{"id":298962,"date":"2021-07-14T20:02:28","date_gmt":"2021-07-14T17:02:28","guid":{"rendered":"https:\/\/en.buradabiliyorum.com\/warming-deforestation-turn-amazon-into-source-of-carbon-dioxide\/"},"modified":"2021-07-14T20:02:28","modified_gmt":"2021-07-14T17:02:28","slug":"warming-deforestation-turn-amazon-into-source-of-carbon-dioxide","status":"publish","type":"post","link":"https:\/\/buradabiliyorum.com\/en\/warming-deforestation-turn-amazon-into-source-of-carbon-dioxide\/","title":{"rendered":"#Warming, deforestation turn Amazon into source of carbon dioxide"},"content":{"rendered":"

“#Warming, deforestation turn Amazon into source of carbon dioxide<\/strong>”<\/p>\n

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\n The Amazon basin contains about half of the world’s tropical rainforests, which are more effective at soaking up and storing carbon that other types of vegetation.
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Climate change and deforestation have flipped a large swathe of the Amazon basin from absorbing to emitting planet-warming CO2<\/sub>, a transformation that could turn humanity’s greatest natural ally in the fight against global warming into a foe, researchers reported on Wednesday.<\/p>\n


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Hundreds of high-altitude air samples collected over the last decade showed that southeastern Amazon, in particular, has shifted from a “sink” to a source of carbon dioxide, the main greenhouse gas, they reported in the journal Nature<\/i>.<\/p>\n

Terrestrial ecosystems worldwide are crucial as the world struggles to curb CO2<\/sub> emissions, which topped 40 billion tonnes in 2019. <\/p>\n

Over the last half century, plants and soil have consistently absorbed more than a quarter of those emissions, even as CO2<\/sub> pollution increased by 50 percent. <\/p>\n

The Amazon basin contains about half of the world’s tropical rainforests, which are more effective at soaking up and storing carbon than other vegetation.<\/p>\n

If Amazonia\u2014with 450 billion tonnes of CO2<\/sub> locked in its trees and soil\u2014were to become a consistent source rather than a “sink” of CO2<\/sub>, tackling the climate crisis would be vastly more challenging.<\/p>\n

Several factors have driven the transition in the eastern Amazon, according to the study.<\/p>\n

“Deforestation and forest degradation both reduce Amazonia’s capacity to act as a carbon sink,” the authors noted.<\/p>\n

Since 1970, the region’s tropical forests have declined by 17 percent, mostly to accommodate pasture for raising cattle and the crops that feed them. <\/p>\n

Forests are general<\/a>ly cleared with fire, which both releases vast amounts of CO2<\/sub> and reduces the number of trees available to absorb it.<\/p>\n

Climate change itself is also a key factor. <\/p>\n

Dry-season temperatures have risen by nearly three degrees Celsius compared to pre-industrial levels, trip<\/a>le the global year-round average.<\/p>\n

Tipping points<\/b><\/p>\n

Taken together, these drivers “cast doubt on the ability of tropical forests to sequester large amounts of fossil-fuel-derived CO2<\/sub> in the future,” Scott Denning, an atmospheric scientist at Colorado State University, noted in a commentary, also in Nature.<\/p>\n

To what extent the Amazon basin was losing its ability to soak up CO2<\/sub> has long been a burning question, but satellite data\u2014partly due to persistent cloud cover\u2014has not been able to provide a complete answer.<\/p>\n

To get around that problem, researchers led by Luciana Gatti of the National Institute for Space Research in Sao Jose dos Campos in Brazil used aircraft to collect nearly 600 CO2<\/sub> and carbon monoxide samples, from 2010 to 2018, at elevations up to 4.5 kilometres (2.8 miles) above the forest floor.<\/p>\n

Northwestern Amazon, they found, was in carbon balance, absorbing as much CO2<\/sub> into the atmosphere as it gave off.<\/p>\n

But the eastern Amazon\u2014especially during the dry season\u2014emitted far more than it absorbed.<\/p>\n

Another recent study, using different methodology, found that the Brazilian Amazon released nearly 20 percent more CO2<\/sub> over the last decade than it absorbed from 2010 to 2019. <\/p>\n

Above a certain threshold of global warming, global warming could see the continent’s rainforest tip into a much drier savannah state, recent research has shown.<\/p>\n

This would have devastating consequences both to the region, which currently harbours a significant percentage of the world’s biodiversity, and globally.<\/p>\n

The Amazon rainforest is one of a dozen so-called “tipping points” in the climate system.<\/p>\n

Ice sheets atop Greenland and the West Antarctic, Siberian permafrost loaded with CO2<\/sub> and methane, monsoon rains in South Asia, coral reef ecosystems, the jet stream\u2014all are vulnerable to point-of-no-return transitions that would radically alter the world as we know it.<\/p>\n\n

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Climate change: Amazon may be turning from friend to foe\n <\/p><\/div>\n

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\n More information:<\/strong>
\n Luciana V. Gatti et al, Amazonia as a carbon source linked to deforestation and climate change, Nature<\/i> (2021). DOI: 10.1038\/s41586-021-03629-6<\/a><\/p><\/div>\n

\n \u00a9 2021 AFP<\/p>\n

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Citation<\/strong>:
\n Warming, deforestation turn Amazon into source of carbon dioxide (2021, July 14)
\n retrieved 14 July 2021
\n from https:\/\/phys.org\/news<\/a>\/2021-07-deforestation-amazon-source-carbon-dioxide.html<\/p>\n

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