Europe suffered unprecedented wildfires and heatwaves in 2025, impacts that are expected to worsen on the world’s fastest-warming continent.

Last year was the hottest year on record in the UK, Iceland and Norway and one of the three hottest years in Europe as a whole, according to an annual report by the European Centre for Medium-Range Weather Forecasts (ECMWF). More than 95 per cent of the continent experienced above-average annual temperatures. Scandinavia, Finland and north-western Russia saw their worst-ever heatwave, 21 days of simmering temperatures that reached 30°C (86°F) even at the Arctic circle.

This extreme heat probably stunted animal and plant growth while encouraging the spread of invasive species and pests, showing how the climate crisis is contributing to a crash in biodiversity, at the World Meteorological Organization said at a press conference.

“This region would [typically] see zero to two days of strong heat stress, and we are speaking about 21, so this had a major impact on ecosystem health,” she said. “Since 1980, Europe has been warming twice as fast as the global average, [and] heatwaves are becoming more frequent and severe.”

Climate warming set the stage for record wildfires in Portugal and Spain in August, the extremely hot, dry, windy conditions there at least 40 times more likely. More than 10,000 square kilometres burned, and at least three people were killed. Fires approached Madrid, and authorities had to shut down parts of the Camino de Santiago pilgrimage route. Smoke drifted as far as the UK.

Across Europe, wildfires emitted 47 million tonnes of carbon, a record amount. Spain, the UK, the Netherlands, Germany and Cyprus all topped their previous fire-emissions records.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

Soil conditions were the driest in 33 years of observations, with more than a third of Europe suffering extreme agricultural drought, especially the UK, Turkey and Ukraine. While parched soils probably encouraged wildfires in many countries, it was increasing fluctuations in the weather that supercharged the blazes in Portugal and Spain, according to at ECMWF. An extremely wet spring that boosted vegetation growth was followed by record summer heat, which dried out those plants and shrubs, creating a tinderbox.

“If you have a very high fuel load in addition to the wildfire weather, so hot, dry winds in particular, that’s when we get these catastrophic conditions where wildfires spread very quickly,” Burgess said at the briefing. “National parks need… firebreaks around them to make sure if there is a fire, it doesn’t spread.”

The ocean around Europe was also abnormally hot, breaking the record for annual sea surface temperature for the fourth year in a row. A record 86 per cent of these seas suffered strong, severe or extreme marine heatwaves. The most extreme hotspots occurred west of Ireland, south of Iceland and south-east of Spain.

For the past three years, heatwaves have struck 100 per cent of the Mediterranean Sea, which is warming up faster than the global average. Waters in Italy and Spain reached 30°C, warmer than a typical swimming pool, raising the risk of fish death, as well as the spread of bacteria and algae. Past marine heatwaves in the Mediterranean have killed off huge amounts of coral, seagrass beds and shellfish.

To limit future damage, Europe needs to lead the way on slowing climate change, of the European Commission said at the briefing. In 2025, solar power generated a record 12.5 per cent of the continent’s electricity, with a total 46 per cent coming from renewables.

European countries are also among those taking part in the first in Colombia this week, which was organised after the COP30 climate summit in Brazil failed to agree on a roadmap to end oil, gas and coal emissions.

At the same time, Europe should adapt to future climate risks, such as multi-year megadroughts similar to the one already gripping the western US, according to officials.

“We need to address these risks,” Chrenek said. “The cost of inaction is significantly higher than the cost of tackling negative impacts.”

A battery made of iron and salt could provide emergency power – without the threat of fire – near one of California’s oldest redwood forests.

The 200-kilowatt battery will be paired with solar panels at the Alliance Redwoods Conference Grounds in Sonoma County, California. This facility is in a high wildfire risk zone in a redwood forest, and it’s only 16 kilometres from the Armstrong Redwoods State Natural Reserve, home to some of the state’s tallest and oldest trees. During extreme weather and wildfires, firefighters and evacuees rely on the conference site, but it’s also vulnerable to electricity grid outages.

