麻豆影视

Skip to main content

Global warming was primary cause of unprecedented Amazon drought, study finds

Share
BRASILIA, Brazil -

Human-induced global warming, and not El Ni帽o, was the primary driver of last year's severe drought in the Amazon that sent rivers to record lows, required deliveries of food and drinking water to hundreds of river communities and killed dozens of endangered dolphins, researchers said Wednesday.

Both climate change and El Ni帽o contributed about equally to a reduction in rainfall. But higher global temperatures were the biggest reason for the drought, according to World Weather Attribution, an initiative that brings together climate scientists to rapidly analyze extreme events and their possible connections to climate change.

The drought was agricultural, combining reduced rainfall with hotter conditions that evaporated moisture from plants and soil. It was that heat-driven evaporation that was critical in the drought鈥檚 severity, said study co-author Friederike Otto, a climate scientist at the Imperial College of London.

鈥淲hat is now about a one-in-50-year event would have been much less likely to occur in a 1.2-degree cooler world. If we continue to warm the climate, this combination of low rainfall and high temperatures will become even more frequent,鈥 Otto said at a news conference Wednesday.

The team uses a scientifically accepted method of running computer simulations of weather events as they would have unfolded in a fictional world without global warming, and comparing those results with what really happened.

The drought in the Amazon 鈥 the world's largest rainforest and crucial in storing away carbon dioxide that would otherwise contribute to warming 鈥 came as Earth endured the hottest year on record. The planet is closer than ever to the 1.5 C increase since pre-industrial times that nations had hoped to stay within to avoid the worst consequences of climate change, such as deadly heat, rising seas, flooding and wildfires.

In Brazil's Tef茅 Lake, water temperatures soared to 39.1 C, likely causing the deaths of more than 150 pink and tucuxi river dolphins, two endangered species. Along the Amazon River, people saw their crops wither and fish disappear, and with travel impossible due to low rivers, formed long lines on riverbanks to receive relief supplies. In Manaus, the region麓s largest city, the more than two million residents choked for months on wildfire smoke.

Study co-author Regina Rodrigues, from Federal University of Santa Catarina, said the drought underscored the Amazon's importance in the fight against climate change.

鈥淚f we protect the forest, it will continue to act as the world鈥檚 largest land-based carbon sink,鈥 Rodrigues said in a statement. 鈥淏ut if we allow human-induced emissions and deforestation to push it through the tipping point, it will release large amounts of carbon dioxide, further complicating our fight against climate change.鈥

Luiz Candido, a meteorologist with Brazil's National Institute for Amazon Research, which didn鈥檛 participate in the study, said the findings support the scientific consensus that climate variations in the region have escalated to extreme conditions.

But Candido also argued that interactions among the oceans, the atmosphere, and the forest are complex and it's not possible yet to separate the impacts of natural climate variability from those of human-induced global warming. He also questioned whether the study overestimated plant evaporation, noting that many Amazon plants are much deeper-rooted than crops and were able to retain much of their moisture by reaching damp, deeper layers.

___

The Associated Press鈥 climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP鈥檚 standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org. 

CTVNews.ca Top Stories

Toronto police say they are searching for a suspect who allegedly shot and killed his brother in an argument at a Scarborough housing complex late Saturday night.

Local Spotlight

Cole Haas is more than just an avid fan of the F.W. Johnson Wildcats football team. He's a fixture on the sidelines, a source of encouragement, and a beloved member of the team.

Getting a photograph of a rainbow? Common. Getting a photo of a lightning strike? Rare. Getting a photo of both at the same time? Extremely rare, but it happened to a Manitoba photographer this week.

An anonymous business owner paid off the mortgage for a New Brunswick not-for-profit.

They say a dog is a man鈥檚 best friend. In the case of Darren Cropper, from Bonfield, Ont., his three-year-old Siberian husky and golden retriever mix named Bear literally saved his life.

A growing group of brides and wedding photographers from across the province say they have been taken for tens of thousands of dollars by a Barrie, Ont. wedding photographer.

Paleontologists from the Royal B.C. Museum have uncovered "a trove of extraordinary fossils" high in the mountains of northern B.C., the museum announced Thursday.

The search for a missing ancient 28-year-old chocolate donkey ended with a tragic discovery Wednesday.

The Royal Canadian Mounted Police is celebrating an important milestone in the organization's history: 50 years since the first women joined the force.

It's been a whirlwind of joyful events for a northern Ontario couple who just welcomed a baby into their family and won the $70 million Lotto Max jackpot last month.