In April 2024, a study conducted by researchers from the Australian National University painted a worrying picture of the future. The findings revealed that Australia could soon experience megadroughts lasting over 20 years. Months later, in January 2025, Los Angeles was swallowed in flames, rapidly linked to the severe drought conditions sweeping around the country. As the planet gets warmer, disasters such as megadroughts are likely to become more frequent. 

According to the World Economic Forum, megadroughts are a “period of unusually dry weather—typically caused by a lack of rainfall—that has damaging consequences such as damaging crops and causing water shortages.” It can last for decades and immensely affect the ecosystem and biodiversity of the area.

Megadroughts are persistent, multi-year drought events. They are extreme in terms of severity, duration, or spatial extent compared to other droughts of the last two thousand years, according to a 2022 study published in the journal Nature Reviews Earth and Environment. In the past, megadroughts were primarily caused by persistent variations in the sea surface temperatures. However, climate change has reportedly intensified ongoing droughts. It also increases future megadrought risk through the decline in “precipitation and widespread increases in evaporative demand,” the study revealed.

Since 1980, multi-year megadroughts have become increasingly common, and now a new study, published in the journal Science, warns that they will become more frequent, severe and extensive.

In a press release, they revealed that every year since 1980, drought-stricken areas have spread by an additional fifty thousand square kilometres on average—the size of Slovakia— “causing enormous damage to ecosystems, agriculture, and energy production.”

Image credit: Unsplash, photo by Pawel Czerwinski

Chile is a devastating example and has been experiencing a prolonged megadrought since 2010, impacting its water sources. It’s the longest drought in Chile in a thousand years. The megadrought has not only affected precipitation and temperatures, but also lakes and glaciers. According to a 2023 study, Impacts of the Major Drought in Chile and Mitigation Measures, between 2010 and 2020, the mountain lakes of central Chile, once the primary source of pure water, dried up. In Chile, grass has become a rare occurrence, pollination is severely disrupted and “browning” of vegetation is now common and irreversible, the study reveals.

In the 2025 study, Global increase in the occurrence and impact of multiyear droughts, researchers found that megadroughts had the highest immediate impact on temperate grasslands. The regions identified as ‘hotspots’ for megadroughts include the western USA, central and eastern Mongolia, and particularly southeastern Australia. 

This study also highlighted that current mitigation strategies mostly treat droughts as yearly or seasonal events. However, the world is facing longer and more severe megadroughts that will emerge as major disasters. The researchers call for more realistic preparation and prevention measures.