They concluded that even when the models came close to getting the right EEI, they got there in the wrong way. They tended to have a lower increase in absorption and a lower increase in emission; in balance-sheet terms, less income and less outgoings, even if the gap between the two was almost the same. But if all the models were wrong in the same direction, some were wronger than others. And the most wrong all had one thing in common: low “climate sensitivity”. Climate sensitivity is a way of thinking about the sum of all feedbacks—an estimate of the temperature rise to be expected for a given increase in forcing. In 2021 the IPCC reckoned that the best estimate of this sensitivity, given understanding of forcing at the time, was 3°C, with a 90% chance of a value between 2°C and 5°C. Dr Myhre and his colleagues found that, when judged by their performance on the EEI, models with a sensitivity estimate of less than 2.94ºC could, with high confidence, be ruled out. The IPCC’s best estimate of climate sensitivity is, in other words, the lowest still plausible (see chart 2). Moreover, a recent study led by Gergana Gyuleva, a colleague of Dr Knutti’s at ETH Zurich, using a different measure of climate sensitivity, gets a similar result. A long-time champion of higher climate sensitivities is James Hansen of the Earth Institute at Columbia University. Dr Hansen, a veteran who has been working on climate models and climate sensitivity since the 1970s, thinks the answer to the question “forcings or feedbacks?” is a resounding both. Sulphate effects are big; climate sensitivity is high. As a result he believes warming is currently growing not at 0.27°C per decade, the rate Dr Forster and his colleagues currently calculate, but at a whopping 0.4°C a decade. On that basis he expects the current El Niño to make both this year and next the hottest on record (most prognosticators think that its full effects will make this happen only next year). His projections see warming since the 19th century reaching 2°C—and thus surpassing the limit enshrined in the Paris agreement on climate in 2015— by the end of the 2030s.
Few of Dr Hansen’s peers agree with all of this. They take issue with the way he derives his high climate sensitivity from analysis of the ice ages and the warm periods between them. According to Dr Armour the pattern of the warming at the end of the most recent ice age did not look like the pattern of warming being seen today. Most discussions of climate sensitivity deal in global averages. But it is becoming increasingly clear that patterns matter. The oceans are not warming homogeneously, and some parts of the world are better at losing heat than others. The classic example is the “warm pool” in the western Pacific. Surface heat drives powerful convection into the atmosphere above, producing towering thunderclouds. This convection moves heat up towards the top of the atmosphere very efficiently. And once there that heat is more easily lost to space as infrared. The planet gets a radiator; its climate sensitivity goes down. Work by Vince Cooper of MIT, a former student of Dr Armour, applies similar ideas to the end of the ice age. The bits of the sea surface which were most anomalously cold back then were in northern high-latitudes. And for a given amount of warming, a world where that warming is concentrated in the high-latitudes will have a higher climate sensitivity than a world of more homogeneous warming like today’s. The changes in global average temperature seen then do not imply particularly high sensitivity now. In fact, Dr Cooper thinks they suggest that today’s sensitivity is unlikely to be more than 4°C. But the importance of patterns does not lie only in the past. Dr Rugenstein and others have been working for some time on the problem that the patterns of warming found in climate models do not, by and large, reflect those seen in the real world. And some aspect of this disjunction might explain why the models are not matching the real EEI. At the Ringberg meeting the number of people who thought that pattern effects might yet explain the EEI was smaller than the “forcings are wrong” crowd, but larger than any other group.
