How climate change worsens heatwaves, droughts, wildfires and floods. BBC 14 November 2024 Mark Poynting and Esme Stallard Parts of Spain have again been hit by torrential rain, just two weeks after the flooding that killed more than 220 people. Like other extreme weather events, episodes of heavy rainfall are becoming more common and more intense in many places around the world, driven by climate change.

Here are four ways that rising temperatures are affecting weather extremes......

1. More extreme rain.....For every 1C rise in average temperature, the atmosphere can hold up to around 7% more moisture. With more moisture available, rainfall can become heavier. Scientists use computer models to simulate how individual extreme weather events unfold in two scenarios..... today's world with around 1.2C of human-caused warming.......a hypothetical world without human influence on the climate.. That way, they can estimate how much a particular storm, heatwave or drought was affected by climate change. Between October 2023 and March 2024, the UK experienced the second-wettest such period on record. This level of rainfall was made at least four times as likely by human-caused warming, according to scientists at the World Weather Attribution group (WWA). In September 2024, deadly floods hit much of central Europe, including Poland, the Czech Republic, Romania, Austria and Italy. The intensity of the rainfall over four days in mid-September was made twice as likely by climate change, the WWA says. Climate change is also likely to have played a part in the heavy rainfall seen in Spain in late October and early November. Scientists point to the influence of rising temperatures, although a full study is needed to evaluate exactly how much of an influence climate change had compared with naturally fluctuating weather patterns. Globally, heavy rainfall events have become more frequent and intense over most land regions due to human activity, according to the UN's climate body, the IPCC. It says this pattern will continue with further warming. 

2. Hotter, longer heatwaves.....Even a small increase in average temperatures makes a big difference to heat extremes. As the range of daily temperatures shifts to warmer levels, hotter days become more likely and more intense. In April 2024, temperatures in Mali rose above 48C during an extreme heatwave across the Sahel region of Africa which was linked to increased hospitalisations and deaths. This level of heat would not have been possible without human-caused climate change, according to the WWA. Such temperature spikes will become more common in many places as the world continues to warm.

In the UK, temperatures topped 40C for the first time on record in July 2022, causing extensive disruption. This would have been extremely unlikely without climate change, the WWA said. Heatwaves can happen as a result of heat domes, which are created when an area of high pressure stays over the same area for days or weeks, trapping hot air underneath. 

3. Longer droughts.....Linking climate change with specific individual droughts can be difficult, because there are lots of different factors that affect the availability of water. Natural weather systems, for example, can play a key role, as was the case with drought in southern Africa in early 2024.....read on   https://www.bbc.com/news/science-environment-58073295