Net zero emissions target in peril as tropical forests absorb less CO2

https://www.newscientist.com/article/2236228-net-zero-emissions-target-in-peril-as-tropical-forests-absorb-less-co2/

By Adam Vaughan
4 March 2020

Scientists have warned that the world will have to reduce carbon emissions to net zero before 2050, after they discovered that tropical forests are losing their ability to remove CO2 from the atmosphere.

Climate change models predict that forests in Africa and the Amazon will act as a sink for carbon emissions well into the second half of this century, but now Simon Lewis at the University of Leeds, UK, and his colleagues have found that the Amazon could flip into a net emitter of carbon in as little as 15 years.

“It’s grim, so grim. It’s the most worrying paper I’ve written,” says Lewis.

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In recent years, there have been growing calls to cut global emissions to net zero by 2050 to avoid temperature rises of more than 1.5°C. But this deadline is based on climate models that assume tropical forests will remain a carbon sink in the second half of this century. As that no longer seems likely, Lewis says we will “need faster and greater cuts to get to net zero” sooner than 2050.

Stopping deforestation, which has exploded to a 10-year high in Brazil, will also be key, because disrupted forests are more likely to dry out and release CO2.

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