ford

While generalised nuclear conflagration is the greatest immediate danger to human civilisation, the climate crisis poses a permanent threat, unless its very worst aspects are somehow ameliorated by drastic action. However, a recent study argues that the rate of global warming has risen sharply, not slowed down, thus bringing forward the various climate deadlines with potentially disastrous results for humanity.¹

Hence the paper by Grant Foster and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research, published in Geophysical Research Letters in March 2026, which locates warming at about 0.35°C per decade since 2015 - as opposed to an average of around 0.2°C per decade since the 1970s.² In other words, this is around three-quarters higher, with the paper’s authors describing it as the fastest decadal warming since the instrumental record began in 1880. Of course, the significance is that, if this pace were to hold at the same rate, the world would pass 1.5°C of long-term warming - the central target (or limit) of the Paris Agreement - around 2030.

We should not be surprised, of course, seeing that 2024 was the hottest year on record. According to the World Meteorological Organisation, for instance, the global average surface temperature that year was 1.55°C above the 1850-1900 average - based on six international datasets that are used to reach the consolidated global figure.³ 2024 saw exceptional land and sea surface temperatures, and ocean heat, while the previous 10 years (2015-24) were the 10 warmest on record.

Noisy

Anyway, what did the study paper actually measure? Essentially, the raw temperature record is “noisy” - meaning that El Niño, La Niña, volcanic eruptions and the roughly 11-year solar cycle all push global temperatures up and down by amounts that are not necessarily to do with the overall long-term trend. What Foster and Rahmstorf did by using various methods was remove or subtract estimates of these three influences from five global temperature datasets, following an approach they first pioneered in 2011.

What was then left, they claim, makes the global temperature curve “less variable” and shows a statistically significant acceleration, beginning around 2015. The last point is the real substance, of course, as previous attempts to detect acceleration in global temperatures had not reached the 95% confidence threshold scientists usually need - at least when it comes to climate science - to treat something as truly significant or a reframing of the debate. Another recent paper co-authored by James Hansen, the US climatologist who publicly sounded the alarm back in the 1980s, also concluded global warming is speeding up, although he did not do a statistical significance test. But the new paper says it has finally cleared that bar, once the short-term noise is stripped out, and naturally the peer-reviewed full paper by Foster and Rahmstorf lays out exactly the methodology they used.

Their summary points out that “warming proceeding faster is not unexpected by climate models”, but it “shows how insufficient the efforts to slow and eventually stop global warming under the Paris Climate Accord have so far been” - which communists would regard as a massive understatement, given that the ruling class has done the very opposite of what is needed. Runaway climate change will inevitably start to exceed the ability of humans and ecosystems to adapt, if left unchecked.

Although not involved in the research, Katharine Hayhoe, an atmospheric scientist at Texas Tech University, calls the study’s methodology “careful and meticulous”.⁴ She compares the atmosphere to a swimming pool, where the water is equivalent to carbon dioxide in the atmosphere, and humans have essentially stuck a hose into the pool and every year been turning up the faucet - so the water is rising faster and faster. In a nutshell, she writes, Foster and Rahmstorf in this study are “finally detecting what scientists have long predicted”. In broad agreement is Claudie Beaulieu, an Ocean and Earth sciences assistant professor at the University of California, saying it was a sign of the study’s accuracy that all five data sets showed an acceleration of warming, but pointed to possible limitations - particularly at how effective the scientists actually were in removing the influence of El Niño, volcanic eruptions and solar changes. For Beaulieu, continued monitoring will be essential to determine if this is “a genuine and lasting shift, or a transient feature of natural variability”.

Debate

Given that this is a scientific debate, not a dogmatic one, there is no settled consensus, but different and contending points of view. There are those, it goes without saying, who argue that the underlying warming rate has not changed at all. Much of the disagreement, it seems, goes back to a single awkward year, 2023 - that registered at about 1.45°C above pre-industrial levels - far enough above the previous record that, even when you combine El Niño and steady greenhouse warming together, it still struggles to account for the size of the jump. One possible explanation put forward by a group of scientists in the Science journal is a record-low planetary albedo - ie, the share of incoming sunlight Earth reflects back to space - driven mainly by a decline in low cloud cover over parts of the tropics and northern mid-latitudes.⁵ Now, whether that cloud loss is a passing fluctuation, a consequence of the aerosol cuts or a feedback from warming itself has not yet been resolved.

