Megadrought alert: Climate change driving extreme dryness

Megadroughts, more accurately referred to by scientists as multi-year droughts, have a significantly negative impact on ecosystems. Scientists have shown that such events are becoming increasingly dry and hot, leading to a significant decline in vegetation, increased tree mortality, and disruptions in the water cycle.

In the latest edition of the weekly "Science", scientists from Austria, Switzerland, and Singapore warn that since 1980, multi-year droughts are becoming longer and more intense each year. In total, they examined over 13,000 multi-year droughts worldwide, including droughts in the western regions of the United States and the ongoing drought in Chile since 2010.

They believe that global warming, which has accelerated over the past 50 years, is the primary factor contributing to the increased intensity of megadroughts. Areas covered by steppe vegetation are particularly threatened by desertification.

Climate models predict that by the mid-21st century, conditions may worsen, and average vapour pressure deficits in the southwestern United States could be comparable to the worst droughts in history. Changes in average hydroclimatic conditions, not just their variability, determine the risk of megadroughts in this region.

As described by researchers in "Science," historical multi-year droughts had serious environmental and socio-economic consequences, contributing to the collapse of complex societies such as the Khmer Empire or the Maya. Contemporary megadroughts, intensified by greenhouse gas emissions, can lead to similar challenges, affecting water availability, agriculture, and ecosystem health.

Authorities in California announced on Wednesday that since January 7, 28 people have died during fires on the west coast of the United States. The elements continue to devastate this region, and the threat is so serious that now evacuations must be conducted for residents of areas near San Diego. The raging element results from a complex combination of events. Strong Santa Ana winds have been fanning the fires, and dense construction in traditionally fire-prone areas exacerbates the problem.

Added to this are the effects of climate change and drought. Under normal conditions, this region experiences rain and snow in the winter, but last winter was exceptionally dry. Throughout the year, the Los Angeles area received very little rain. The lack of rain results not only in shortages of drinking water, necessary for agriculture among other things, but also increases fire risk. Climatologists have been warning for nearly a decade that California is experiencing a drought on a scale not seen in over a thousand years.

In light of these forecasts, it is necessary to take actions to mitigate climate change and adapt to new environmental conditions. Reducing greenhouse gas emissions and sustainably managing water resources can help reduce the risk and impacts of future megadroughts.

Studies related to "Science" are consistent with the UN report on Earth's drying problem. The UN report indicated that more than three-quarters of the land surface is experiencing drought, although some ecosystems – covering just over one-fifth of the land area – have received more water.