Newly released satellite images have shown that tropical Africa emits billions of tonnes of carbon.
The images show Africa – affected by drought and changing land use – emits as much carbon dioxide each year as 200 million cars.
Two NASA satellite missions—Japanese Greenhouse Gases Observing SATellite (GOSAT) and the Orbiting Carbon Observatory (OCO-2) carried out the survey for over a decade.
“The tropics are home to one-third of Earth’s three billion trees and their stored carbon, and yet we are only scratching the surface of understanding how they are responding to changes in climate,” said Professor Paul Palmer, of the University of Edinburgh’s School of GeoSciences.
“We anticipate that satellite data will continue to improve that situation,” he added.
Repeated droughts in Ethiopia and soil degradation in West Africa helped push emission levels much higher.
Other noticeable trends include land-use change, burning extent, and possibly soil carbon stocks.
Researchers say the findings will help re-prioritise decadal science challenges for the carbon cycle community, particularly in the context of the Paris Agreement that implicitly relies on the continued operation of natural carbon sinks.