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The enormous and devastating Australian bushfires of 2019-2020 released more than twice the amount of carbon dioxide than previously thought, a new study has revealed.

During that Australian summer season, fires ripped through an especially large area in the coastal regions of Victoria and New South Wales.

Around 74,000 km2 – an area almost the size of Scotland – of eucalyptus forest went up in flames, triggering mass evacuations and killing or displacing three billion animals.

The fires were already known to have released large amounts of CO2 into the atmosphere, but the latest analysis found in fact 715 teragrams of CO2 were emitted between November 2019 and January 2020.

This is more than twice the amount previously estimated and surpasses Australia’s normal annual fire and fossil fuel emissions by 80%.

The report, published in the peer-reviewed journal Nature, said the fact that fires were "driven partly by climate change" makes "better-constrained emission estimates particularly important".

The link with climate change, and the expectation that fires will become more frequent in future, suggests that "part of the CO2 emitted by these fires will not be sequestered by vegetation regrowth".

It warned of a vicious cycle of carbon dioxide from the fires building up in the atmosphere, contributing to climate change, which in turn drives more fires.

Globally, wildfire emissions are roughly equivalent to 22% of all fossil fuel emissions, the report said.

The wildfires also released vast amounts of aerosols, containing nitrogen and iron.

These are likely to have fuelled vast plankton blooms thousands of kilometres away in the Southern Ocean, a separate study in Nature found, highlighting the complex links among wildfires, ecosystems and the climate.

"It has been suggested that the oceanic deposition of wildfire aerosols can relieve nutrient limitations and, consequently, enhance marine productivity but direct observations are lacking," the study into the blooms said.

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