Climate change blamed for extreme weather in Brazil

Climate change blamed for extreme weather in Brazil
Climate change blamed for extreme weather in Brazil

About 150 people have died or gone missing after recent record heavy rains that have caused flooding and landslides in three Brazilian states.

Scientists say global warming is contributing to more extreme weather events in the country, and warn that such natural disasters could become the "new normal."

The annual monsoon rains in Brazil are rarely fatal. Floodwater floods the streets, and landslides affect poor communities and favelas built on steep hillsides, often without adequate drainage and sanitation.

Global temperatures, which have risen sharply since 1980, are causing more evaporation and more rainfall.

Official figures from The Guardian indicate that "extreme rainfall" (where more than 80 mm or 100 mm falls within 24 hours) has increased dramatically over the past 30 years in the capitals of the southeastern states of São Paulo, Rio de -Janeiro and Belo Horizonte, where the deadly rains fell.

Scientists blame this on a combination of urban growth and climate change.

“We are seeing more and more extreme weather events occurring in large cities and there is a clear link to higher average global temperatures,” says Terzio Ambrizzi, professor of climatology at the University of São Paulo.

Guaruja, a coastal town 25 miles from São Paulo, received 282mm of rain in just 12 hours last week - more than expected for all of March.

“I've never seen it raining like this,” says Rafael Soares, 22, who was hit by a landslide on March 3 that killed 18 people and dozens are still missing.

Soares heard a deafening rumble around 1 am and ran up the hill behind his house, where he discovered that part of his community had been buried under a layer of mud.

“Older people talk about floods in the 1970s, but nothing about floods of this magnitude,” says Bruna Aguiar, an activist with Favela Fari Akari.

According to the Brazilian National Institute of Meteorology (Inmet), the weather station in Rio de Janeiro recorded 134 extreme showers between 1960 and 1990 and 221 between 1990 and 2020. The Sao Paulo Weather Station reported 15 from 1960 to 1990 and 44 from 1990 to 2020.

“It is clear that extreme events are on the rise in southeastern Brazil,” Ambrizzi says.

Scientists argue that "urban heat islands" created by concrete and lack of vegetation in large cities increase temperatures, and the lack of permeable soil leads to large floods. Global warming only amplifies the effect.

True, not all scientists believe global warming is responsible for this weather. The Brazilian Space Research Institute believes that the rains were "a meteorological phenomenon typical of the summer."

In January, 59 people died in torrential rains in the state of Minas Gerais. According to Inmet, its capital, Belo Horizonte, experienced 30 “extreme rains” from 1960 to 1990 and 52 from 1990 to 2020.

In Belo Horizonte, 13 people died in January when one weather station recorded 935 mm of rainfall - the highest level since 1910 and more than half the annual rate.

Heavy rains and subsequent droughts are likely to continue, according to Carlos Nobre, one of the leading climate scientists and senior research fellow at the Institute for Advanced Study at the University of São Paulo. “This is the new norm,” he said.

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