A mass of warm water in the south of the Pacific located east of New Zealand could be behind the mega-drought that Chile has suffered for more than a decade, as it could generate the hot and dry conditions that caused the melting of the ice caps of snow in the Andes, the depletion of reservoirs, and the degradation of landscapes.
According to an investigation published in the Journal of Climate, climate change caused by man is partly to blame for this mass of hot water and, consequently, for the drought. The role it has played, however, is still unclear as the natural variability of oceanic and atmospheric temperatures also played a part in this issue, the scientist stated.
The huge mass of hot water is wider than the continental United States and it is now 1.5 degrees Celsius warmer than 40 years ago. Its heat increases the air temperature directly above it and the winds carry the hot air towards Chile. This influences pressure trends, affecting rainfall and causing dry conditions in the South American country.
The water mass is perhaps only 3% of the South Pacific, but it is located in an area so sensitive that it produces this chain of events, stated the co-author of the study, Rene Dario Garreaud, a climate scientist from the University of Chile in Santiago.
Ocean patches also occur regularly and dissipate within a couple of years. However, the researchers found that the prolonged and pronounced rate of warming of the southern ocean patch goes beyond what could occur naturally.
"We know the patch is natural, but it is reinforced by climate change: climate change is the reason why it has lasted so long and it's so intense," said Garreaud.
Scientists who did not participate in the work have already expressed concern about the results of the study.
"I find it very worrying to see that man-made climate change is amplifying the severity of mega-droughts," said Andreas Prein, a climate scientist at the National Center for Atmospheric Research in the United States. "These types of (extreme) droughts are responsible for the collapse of historical civilizations, such as the Mayans or the Ming dynasty, and can destabilize modern cultures."
The fact that a strip of warm water, even one that spans more than 8 million kilometers, can affect conditions thousands of kilometers away in Chile shows the extent to which climate change will affect the planet, stated Dillon Amaya, a scientist from the University of Colorado at Boulder.