If you’ve spent any time in Spain over the last five years, you’ve probably noticed the weather becoming increasingly unpredictable. Summers seem hotter than ever, heatwaves are lasting longer, wildfires are becoming more destructive, and when it finally rains, it often arrives in torrential downpours rather than gentle showers.

At first glance, it seems natural to blame climate change alone. However, scientists are increasingly pointing to another factor that may be helping to accelerate the warming we are experiencing across Spain and southern Europe: cleaner air.

That sounds completely backwards. Surely reducing pollution should make the planet cooler?

The answer is both yes and no.

For decades, pollution from power stations, factories, shipping and vehicles released tiny particles known as aerosols into the atmosphere. Unlike carbon dioxide, which traps heat, these particles actually reflected some of the Sun’s energy back into space. They also made clouds brighter and more reflective, reducing the amount of solar energy reaching the Earth’s surface.

In effect, air pollution acted like a thin sunshade.

Over the last twenty years, Europe has dramatically cleaned up its air. Spain has reduced sulphur emissions, vehicle exhaust pollution has fallen thanks to stricter emissions standards, cleaner fuels have been introduced, and even international shipping has been required to use much lower sulphur fuels.

These changes have been hugely beneficial for public health. Cleaner air means fewer respiratory illnesses, fewer heart attacks and longer life expectancy.

However, by removing these cooling aerosols, scientists believe we have also removed part of the natural “mask” that had been hiding some of the warming caused by greenhouse gases.

The carbon dioxide is still there, but now more sunlight reaches the ground.

Spain is particularly vulnerable because of its location in the Mediterranean basin, one of the world’s recognised climate change hotspots.

Since 2022, Spain has experienced some of its hottest years on record. Temperatures above 45°C have become increasingly common in parts of Andalusia and Extremadura, while nights that fail to cool below 25°C have become more frequent across much of the country.

The consequences have been obvious.

Wildfires have become larger, more intense and harder to control. Regions including Valencia, Catalonia, Castilla y León and the Canary Islands have all suffered devastating fires during recent summers. Longer heatwaves dry out forests and vegetation, creating perfect conditions for fires to spread rapidly.

At the same time, warmer air can hold significantly more moisture.

That may sound surprising during a drought, but when weather systems do develop, they often produce much heavier rainfall.

Spain has witnessed this repeatedly in recent years. Powerful DANA weather systems have brought catastrophic flash flooding to parts of the country, with roads becoming rivers, homes inundated and entire communities cut off. Eastern Spain, including the Valencia region, has experienced several of these extreme rainfall events, demonstrating how a warmer atmosphere can swing between prolonged dry spells and sudden, destructive downpours.

Scientists stress that cleaner air is not causing climate change. Instead, it is allowing more of the warming already created by greenhouse gases to be felt.

Think of it like removing a pair of sunglasses on a bright summer’s day. The Sun hasn’t become stronger—you’ve simply removed something that was reducing its effect.

That doesn’t mean we should go back to polluting the atmosphere.

The health benefits of cleaner air are enormous, saving millions of lives worldwide. The real challenge is that while we have successfully reduced pollution that temporarily cooled the planet, we have not reduced carbon dioxide emissions quickly enough.

For Spain, the future is likely to bring more frequent heatwaves, longer wildfire seasons and an increased risk of intense rainfall events unless greenhouse gas emissions continue to fall globally.

Cleaner air is undoubtedly something to celebrate, but it also reminds us that the true driver of long-term warming remains the build-up of greenhouse gases in our atmosphere. As the pollution haze disappears, Spain is increasingly feeling the full force of a warming climate.