Australian wildfires caused vast ocean algae blooms

Abstract

Intensified by prolonged drought and high temperatures, the wildfires that blazed through Australia’s bush in 2019–20 were severe, torching around 74,000 km 2 of eucalyptus forest. These fires spewed more than twice as much carbon dioxide as previously estimated, increasing the country’s anthropogenic carbon emissions by more than a third over the year before, according to a new analysis ( Nature 2021, DOI: 10.1038/s41586-021-03712-y ). The fires also released nutrient-containing aerosols into the atmosphere. Researchers have now linked these emissions to an extraordinary algae bloom bigger than the Australian continent that formed several thousand kilometers away in the Southern Ocean ( Nature 2021, DOI: 10.1038/s41586-021-03805-8 ). With new high-resolution satellite measurements, a team led by meteorologist Ivar van der Velde of SRON Netherlands Institute for Space Research analyzed atmospheric carbon monoxide concentrations during the fires, which lasted from November 2019 to January 2020. Using the known ratio of CO to