An Amazon Tipping Point?

Soaring deforestation coupled with the destructive policies of Brazil’s far-right president, Jair Bolsonaro, could push the Amazon rainforest dangerously to an irreversible “tipping point” within two years, a prominent economist has said. After this point the rainforest would stop producing enough rain to sustain itself and start slowly degrading into a drier savannah, releasing billions of tonnes of carbon into the atmosphere, which would exacerbate global heating and disrupt weather across South America.

“It’s a stock, so like any stock you run it down, run it down – then suddenly you don’t have any more of it,” said de Bolle,

The warning came in a policy brief published this week by Monica de Bolle, a senior fellow at the Peterson Institute for International Economics in Washington DC. De Bolle is also head of the Latin American studies programme at Johns Hopkins University.  Some believe the tipping point is still 15 to 20 years away, while others say the warning accurately reflects the danger that Bolsonaro and global heating pose to the Amazon’s survival. Bolsonaro has vowed to develop the Amazon, and his government plans to allow mining on protected indigenous reserves. Amazon farmers support his attacks on environmental protection agencies. His business-friendly environment minister, Ricardo Salles, has met loggers and wildcat miners, while deforestation and Amazon fires have soared since he assumed office in January.  Brazil’s space research institute, INPE, reported that deforestation in August was 222% higher than in August 2018.

Maintaining the current rate of increase INPE reported between January and August this year would bring the Amazon “dangerously close to the estimated tipping point as soon as 2021 … beyond which the rainforest can no longer generate enough rain to sustain itself”, de Bolle wrote.  At a US Congress committee on preserving the Amazon. She said, “If Bolsonaro is serious about developing the Amazon without paying any attention to sustainability or maintaining the forest’s standing, these rates would happen within his mandate,” she said.

Claudio Angelo of the Climate Observatory – an umbrella of non-profit environmental groups – said he thought de Bolle’s calculations were too pessimistic

Carlos Nobre, one of Brazil’s leading climate scientists and a senior researcher at the University of São Paulo’s Institute for Advanced Studies, questioned her calculation that estimated deforestation would quadruple from an estimate of nearly 18,000 km2 this year to nearly 70,000 km2 by 2021.

“It seems very improbable to me – the projected deforestation increase is more an economic calculation than ecological,” he said. However, he added: “We are seeing an increase in deforestation, I am not questioning this.” Last year, Nobre argued in an article written with celebrated American conservation biologist Thomas Lovejoy that the Amazon tipping point could happen in eastern, southern and central Amazonia when 20% to 25% of the rainforest has been felled – not expected for 20 to 25 years. He has since brought forward his prediction by about five years. “The Amazon is already 17% deforested, so when you calculate at the current rate of deforestation, this 20% to 25% is reached in 15 to 20 years,” he said. “I hope she is wrong. If she is right, it is the end of the world.”

But Lovejoy, a professor at George Mason University in Fairfax, Virginia, said that de Bolle’s projection could come true because global heating, soaring deforestation and an increase in Amazon fires have created a “negative synergy” that is accelerating its destruction – citing droughts in recent years as a warning sign.

“We are seeing the first flickering of that tipping,” he said. “It’s sort of like a seal trying to balance a rubber ball on its nose … the only sensible thing to do is to do some reforestation and build back that margin of safety.”

https://www.theguardian.com/environment/2019/oct/23/amazon-rainforest-close-to-irreversible-tipping-point