France has declared a national emergency as a severe heatwave, with temperatures surpassing 40 degrees Celsius in several regions, forces the closure of schools and the activation of red alert protocols. The UK, meanwhile, is bracing for its own extreme weather event, with forecasts predicting record-breaking temperatures that could strain infrastructure and threaten lives.
The French government’s decision to shutter schools is a stark recognition of the immediate threat posed by heat stress to children, who are physiologically more vulnerable to overheating. The red alert, the highest level in Meteo France’s warning system, triggers a cascade of public health measures: air-conditioned shelters open, public events are cancelled, and hospitals are put on standby. This is a climate event, but it is also a public health crisis, one that underscores the widening gap between our adaptive capacity and the accelerating pace of planetary warming.
The physics here is straightforward. The Earth’s energy budget is out of balance due to increased greenhouse gas concentrations. More energy is trapped in the atmosphere, which amplifies the intensity and frequency of heatwaves. The jet stream, which typically acts as a barrier between hot and cold air masses, is becoming wavier, allowing hot air to stagnate over regions like France. This is not a new phenomenon, but the baseline is shifting. What was once a once-in-a-century event is now a recurring reality.
In the UK, the Met Office has issued its first ever red extreme heat warning for parts of England, with temperatures expected to reach 40 degrees Celsius for the first time. This is a threshold that, just a few years ago, seemed improbable. The UK’s infrastructure, from its rail network to its housing stock, was not designed for such heat. Tracks buckle, concrete expands, and indoor temperatures can become lethal without air conditioning, which remains rare in British homes.
The energy system is also under threat. Higher temperatures reduce the efficiency of thermal power plants and increase demand for cooling, creating a vicious cycle. France, heavily reliant on nuclear power, has faced additional challenges as some plants have been forced to reduce output because cooling water is too warm or scarce. This is a reminder that our energy transition must account for the very climate stresses it seeks to mitigate.
There is a tendency in reporting to focus on the novelty of these events, but the science is clear: this is the predicted outcome of our continued reliance on fossil fuels. The Intergovernmental Panel on Climate Change’s Sixth Assessment Report explicitly states that heatwaves have become more frequent and more intense since the 1950s, and that this trend will continue with further warming. Each fraction of a degree of warming increases the intensity of extreme heat events, making them longer and more dangerous.
The response must be dual: adaptation and mitigation. In the immediate term, we need early warning systems, cooling centres, and public education about heat health risks. In the long term, we must accelerate the transition to renewable energy and implement land-use changes that reduce the urban heat island effect. But these measures are only as effective as the political will behind them. The fact that we are still debating the reality of climate change while schools close in Paris is a tragedy of our own making.
As a climate correspondent, I am often asked whether there is hope. My answer is that hope is irrelevant; what matters is action. The laws of thermodynamics do not care about our sentiments. The planet will continue to warm until we stop adding carbon to the atmosphere. The heatwave in France and the looming one in the UK are not anomalies. They are the new normal, a signal that the biosphere is responding to the pressure we have placed upon it. The only question that remains is how quickly we will adapt and how drastically we will mitigate.
For now, the priority is protecting lives. In France, the emergency will pass, but the threat will not. In the UK, the coming days will test the resilience of a nation unaccustomed to such extremes. The data does not lie: we are in a state of calm urgency, and the time for incremental change is over.