Megadrought in Chile: Both natural climate factors, human-induced global warming to blame
The prolonged drought in central Chile is a result of a combination of climatic factors, both natural and human-induced global warming.
The megadrought — the longest and most intense one in the region in the last millennium — has impacted lakes and glaciers, a report has found. This has led to water scarcity, food insecurity, loss of livelihoods and massively impacted biodiversity.
The report by World Meteorological Organisation, called State of the Climate in Latin America and Caribbean, 2021, was released July 22, 2022. It highlighted the length and strength of the drought, which started in 2010 and is still ongoing. WMO is a specialised agency of the United Nations for meteorology.
Central Chile experienced temperatures above normal (1981-2010) by 1-2°C in 2021. This is higher than the general warming of the continent by 0.36°C, WMO found.
Most of Chile also experienced below-normal rainfall in 2021, a trend that has now held for 13 years. There was a rainfall deficit of 20-60 per cent over different regions of the country.
Some research indicates that the drought began in 2007, which would push the drought period to 16 years.
Between 2010 and 2018, Chile’s rainfall deficit varied from 20-40 per cent.
With further warming of the Earth’s atmosphere and the oceans, the sea level pressure will further get enhanced and cause even more frequent and intense megadroughts in the decades to come.
Coquimbo and Araucania received 30 per cent less rain than average from 2010-2015, according to a report published by Centre for Climate and Resilience Research (CR2) in November 2015. CR2 is a research centre based in Chile.
The WMO report has further found that Chile’s Dry Andes and Central Andes glaciers lost 0.72 and 0.56 metres water equivalent (m we), respectively, in 2021. One m we is equivalent to around 1.1 metres loss in glacial ice thickness.
The mountain lakes in central Chile, a major source of freshwater, also dried up between 2010 and 2020. There was a surface area reduction in the same period in 12 lakes from 7 per cent to 25 per cent, according to a research paper published in the Journal of Hydrology: Regional Studies in December 2021.
“The continuing drought (in Chile) and loss of surface and underground water resources severely affected dozens of rural communities, requiring water to be supplied by trucks,” WMO said in a StoryMap on its website.
The situation is also dire in urban areas. In April 2022, the Government of Chile announced an unprecedented water rationing plan for its capital city Santiago.
