Hotter and Longer Heatwaves
Climate change is making heatwaves more frequent and more intense. Even a small increase in average temperatures can significantly raise the likelihood of extreme heat events. Scientists use computer models to compare real-world scenarios with hypothetical ones without human influence, helping to quantify the impact of climate change on specific events.
For example, the UK's hottest summer on record in 2026 was made 130 times more likely due to climate change. This summer saw five widespread heatwaves, with 40 days of temperatures above 30°C (86°F). Experts warn that as global temperatures continue to rise, such extreme heat events will become even more common.
Heat domes, which trap hot air under high-pressure systems, are also becoming more frequent. Changes in the Arctic, which is warming nearly four times faster than the global average, may be influencing the jet stream, potentially increasing the likelihood of these heat domes.
More Extreme Rainfall
As global temperatures rise, the atmosphere can hold more moisture, leading to heavier rainfall. For every 1°C increase in air temperature, the atmosphere can hold about 7% more moisture. This has led to more intense and frequent rainfall events worldwide.
In the UK, winters from 2016 to 2025 were 13% wetter than those from 1961 to 1990, according to the Met Office. Globally, the IPCC reports that heavy rainfall events have become more frequent and intense due to human activity. For instance, climate change increased extreme rainfall associated with Hurricane Melissa in the Caribbean by 16%.
Longer and More Severe Droughts
Climate change is altering global rainfall patterns, making some regions drier and more prone to drought. While natural weather systems like El Niño can influence droughts, climate change is exacerbating dry conditions by increasing evaporation from the soil during heatwaves.
In Europe, climate-driven heatwaves worsened drought conditions this summer, with four key rivers reaching record low levels. Drought was declared in all of Wales and two-thirds of England, with parts of southern England experiencing the highest category of drought for the first time.
In the Caribbean, climate change made extreme dry conditions 40% more likely in Jamaica and 30% more likely in Puerto Rico, according to the World Weather Attribution group.
More Fuel for Wildfires
Climate change is increasing the likelihood of wildfires by creating drier conditions that provide more fuel for fires to spread. Extreme heat draws moisture out of soils and vegetation, making them more susceptible to burning.
In 2026, fires in Chile and Argentina resulted in 55,000 evacuations, with the area burned being 36% larger due to climate change. In Canada, over 5,000 wildfires burned this summer, with climate change making the conditions for fires to spread twice as likely.
The combined effects of climate change and shifting land use are projected to increase the frequency and intensity of extreme wildfires globally. The UN Environment Programme suggests that the number of the most extreme fires may rise by up to 50% by 2100.
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Source : BBC News - Science