40°C in June Must Be a Wake-Up Call on Climate Change, Scientists Say

Scientists are warning that UK leaders are not taking the climate crisis seriously enough after weather forecasters said temperatures could reach 40°C in June — only the second time that has ever happened since records began. The Met Office issued rare red warnings for extreme heat, and experts say the predicted temperatures are "incredibly alarming." If the record is broken, it would smash the previous June record set back in 1976 by several degrees. Scientists say the extreme heat is caused by human-driven climate change and is a danger to people's health.

Professor Friederike Otto of Imperial College London pointed out that the UK already hit 40°C in 2022, and warned that people in power did not do enough after that event. "Our first 40°C day was supposed to be a wake-up call, but clearly someone hit snooze," she said. She added that hitting 40°C again — and in June this time — would be "incredibly alarming." She said scientists have been giving the same warnings for years, and that the root cause is clear: human activity driving climate change, not natural events like El Niño.

Professor Otto also highlighted the real harm the heat is causing to everyday people right now. Children are struggling to finish their exams in sweltering, or extremely hot, classrooms. Elderly people are stuck in dangerously hot homes and care facilities with little relief. She was clear that this is not just an uncomfortable situation — it is a serious and growing threat to public health that puts lives at risk every time a heatwave strikes.

The extreme heat is being caused by a "heat dome," a system where hot air gets trapped over a region, sitting over western Europe and being made worse by climate change. These high temperatures are creating problems for health services, schools, workers, and transportation across the UK. The heatwave is happening at the same time as London Climate Action Week, a gathering of people working on climate issues. Organizers at the event are sending out heat warnings and bringing in extra air conditioning units, while encouraging everyone to drink plenty of water.

Some historic buildings, like Mansion House — the official home of the Lord Mayor of London, built in the 1740s — have upgraded their cooling systems to handle the heat. But experts say there is only so much that can be done. The UK's buildings and infrastructure, meaning its roads, railways, and power systems, were simply not designed for this level of extreme heat. A major report from the government's Climate Change Committee warned last month that the country is not doing nearly enough to prepare for the worsening climate crisis.

That report included some striking findings. More than nine out of ten homes in the UK are not well insulated enough to keep the heat out. By 2050, the country could face a daily shortage of five billion litres of water. These numbers show that climate change is not just a future problem — it is already affecting how people live today, and the gap between what is needed and what is being done is growing.

Professor Bill McGuire of University College London warned that temperatures above 43°C are now possible in the UK, with heatwaves lasting several days. He painted a worrying picture of what that could mean: people sleeping in the streets because their homes become too hot to live in, power cuts as electricity cables overheat and fail, and chaos on public transport as rails and signals break down. He also warned that hospitals and emergency services could be overwhelmed trying to care for elderly people, young children, and others made seriously ill by the heat.

Professor Richard Allan of the University of Reading said the current situation is proof that the global warming scientists warned about decades ago is now actually happening. He noted that a warmer atmosphere holds more moisture, which does not just mean more heat — it also means more intense droughts and heavier rainfall that can lead to flooding. He said the solution is the same as it has always been: reducing greenhouse gas emissions across every part of society, from industry and transport to farming, while also making changes to adapt to the new climate realities the world is already facing.