The 2010 Amazon Drought

node · earth · Amazon Basin, extensive

A second severe drought five years after the first, and more extensive. Lewis and colleagues reported in 2011 that the area of forest experiencing drought in 2010 exceeded that of 2005, and that the committed biomass carbon loss was correspondingly larger. Its drivers were compound rather than singular: an El Nino early in the year followed by record warmth in the tropical North Atlantic later in it, so the basin received two separate suppressions of rainfall in one calendar year. The Rio Negro at Manaus fell to a record low that October, on the gauge series that had by then been running for more than a century. What made 2010 change the conversation was not its severity but its timing. A once-in-a-century drought that recurs within five years is not a once-in-a-century drought, and the possibility that the return interval itself was shortening moved from speculation to a measurable question.