“The way we looked at the technology is, how could we make a safe, abundant, low-cost energy storage system,” says at Inlyte Energy in California. “And that led us to very large cells with a very cheap and abundant active material, iron and salt.”

The battery project could deliver up to two weeks of emergency backup power once it becomes operational in 2027. That could keep the lights on in the conference grounds and also supply energy to a firefighting water pump station nearby, without putting the iconic redwoods at risk.

That is because these easily-sourced battery materials – powdered iron and salt contained in a ceramic tube – are also non-flammable. “We can put these batteries and battery cells quite close together without any sort of fire and explosion risk, which is a main issue with packing tons of lithium-ion batteries close together,” says Kaun.

The lithium-ion batteries in smartphones or electric cars sometimes catch fire, and this risk can be magnified when many batteries are clustered together in large energy storage plants. In January 2025, for example, a fire at the world’s largest battery storage facility in California destroyed 300 megawatts of energy storage. By comparison, Inlyte’s iron-salt batteries could store energy with much lower risk. The iron-salt battery project received just over $4 million in from the US Department of Energy to improve energy resilience in the wildfire-prone region near the redwood forest.

Free newsletter

Sign up to The Weekly

Sign up to newsletter

“These non-flammable batteries seem like a smart choice for project developers looking to put energy storage systems in any remote or arid places or near forests subject to periodic drought,” says at San José State University in California. “Energy technologies and infrastructure have a long history of starting wildfires, and non-flammable batteries offer a way to avoid some of that risk.”

Fast-moving wildfires in the Los Angeles area are burning out of control long after fire season normally ends in California. Powerful Santa Ana winds are not unusual for this time of year but they have arrived after months of drought. The combination has led to a disastrous series of fires, in a possible indication of how climate change is shifting the way fires behave in the state.

“While Santa Ana fires are nothing new in southern California, this type of explosive fire event has never happened in January before, and it’s only happened once in December,” says at the University of California, Merced.

As of 8 January, at least four wildfires were burning in the Los Angeles area, . The two largest fires are the Palisades fire and the Eaton fire, which have each burned more than 4000 hectares (10,000 acres) in a day. The fires have killed at least two people and destroyed at least a thousand homes, as well as forcing tens of thousands of people to evacuate. The fires have also threatened NASA’s Jet Propulsion Laboratory and the Getty Museum.

Monster wildfires are sending more smoke into the stratosphere

Smoke lofted into the upper atmosphere on towering pyrocumulonimbus clouds can spread around the globe and affect the climate

The strong Santa Ana winds have reached speeds of up to 129 kilometres (80 miles) per hour, fanning the flames and driving their rapid spread. The windstorm is expected to be the most intense one since 2011, with “extremely critical fire weather conditions” the afternoon of 8 January, according to the US National Weather Service. Fire weather could continue as late as 10 January, challenging firefighting efforts.

This is the latest in a “very highly improbable sequence of extreme climate and weather events” that have contributed to the intense fires, says at the University of California, Los Angeles (UCLA). The Santa Anas are a regular feature of southern California weather, but wet fall and winter weather usually limits their influence on fires. This year, that rainy weather still hasn’t arrived, leaving vegetation dried out and ready to burn. Plus, there is more vegetation as fuel thanks to a wet winter in 2023 that boosted growth. Intense heat and drought throughout 2024 dried it out.

The combination of lots of fine fuel, drought and strong, hot, dry winds makes for “the most explosive fire behaviour imaginable”, says Kolden.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

Officials are still investigating what ignited the blazes. Understanding the role climate change may have played will also take some time. However, there is reason to think it has made the fires worse.

Above-average sea surface temperatures in the Pacific Ocean, probably driven in part by climate change, have also contributed to the dry conditions. According to at UCLA, these that has blocked wet weather carried on the jet stream from reaching southern California.

The region has seen this kind of high-pressure weather system occur more frequently over the past fifty years, which may be a symptom of climate change, says at the University of California, San Diego.