Unfortunately, it is not clear quite what that explanation would look like— not least because, as Dr Stevens puts it, “No one knows what makes the patterns.” Are they the result of natural variability, with their arrangement over the past few decades—during some of which the warm pool radiator was working very well— largely a matter of chance? Or might they be explained through a mechanism that the models do not yet know how to capture? “My intuition”, says Dr Rugenstein, “is that the models’ ocean heat uptake is wrong.” This would lead to problems with the sea-surface temperature patterns. Getting models to mirror the way the ocean couples to the atmosphere is a longstanding problem, and one that looks hard to solve. But it matters immensely. The oceans of the dimming Earth have been absorbing ever more energy. They are storing up that energy. Understanding the processes involved is a matter of urgency—and a certain frustration. “What the last 25 years actually tell us about the next 25 years is open,” says Dr Rugenstein. “And that’s embarrassing as a field.” Last year Dr Stevens and Tiffany Shaw, a researcher at the University of Chicago who looks at predictions of regional climate change, published a paper called “The Other Climate Crisis”. The first climate crisis is familiar enough: the world is heating up quickly. The other crisis, they argue, is in climate science itself, where an accumulation of anomalies suggests that some assumptions needed questioning. Progress in understanding what the increasing amount of energy being stored in Earth’s land, sea and air system is actually going to do, they say, requires climate scientists to concentrate on the processes and predictions where models and data diverge the most. There is no more consequential divergence to get started with than the dimming of Earth. ■ For more coverage of climate change, sign up for the Climate Issue, our fortnightly subscriber-only newsletter, or visit our climate-change hub. This article was downloaded by zlibrary from https://www.economist.com//science-and-technology/2026/07/15/the-rate-at-which- earth-is-absorbing-energy-is-alarming-climate-scientists
Science & technology | Well informed How to train for a heatwave A nice, hot bath can go a long way July 16th 2026 ENGLAND’S football team set up camp in West Palm Beach, Florida, on June 1st, almost two weeks before the start of the 2026 World Cup. That was so the players, many of whom were used to training in the mild climate of Britain, could adapt to the blistering heat of the host nations. But as July has brought western Europe’s third heatwave of 2026, even those not competing in elite sports might wonder how they can train appropriately to beat the heat. Preparing for heat requires exposure to heat. That increases levels of blood plasma—the watery stuff which carries blood cells around the body— meaning the heart does not have to work as hard to pump blood, and can beat in a more leisurely manner for longer.
More plasma also improves blood flow to the skin. There, tiny sweat glands release water and electrolytes onto the skin’s surface, whence the water evaporates, cooling the body. As the body adapts to heat it lowers the temperature at which perspiration begins, as well as the amount of electrolytes lost. The best way to bring about such changes is “controlled hyperthermia”. Unfortunately, that involves being locked in a heat chamber for 90 minutes and monitored with a rectal thermometer. In the sweltering heat, participants spend 30 minutes exercising to raise their core body temperatures to a target value—usually 38.5°C. The next hour is then spent alternating between exercise and rest to keep their temperature fixed at the target. And you have to repeat this daily for five to seven days. Few people, however, have a heat chamber—or the necessary monitoring equipment—in their living room. Fortunately, scientists have devised methods more appropriate for everyday life. The simplest is to exercise outside in the heat, says Neil Maxwell, an environmental physiologist at the University of Brighton, in Britain. “That will naturally acclimatise you.” Even better is to add a hot bath. A study published in 2016, in the Scandinavian Journal of Medicine & Science in Sports, found that 40 minutes on a treadmill in 18°C heat followed by 40 minutes in a hot bath, daily for six days, improved several measures of acclimatisation. In fact, as work published in April in Healthcare found, hot baths alone can do the trick. This research, which looked at healthy adults aged over 65, showed that an hour a day in a 40°C bath produced signs of acclimatisation after just four days. So there is, as it were, no need to sweat it. Simply immersing yourself in hot water brings about the necessary increase in core temperature, says Laura Wilson of Middlesex University, also in Britain, who led the study. Acclimatisation is not permanent. “If you don’t keep exposing yourself to heat, then you’re going to start losing the adaptive benefits,” says Dr Maxwell. Still, only a few days of training are needed in the lead-up to a
heatwave. The evidence suggests 75-80% of adaptations build up in the first four to seven days. Heat can be dangerous. And acclimatisation is not immunity. The usual risks from heat still apply. “Try and replace 150% of the fluid you lose during any kind of session to acclimatise,” says Dr Wilson. “If you’re starting to feel faint or dizzy or lightheaded, take yourself out of the environment.” When done safely, however, some simple tactics could help take the edge off the weather. Jumping in a hot bath may not be appealing as temperatures begin to rise. But your future self will thank you for it. ■ After a free, evidence-based guide to health and wellness? Sign up to our weekly Well Informed newsletter. This article was downloaded by zlibrary from https://www.economist.com//science-and-technology/2026/07/10/how-to-train-for-a- heatwave
A very silly adaptation of “The Odyssey” Why Sir Christopher Nolan inspires such devotion—and contempt Emo culture was not just a phase, as it turns out A mystery street artist is taking over cities George Sand’s life was a heady mix of sex and serious fiction The wild, gripping story of the Nord Stream pipeline bombing