Climate change caused drought in the Amazon region

Climate change has fueled the remarkable 2023 drought that dried up major rivers, sparked massive wildfires and threatened the livelihoods of millions of people in the Amazon rainforest, scientists said Wednesday.

Deforestation of the Amazon, the world's largest and most biodiverse rainforest, has reduced rainfall and weakened the ability of trees and soil to retain moisture, researchers found. That made the drought more acute and made the forest less resilient to environmental destruction and events such as wildfires.

The Amazon – the world's largest by volume – and some of its tributaries reached their lowest levels in 120 years of recording last year. One fifth of the world's fresh water flows through the rainforest.

A severe drought would still have occurred if humans had not changed the climate so profoundly. But the burning of fossil fuels gave it a ranking of “exceptional,” the highest category in the U.S. Drought Monitor's rating system, according to the study published by the World Weather Attribution Initiative, an international collaboration of scientists focused on rapid analysis of extreme conditions. weather events.

As global greenhouse gas emissions continue to rise, the world will experience more extreme droughts, says Ben Clarke, author of the study and researcher at the Grantham Research Institute on Climate Change and the Environment at Imperial College London. “We are now in the highest classification, so we have nothing left to classify.”

The study is further evidence that global warming caused by human activity is accelerating the destruction of the world's largest and most biodiverse rainforest. Parts of the Amazon have begun to transform from rainforest that stores large amounts of heat-trapping gases to drier areas where the gases are released into the atmosphere. The result is a double whammy for the global fight to combat climate change and biodiversity loss.

Awareness of the severity of the drought grew after more than 150 river dolphins suffocated in October. The drought cut off thousands of people who live in remote communities and can only travel by boat. And it caused wildfires that made the air some of the most dangerous in the world.

The drought also forced the closure of a large hydroelectric power station Brazil and severely reduced production of others in the region, causing power outages Ecuador And Venezuela. Countries in the region rely heavily on river flows to generate electricity, and some have had to turn to diesel power plants to meet demand.

The group of scientists from Brazil, the Netherlands, Great Britain and the US used it peer-reviewed methods to determine whether and to what extent the drought has been influenced by climate change and the El Niño climate pattern, which is associated with drought in the region.

The El Niño reduced rainfall, scientists discovered. But higher temperatures caused by the burning of fossil fuels made the lack of rain ten times more likely than it would have been in a hypothetical world in which humans had not changed the climate, they said. Global warming has made the dehydration of soil and plants, as well as reduced river discharge, thirty times more likely.

Although the study only covered the drought from June to November last year, dry conditions persisted into the region's rainy season, marking the first time this has happened in such a significant part of the forest.

The rain has brought some relief to major rivers, but many remain below normal levels for this time of year. The drought is expected to end when El Niño subsides, which scientists expect within a few months.

Scientists say governments can soften the impact of future droughts by reducing deforestation, restoring forests and helping communities adapt.

While Brazil and Colombia have recently slowed the rate of deforestation in the Amazon, the forest continues to lose tree cover. It has already shrunk by almost a fifth of its original size.

Fueled by global warming, the drought has hit some of the most pristine parts of the forests, said Regina Rodrigues, a professor at Brazil's University of Santa Catarina and one of the study's authors.

“We need to reduce emissions,” she said. Otherwise, the forest “will not survive climate change.”