A new study by Swiss and Austrian scientists has found that persistent multi-year droughts have become increasingly common since 1980 and will continue to proliferate as the climate warms.
There are multiple examples in recent years in places ranging from California to Mongolia to Australia. Fifteen years of persistent megadrought in Chile have nearly dried out the country’s water reserves and even affected Chile’s vital mining output. These multi-year droughts have triggered acute water crises in vulnerable regions around the world.
Droughts tend to only be noticed when they damage agriculture or visibly affect forests. An issue explored by the new study is whether megadroughts can be consistently identified and their impact on ecosystems understood.
The researchers analyzed global meteorological data and modeled droughts over a forty-year period beginning in 1980. They found that multi-year droughts have become longer, more frequent, and more extreme, covering more land. Every year since 1980, drought-stricken areas have spread by an additional fifty thousand square kilometers on average, an area the size of Vermont and New Hampshire combined.
The trend of intensifying megadroughts is clearly leading to drier and browner ecosystems. Tropical forests can offset the effects of drought as long as they have enough water reserves. However, the long-term effects on the planet and its ecosystems remain largely unknown. Ultimately, long-term extreme water shortages will result in trees in tropical and boreal regions dying, causing long-term and possibly irreversible damage to these ecosystems.
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Photo, posted January 7, 2018, courtesy of Kathleen via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio
