Chain reaction in the Amazon

Deforestation in world's largest rainforest linked to extreme climate events, say experts

BRASILIA • Tiny Camargo, a municipality in Brazil's Rio Grande do Sul state which has about 3,000 inhabitants, has been facing one crisis after another.

In February last year, five days after declaring a state of emergency due to drought, the municipality was struck by heavy rain which unroofed 70 houses. Then another state of emergency was declared, for different reasons - this time, due to heavy wind.

News of natural disasters have been commonplace to many people living in Rio Grande do Sul and officials estimate billion-real (real is the Brazilian currency) losses due to extreme climate events in the state, reports Zero Hora newspaper.

The most recurring among those events is drought, which has struck the state hard in the last two years. Civil defence estimates losses in the 107 municipalities in the state to be 2.6 billion Brazilian real (S$659 million) for the year 2020-21.

Climatologists believe that extreme situations would become even more commonplace in the following years, with many linking the phenomenon to deforestation in the Amazon.

Between August last year and July this year, the rainforest lost 10,476 sq km - an area nearly seven times bigger than Greater London - according to data released by Brazilian research institute Imazon, The Guardian reports. That figure is 57 per cent higher than in the previous year and the worst since 2012.

The Amazon, the world's biggest rainforest, is vital to curbing climate change because of the carbon dioxide it absorbs from the atmosphere, but raging fires has been raising concerns worldwide.

According to climatologist Francisco Aquino, from the Geography Department of the Universidade Federal do Rio Grande do Sul, deforestation in the Amazon is directly correlated to the drought seen in Rio Grande do Sul.

"The humidity circulation in the atmosphere has been undergoing changes, and so have the water regimes. Adding it to human activity, this causes an environmental crisis," he said, adding that "crisis" is a good word for it at the moment.

Professor Aquino says that excessive deforestation causes changes in the water regime - the set of variations in rain and rivers - all over Brazil, not just in the Amazon.

"The Amazon has often supplied the south region and got a water deficit. The humidity it creates right now may not be enough to provide for itself. What the scientific community has been warning is that we're reaching the limit for the systems to augment these flaws and for the ecosystems to collapse," he said.

"They won't be able to recover if we don't stop logging. We've got record numbers in the Amazon due to lack of oversight, since somebody does logging and then creates a fire to clear the area. The fire spins out of control due to the region being drier than it should be."

Meteorologist Catia Valente, who is responsible for the Rio Grande do Sul Civil Defence Situation Room, says that the connection between both facts may not be easily noticeable.

According to her, peak deforestation periods are small in comparison to the time scale of climate change. However, Ms Valente emphasises that extreme events are becoming the rule.

"They have been more and more frequent and intense. Whether they're related to climate change, science can say," she said.

She notices that the presence of the La Nina phenomenon, which causes a cooling of Pacific Ocean waters, has had an enormous impact on rain distribution in Rio Grande do Sul in the last few years.

"In the summer of 2020, we had a prolonged drought, which extended into autumn. La Nina acted during the spring, disfavouring rain once again. We've had a few big rain events in the northern part of the state, but they were one-offs.

"Last year, we did not recover from the water deficit that had been happening since the summer. Thus far, we've had a hydrological deficit of 300mm to 800 mm accrued in the state," she said.

Ms Valente is one of the people responsible for sounding the alarm for extreme climate events in the area, which people can receive through text messages on their cell phones. And to her, the outlook is not good.

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A version of this article appeared in the print edition of The Straits Times on September 28, 2021, with the headline Chain reaction in the Amazon. Subscribe