Fifth of the Amazon emits more CO2 than it absorbs

A new study shows how deforestation for livestock farming is pushing the rainforest towards a dangerous tipping point

When you’re fighting for your life and your back is against the wall, the last thing you need is for your friends to turn against you.

But that is just what a new scientific study has revealed is happening in the Amazon, where a fifth of the vast rainforest we rely upon to slow the effects of the climate emergency is now emitting more carbon dioxide than it stores.

Scientists have found that the natural order of things has been reversed across an astonishing 1.1 million square kilometres of the south-eastern Amazon basin, which loggers have been targeting to create beef farms and ranches or grow soy for livestock feed. More than half the rainforest could be lost in the next 30 years if the business of logging continues as usual.

The Amazon, which covers more than 5.5 million square kilometres, is one of the world’s greatest carbon sinks, meaning its trees remove carbon from the atmosphere and trap it. Chopping down those trees means the carbon is released back into the atmosphere.

The data has been gathered over a decade by aircraft flown fortnightly across the Amazon to record the levels of greenhouse gases. Just as with the rapidly melting icecaps at the world’s poles, as well as the so-called “third pole” – the glaciers of the Himalayas, which are retreating at an unprecedented rate – the experts fear the rainforest may soon reach a tipping point beyond which it will not recover.

The scientific effort has been led by Professor Luciana Gatti, of Brazil’s National Institute for Space Research, who told BBC Newsnight: “We observed that this area in the southeast is an important source of carbon. And it doesn’t matter whether it is a wet year or a dry year: 2017-18 was a wet year, but it didn’t make any difference.”

Her study co-author, Carlos Nobre, a researcher at the University of Sao Paulo, said the Amazon used to be “a very strong carbon sink [in the 1980s and 1990s], perhaps extracting two billion tonnes of carbon dioxide a year from the atmosphere. Today, that strength is reduced perhaps to 1 to 1.2 billion tonnes of carbon dioxide a year” – roughly three times the emissions of the UK in 2018 – and that doesn’t take into account emissions produced by deforestation and the recent fires across Brazil.

Nobre added that the Amazon would reach a tipping point once 20-25 per cent of the rainforest was cleared. “Today we are at about 17 per cent.”

The research, which has yet to be published, makes it clear that changing the way we use land for our own gain, particularly to raise livestock for human consumption, is vital if the Amazon – and the planet – is to be saved. And the first step is to stop logging.

“What I could suggest is a moratorium, like five years, with no deforestation, no fires, and then go to study and observe if we can reverse this process,” said Professor Gatti. “Because we need to try something if we don’t want to lose the Amazon.”

 

Posted on Categories: