The difference between day and night temperatures – scientists call it ‘the diurnal temperature range’ – in spring is growing, and that is not good news, scientists say. And the trend is confirmed by the European Environment Agency (EEA) and the World Meteorological Organization (WMO).

In the past, nighttime temperatures increased faster than daytime temperatures, so the gap decreased. However, in recent years, the gap has been growing again, especially in spring, and only in parts of Europe. But why?

‘Blanket effect’

Since the 1990s, Europe’s air has become much cleaner. More sunlight reaches the surface during the day, and the ‘blanket effect’ of pollution has disappeared.

On a clear night, it cools down and warms up faster. Clear skies and increased sunshine, therefore, lead to a greater contrast between day and night. And that contrast is increasing.

No positive trend

Due to climate change, the climate zones have shifted somewhat to the north, leading to higher-pressure areas forming more frequently over Belgium. These result in drier and warmer weather. On top of that, cloud cover has decreased, allowing temperatures to rise.

Scientists broadly agree that this is not a positive trend, as our growing season begins much earlier and we experience more frequent droughts. Plants are vulnerable to late frost, the soil is drier in spring, so less moisture is available, and the risk of summer heatwaves increases.

Reducing the use of fossil fuels is very important to combat climate change, but a secondary effect of cleaner air is that we will face greater warming in Europe. Global warming is occurring twice as fast in Europe as in the rest of the world.