The 2023-2024 Amazon Drought

node · earth · Amazon Basin, basin-wide

The most severe drought in the basin's instrumental record, running across two dry seasons and driven by an El Nino coinciding with record warmth in the tropical North Atlantic - the two mechanisms that had acted separately in 2005 and 2010 arriving together. The Rio Negro at Manaus fell below its previous record low in October 2023 and lower again in October 2024, on a gauge series more than a century long. River transport failed across large areas, isolating communities that have no roads; and in a tributary lake of the middle Amazon, water temperatures rose far enough to kill river dolphins in numbers, a mass mortality that gave the drought its defining image. An international rapid attribution study concluded that climate change, rather than El Nino, was the dominant driver of the agricultural and ecological drought. If 2005 established that the Amazon's carbon sink was conditional and 2010 established that severe droughts could recur within a few years, 2023 to 2024 established that they could last through more than one wet season - which is the condition under which forest mortality stops being recoverable.