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“The forest is no longer growing faster than it’s dying. This is bad – having the most productive carbon absorber on the planet switch from a sink to a source…”
The Amazon rainforest is now emitting more carbon dioxide than it is able to absorb, according to a new study.
Hundreds of aerial readings of emissions collected over the last decade showed that southeastern Amazon, in particular, has shifted from a ‘sink’ to a source of carbon dioxide.
The CO2 emissions amount to a billion tonnes a year, scientists have confirmed.
The study published in the journal Nature involved taking 600 vertical profiles of CO2 and carbon monoxide, which is produced by the fires, at four sites in the Brazilian Amazon from 2010 to 2018.
Researchers measured CO2 levels up to 4,500m above the forest. They found fires produced about 1.5bn tonnes of CO2 a year, with forest growth removing 0.5bn tonnes.
The 1bn tonnes left in the atmosphere corresponds to the annual emissions of the world’s fifth-biggest polluter – Japan.
Factors affecting the Amazon rainforest
Deforestation and an increasing warming trend have contributed to the carbon imbalance in the southeastern region of the Amazon, which has been experiencing rising temperatures and reduced rainfall in the dry season.
Fires deliberately set to clear space for beef and soy production has caused major destruction. Since 1970, the region’s tropical forests have declined by 17%, mostly to accommodate livestock rearing.
Deforestation surged to an all-time high last year while fires hit their highest level in June since 2007, Reuters reported.
In addition, changing weather patterns have reduced the region’s effectiveness as a buffer for climate change, and global warming is further aggravating the situation.
According to researchers, the largest tropical forest losing its power to absorb emissions is a stark warning that currbing emissions from fossil fuels is critical.
‘Sink to source’
Lead researcher Luciana Gatti from the National Institute for Space Research in Brazil said: “The first very bad news is that forest burning produces around three times more CO2 than the forest absorbs.
“The second bad news is that the places where deforestation is 30% or more show carbon emissions 10 times higher than where deforestation is lower than 20%.”
She added: “We have a very negative loop that makes the forest more susceptible to uncontrolled fires.”
Prof Scott Denning from Colorado State University called the aerial research ‘heroic’, the Guardian reported.
“In the south-east, the forest is no longer growing faster than it’s dying. This is bad – having the most productive carbon absorber on the planet switch from a sink to a source means we have to eliminate fossil fuels faster than we thought,” he said.
Politics
While other scientists who work in this field have said the latest findings are consistent with changes that several other studies have already shown, efforts to decrease deforestation in the region face an uphill political battle.
The government of Brazil’s president, Jair Bolsonaro, has long clashed with environmental groups, and world leaders, after Bolsonaro pledged to develop the region for farming and mining in January.
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