Regardless of the albedo debate, Michael Mann, a climate scientist at the University of Pennsylvania, has challenged the Foster and Rahmstorf thesis. He thinks there is no evidence of acceleration over the past 10 years, but rather that the recent run of record years is down to something more specific: a drop in industrial aerosol pollution, particularly sulphur, that had been masking part of the warming greenhouse gases were already producing. Therefore, by this argumentation, the planet is warming at a roughly constant rate until carbon emissions reach net zero - which is bad enough on its own, he adds. This is not something peculiar to Mann, it has to be said, but a well-documented phenomenon. Simply put, sulphate aerosols reflect sunlight directly and help seed bright, reflective, low clouds, so cutting them removes a cooling effect rather than adding a fresh source of heat.

We can see this most clearly with shipping. In 2020 there was a public-health measure aimed at cutting air pollution, which saw the International Maritime Organisation sharply lowering the permitted sulphur content of marine fuel - causing sulphur dioxide emissions from large ships to fall by about 80%-85%. Accordingly, the reflective ‘ship tracks’ over busy ocean lanes thinned, and the cooling they had provided faded with them. Unsurprisingly, estimates of how much warming this unmasks vary widely - from a few hundredths of a degree to around 0.1°C this decade, depending on which assumptions you start from - with the effect concentrated in the northern hemisphere, where most shipping runs.⁶ With far less of this ‘good’ pollution, to put it another way, it looks like there has been a spike in temperatures - but that would be mistaken, or so argues Michael Mann.

As for Berkeley Earth, it took a studied ‘middle position’ in its report for 2025.⁷ This involves placing 2025 as the third warmest year on record and kept the long-run trend since 1980 at about 0.2°C per decade, treating the 2023-25 spike as a likely sign of faster warming - with a warning that the past rate may no longer be a reliable predictor of the next decade, since natural and human causes are tangled together in complex ways. Berkeley Earth also makes the important point that in some ocean regions the sulphur cuts have largely run their course, which limits how much additional warming they can still unmask.

Deadlines

We need to emphasise once again that, because 2024 was the first calendar year to average more than 1.5°C above pre-industrial temperatures, that is not the same as breaching the Paris target - which is defined over a multi-decade average rather than any one hot year. After all, the acceleration argument rests on a small number of recent years - precisely why it is so contested. A run of cooler years would weaken it and continued record warmth would strengthen it. The 2026 and 2027 figures for El Niño will obviously tell us more than any single paper, and further research will be required to work out how much of the recent heat the shipping aerosol cuts and the cloud changes are actually responsible for.

But, when it comes down to it, warming is running at least as fast as expected - maybe even faster - and shows no sign of slowing. Quite the opposite. Beyond 1.5°C warming, which we have now reached, there is a grave risk that the planet will cross key tipping points - from the dieback of the Amazon rainforest to the thawing of Arctic permafrost, which would further accelerate warming in a negative feedback loop. The young Stefan Rahmstorf - as a scientist in the 1990s, at a time when the facts of climate change started to become clear - “could not have imagined that policymakers would get such clear evidence that we are heading into a very serious disaster for humanity and not act” - using his words. But that is essentially what has happened - especially true in the USA, where the government “basically just denies reality”.⁸

But it is not just the USA, of course. For all his fine words, Sir Keir Starmer seems to be planning to cut net-zero spending to fund a defence boost - sources suggest that this could involve scaling back the £9.4 billion that the government committed to ‘carbon capture and storage’ projects in the spending review last year. It is also claimed that the prime minister blames Ed Miliband, the energy secretary, for briefing against him in the wake of Labour’s disastrous local election results.⁹ The defence investment plan - due to be announced this week before a Nato summit next month in Ankara - could possibly be delayed even further. Britain is the second bottom in a Nato league table that ranks member-states based on the extent to which they are meeting their rearmament promises.

David Lammy, deputy prime minister, insisted the plan would be “absolutely clear” before the Nato summit - just you see! When asked on the BBC’s Sunday with Laura Kuenssberg if he would be happy to give up some of his own budget as justice secretary to divert money to the armed forces, Lammy said defence was the “first purpose” of the nation, so “the money will be found” to meet spending commitments - the UK government is expected to produce a fully-funded plan, spelling out what it can and will contribute to Nato beyond its Trident nuclear missile system.

Starmer is far more concerned with Britain’s position in the imperialist pecking order than devoting the resources needed in an attempt to restore the natural conditions, which we humans, being part of nature, depend upon for our very existence.