Las extreme heat waves that trigger flash droughts are spreading across the planet at an alarming rate. A recent study by researchers from South Korea and Australia, published in Science Advances (March 6, 2025), demonstrates how these compound phenomena —extreme heat followed by drought— increase as the planet warms.
In the 1980s, these episodes affected only 2.5% of the Earth’s surface each year. By 2023, the figure rose to 16.7%, with a decadal average of 7.9%. The authors warn that the acceleration rate is even more concerning: in the last 22 years, the growth rate has been eight times higher than in the previous two decades.
Flash droughts: more damaging than ordinary ones
When heat arrives first, droughts become more intense and sudden. These “flash droughts” occur because warmer air extracts water from the soil more quickly, leaving little preparation time for the population and the agricultural sector.
Climatologist Yong Jun Kim explains that this type of drought is more destructive than traditional ones, as they set in suddenly and amplify the risk of wildfires.
Recent examples
The researchers cite several emblematic episodes:
- 2010 Russian heat wave, which led to devastating fires.
- 2019-2020 Australian fires, fueled by extreme heat and drought.
- 2021 Pacific Northwest heat dome, with temperatures near 50 ºC in Lytton (Canada), followed by fires that destroyed the locality.
- Yangtze River drought in China (2022).
- Record drought in the Amazon (2023-2024).
Most affected regions
The study indicates that the largest increases in heat-triggered droughts are recorded in:
- South America.
- Western Canada and Alaska.
- Western United States.
- Central and Eastern Africa.
The researchers detected a tipping point around the year 2000, coinciding with the rapid warming of the Arctic, the loss of sea ice, and the decline of spring snow in the northern hemisphere.
The role of El Niño
The El Niño phenomenon, which warms parts of the Pacific and alters global climate, also plays a key role. The intense episode of 1997-1998 may have accelerated changes in Earth’s climate and ecological systems. Recent models forecast another strong event towards the end of this year, which could further intensify compound extremes.
The study confirms that climate change not only increases the frequency of heat waves and droughts but also alters the way they interact, generating more severe and sudden risks. The combination of extreme heat, drought, and wildfire risk constitutes a dangerous climate cocktail that threatens food security, public health, and the stability of entire ecosystems.
