National Emergency Briefing: climate extremes

Professor Hayley Fowler from Newcastle University addressed the National Emergency Briefing about extremes of weather. 

She told us that weather extremes have already been hitting the countries of Europe, causing huge damage and loss of life. In 2024 storm Boris caused extreme rainfall in 6 countries in central and Eastern Europe, causing multiple dams to collapse, and 2 billion Euros of damage. In 2021 in Germany floods killed 200 people. The same weather system also triggered flash floods in London. In Valencia in 2024 ¾ of a metre of rain fell in 24 hours, and 220 people died. The UK is not exempt from this happening in the future. 

Increased greenhouse gases in the atmosphere trap more heat, which increases the moisture content of the air, resulting in warmer, wetter winters and hotter, drier summers. By 2050 1 in 4 properties in England, 8 million, will be at risk of flooding. Professor Fowler’s group has determined that UK winter rainfall is up by about 10% since 1980. That means 7.3 billion cubic metres of extra water each winter, or about 3 million Olympic swimming pools. Most worryingly, the trend is around 25 years ahead of global model projections. An event of the scale of storm Boris would be a national disaster requiring years to recover.

Extreme summer heat is also worsening as a result of climate change, and it can kill. In July 2022 the temperature in England hit 40°C for the first time, which was linked to around 3,000 excess deaths. Summer temperatures in Europe are growing faster than anywhere else in the world, and faster than predicted by the current climate models.

Hot dry summers also threaten water security, stretch healthcare systems, and increase the risk of wildfires. Wildfires can occur on heathland, in forests, and on the edges of cities. A fire in 2025 in Dorset was so serious that 17 fire services were called to contain it.

These changes are a consequence of climate change, which is increasing arctic temperatures 4 times faster than the global average,  decreasing the temperature gradient between the arctic and the equator. This weakens the stability of the jet stream, the mid-latitude air current which drives weather systems over the UK, and slows it. The slower jet stream can stall in one place, creating what are called blocking patterns which can persist for days or even weeks, resulting in extended heatwaves, or prolonged precipitation. For example, a blocking pattern in the Northern hemisphere in summer 2021 resulted in extreme heatwaves in North America, floods in Europe and China, and extreme heat and wildfires in Siberia.

Professor Fowler says that the floods which have occurred in Europe could also happen in the UK, there is no physical reason why not. Such a storm could deposit two thirds of a year’s rainfall in a few days, which in London would amount to 35cm of rain over a large area, three times as much as storm Claudia dropped in Monmouth recently. This would be a disaster. Recovery would not take weeks, it would take years.

It’s hard to imagine the effects of such storms but we have to if we are to prepare for them. Flood waters will inundate homes, sweep away cars, and sewers will overflow. Our infrastructure was designed for a climate which we no longer have. For example, we have over 2000 raised reservoirs, which now have a serious and increasing risk of overtopping. 

The global South has been facing extreme weather events for years. In May 2024 temperatures in Pakistan touched 52°C. At these temperatures, if combined with high humidity, a healthy person in the shade can die in a few hours.

Extreme climate also threatens our food supplies. In the UK we import about half of our food and 40% of our energy. Global weather extremes are a direct threat to families in the UK, causing shortages and price spikes.

According to the Climate Change Committee, the UK is not adequately prepared. We are not adapting fast enough. The committee highlights three gaps: weak governance, unclear responsibility, and insufficient funding. Adaptation needs to be embedded into all key government decisions. We are still building infrastructure which is not resilient to today’s climate extremes, let alone tomorrow’s.

We also need to prepare for cascading crises. For example, a storm could knock out power supplies, shutting down pumping stations and leading to water shortages. This happened in storm Arwen. And what would happen if another disaster occurs before we have recovered from the previous one? We risk being in a state of permanent crisis, never being able to catch up.

Every year that we delay investment in resilience and emissions reduction, the window for successful action grows smaller. 

We can imagine a solution. It is sobering to realise that the current climate, with the extremes described above, is the least extreme climate we will ever face. Until we stop burning fossil fuels, extreme weather will get worse.

This means that we also have to adapt, which requires many things. We need to upgrade flood defences, and build better insulated buildings. Adaptation also improves wellbeing. Better insulation means warmer homes and lower bills. Planting trees and making water absorbing parks in cities, as Copenhagen did, cools the city and cleans the air, as well as improving quality of life for residents.

Every pound spent on adaptation saves many pounds that would be spent dealing with crises in the future, and it creates skilled jobs.

To conclude, climate extremes are with us now. We have the science to understand them and the tools to address them. We need the courage to commit to urgent action.

Hayley Fowler is Professor of Climate Change Impacts at Newcastle University and one of the UK’s leading experts on extreme rainfall and flooding. Her research advances understanding of how precipitation extremes are changing in a warming world and develops improved projections to guide climate adaptation.