ROSS CLARK: How claims by climate scientists that 2,700 people were killed by the heatwaves in May and June are hysterical hot air

Published: 01:00, 14 July 2026 | Updated: 02:39, 14 July 2026 Like many people who lived through it, I have found myself thinking back to the scorching summer of 1976 in recent weeks. I remember those long, hot days spent on the beach, drinking lemon squash by the bucketful. But I also remember hearing a radio report later that July claiming the heat was thought to have killed large numbers of people. I was only nine years old, and I don’t remember the details. Looking back, it was almost certainly a report about a 20 per cent rise in deaths recorded by the registrar in Birmingham during the hottest fortnight of that extraordinary summer. The idea unsettled me. Until then, it had never occurred to me that while my friends and I were revelling in the sunshine, soaring temperatures could prove deadly for the elderly and the infirm. Which is why I don’t take the dangers of extreme heat lightly. But I am deeply sceptical of headlines yesterday claiming that 2,700 people were killed by heatwaves in May and June – around 440 a day during a three-day peak last month – and that 40 per cent of deaths can be attributed to climate change. There is an important distinction between the very real increase in deaths that can occur during periods of extreme heat and the kind of scaremongering that now seems to accompany almost every spell of warm, sunny weather. The claim about 2,700 deaths comes from a study by Imperial College, which, it turns out, didn’t count any actual deaths at all. Like many people who lived through it, Ross Clark has found himself thinking back to the scorching summer of 1976 in recent weeks Rather, it was a piece of statistical modelling which tried to estimate the number of deaths which might have occurred during the heatwave, based on the temperatures recorded over the past weeks and patterns of excess mortality seen during previous hot spells. That might all sound very clever, but there is a slight problem: the conclusions don’t match the real-world data. The UK Health Security Agency (UKHSA) records actual deaths for every week of the year and compares them with the number of people who have died in the same week in recent years. If more people have died this year than the average of the past five years, then that difference is labelled ‘excess mortality’. So, what does the real-world data say for this year? In the week ending May 31, which included the first heatwave when a record temperature of 35.1C (95.2F) was reached in west London, the UKHSA reports that it detected ‘no signal of high mortality above the baseline’. In other words, the May heatwave doesn’t appear to have been accompanied by any excess deaths at all. The full data for the June heatwave, when temperatures reached 37C (98.6F), is not available yet. But provisional data for the week ending June 26 suggests that there were 768 fewer deaths – or 7.4 per cent – than would have been expected for that week, based on past data. It must be emphasised that these are provisional figures and the total might yet rise. But it doesn’t look as if there can have been a big spike in deaths during the second heatwave, either. There is another statistic which the scaremongers like to quote: that the heatwave in 2022 – when 40C (104F) was recorded in Britain for the first time – killed more than 3,000 people. That sounds dramatic but, again, it doesn’t stand up to scrutiny. The claim is based on an Office for National Statistics report which measured the number of deaths in England and Wales during five ‘heat periods’ between June and August 2022 when the average temperature (across day and night) exceeded 20C (68F). As a country, we seem to have convinced ourselves that we are heading for a hellish future of climate-wrought destruction, which will leave us wilting in ever more extreme heatwaves It concluded that the total number of deaths during these periods was 3,271 above the five-year average (excluding the pandemic year of 2020). That sounds convincing... until you realise that excess deaths ran well above normal for most of 2022, during both hot and cold periods. Between March and December that year, there were a total of 43,477 excess deaths. This spike in excess deaths – the worst in half a century – has been well reported but never fully explained. Many have pointed out that the year covered a period when hospitals were still recovering from the pandemic, with non-urgent treatments delayed and A&E services still disrupted. Against this background, it is nonsense to blame every one of the excess deaths recorded during the heatwaves on the soaring temperatures alone. Yet the narrative that the 2022 heatwave claimed 3,000 victims is repeated by uncurious activists and politicians. Yes, the Earth is getting warmer, and we are experiencing more heatwaves. But that doesn’t mean a large rise in deaths is inevitable. Over the past half century, we have become better at dealing with hot weather. The need to stay hydrated during hot weather was less appreciated in 1976. Back then, no one kept a water bottle on their desk at my primary school; the only way to get a drink other than at lunchtime was to queue up at the single water fountain in the boys’ toilets. More importantly, more hospitals now have air conditioning and care homes have become better at ensuring residents keep well hydrated – something which elderly people often find difficult as their sense of thirst declines. We could reduce the toll from heatwaves further if more of our homes had air conditioning. Yet, bizarrely, some of the people who preach loudest about the perils of global warming seem determined to stop this happening. Last week, Jan Rosenow, professor of climate and energy at Oxford University, broke ranks with some of his colleagues by writing in a LinkedIn post there is an increasing need to use air-con ‘in places where it is not yet used at scale’, claiming that Europe’s building stock is ‘not designed’ for higher temperatures. Yes, the Earth is getting warmer, and we are experiencing more heatwaves. But that doesn’t mean a large rise in deaths is inevitable  The reaction was extraordinary. One of his counterparts at the University of Sheffield, Fionn Stevenson, accused him of ‘generically promoting air-con, when we know this just heats up our cities even more’ – on the basis that the hot air removed from buildings ends up outside, on the streets. But hot air from air conditioning units disperses quickly into the vastness of the atmosphere – so it doesn’t heat the outdoors like it cools the indoors. Another crucial fact which tends to get lost amid the hysteria over heatwaves is that as well as experiencing higher temperatures, we are also seeing less extreme cold during our winters – a trend which is saving lives. The most comprehensive attempt to measure the effect on mortality from climate change was made by scientists at Monash University in Australia, who looked at mortality data from 43 countries. The study concluded that extreme temperatures kill 5million people globally every year. But crucially, more than 90 per cent of these deaths were caused by extreme cold rather than extreme heat. This is true on every continent, Africa included. Moreover, while the number of heat-related deaths increased by 0.21 per cent during the years 2000 to 2019, the number of cold-related deaths fell by 0.51 per cent. The authors can hardly be dismissed as climate change deniers – indeed, they predicted more heat-related deaths in future. Yet for now, they observed, climate change is resulting in fewer, not more, temperature-related deaths. Not that this is a story you will hear much about amid the doom-mongering over the climate. As a country, we seem to have convinced ourselves that we are heading for a hellish future of climate-wrought destruction, which will leave us wilting in ever more extreme heatwaves. The truth, thankfully, is a lot more nuanced. AJ Odudu suffers another major blow as her ITV show is axed weeks after Celebrity Big Brother 'is shelved due to finances and casting issues'