BUENOS AIRES - Lack of rainfall that caused severe drought in Argentina and Uruguay last year was not made more likely by climate change, scientists said. But global warming was a factor in extreme heat experienced in both countries that made the drought worse, they said.
La Nina usually occurs once every three to five years, often alternating with El Nino, which is linked to above-normal sea temperatures. But La Nina conditions have persisted for most of the past three years, and central South America has been drier than normal for most of that time. The work has not yet been peer-reviewed, but the techniques the researchers used have been peer-reviewed in previous studies.
The area also experienced record-setting heat waves last November and December. Extreme heat can make droughts worse by increasing the loss of moisture from soil and plants, said Mr Juan Rivera, a researcher at the Argentine Institute for Snow Research, Glaciology and Environmental Sciences, who worked on the study.