As the UK has baked through extreme heatwaves this summer, the same question has echoed across television studios and radio interviews: “Was this heatwave caused by climate change?”
It’s the wrong question.
Heatwaves have always happened. They are a natural part of our weather, driven by persistent high-pressure systems. Climate change did not create the June 2026 heatwave any more than it created the famous summer of 1976.
The question is not whether climate change caused the heatwave, but how much hotter and more dangerous heatwaves have become because greenhouse gases, primarily from burning fossil fuels, have accumulated in the atmosphere.
This is the focus of attribution science, which analyses how much hotter a heatwave has become because of these extra greenhouse gases in the atmosphere. It has transformed how climate scientists understand extreme weather. Now our public conversation needs to catch up.
The missing words in the climate conversation are not human-caused climate change, but fossil fuel emissions.
Every heatwave today develops in a warmer atmosphere containing far more greenhouse gases than it did a century ago. This makes every heatwave today hotter than it would have been without those additional emissions.
Our research illustrates this vividly. When we recreated the atmospheric conditions of the 1976 UK heatwave under today’s climate, peak temperatures were around 3-4°C higher. The weather pattern was the same; the climate in which it occurred had changed.
Climate change does not create heatwaves. It loads the dice. Weather variability still determines whether a heatwave occurs, but greenhouse gases released from burning fossil fuels make heatwaves hotter, more likely to break records, and more damaging, to health and infrastructure alike. The same principle applies to heavy rainfall, drought and coastal flooding.
The physics is remarkably simple. The atmosphere doesn’t care about politics. It responds to the concentration of greenhouse gases. Every tonne of carbon dioxide released by burning coal, oil and gas adds to that concentration and shifts the odds towards more damaging extreme weather.
Yet this is rarely how we talk about climate change.
Scientists and journalists often use the phrase “human-caused climate change”. It is scientifically correct, but it describes the consequence rather than the mechanism. It can also make people think first about their own behaviour: the flight they took last summer, whether they recycled or should drive less.
Individual choices matter. But they are not where the story begins.
The story begins with fossil fuels.
Burning fossil fuels accounts for around three-quarters of global greenhouse gas emissions and almost 90% of carbon dioxide emissions. Their cumulative emissions have altered the Earth’s energy balance and changed the climate in which every weather event now unfolds.
One reason this simple physical story became blurred was the success of the personal carbon footprint. Popularised by BP’s “Beyond Petroleum” campaign in the early 2000s, it encouraged people to focus on their own emissions.
This is not about absolving individuals of responsibility. Personal choices and actions are part of the solution. But this campaign shifted public attention away from the much larger challenge of transforming the fossil-fuel energy systems responsible for most greenhouse gas emissions. No amount of shorter showers or diligent recycling can substitute for decarbonising electricity, transport, industry and domestic heating.
So, rather than asking whether climate change caused a heatwave, we should be explaining that greenhouse gases released by burning fossil fuels are accumulating in the atmosphere, trapping heat and amplifying extreme weather. This makes all heatwaves hotter, more likely and more dangerous. Heatwaves will continue to get hotter until these fossil fuel emissions stop accumulating.
The record-breaking European heatwaves and wildfires of 2026 show us that climate change is no longer a distant threat. It is shaping the weather outside our windows today. The atmosphere will continue to respond to greenhouse gas concentrations, regardless of politics or public debate.
The climate we live in today is the least extreme climate you will experience in your lifetimes because of ongoing fossil fuel emissions.
The public conversation needs to catch up with the science. If we are serious about limiting future warming, we must rapidly reduce fossil fuel emissions while making our homes, infrastructure and communities more resilient to the climate change that is already here.
