Natural climate variability (including the El Niño phenomenon) can result in extreme weather and climate impacts, but climate change is leading to changes in the frequency, intensity, spatial extent, duration and timing of weather and climate extremes. Sometimes these impacts can be unprecedented.
Climate change is already affecting every inhabited region across the globe, with human influence contributing to many observed changes in weather and climate extremes (IPCC AR6-SPM).
For example, as air warms it can hold more water vapour – about 7% per 1 °C – increasing the intensity of heavy rainfall events.
More frequent and more intense weather events, such as severe heatwaves, and heavy precipitation lead to increased impacts on more vulnerable populations.
Additionally, human influence has likely increased the chance of compound extreme events since the 1950s, including increases in the frequency of concurrent heatwaves and droughts.
The number of disasters has increased by a factor of five over the past 50 years, driven by climate change, more extreme weather and improved reporting. Improved early warnings and disaster management, has decreased the number of deaths almost three-fold.
Extreme weather events have increased to the point that World Meteorological Day 2022’s theme was Early Warning and Early Action and focused strongly on climate change and extreme weather.
Improving the understanding and characterization of extreme weather and climate impacts is also crucial for decision support and Disaster Risk Reduction (DRR).