The tropical ecosystems contain massive stores of carbon with a high vulnerability to anthropogenic climate change. With the “sparseness of ground-based measurements,” the estimates as to how much carbon has been sunk into the topic and how much has been released retained a great margin of error.
A lot of uncertainty for an important metric of a pressing global problem. As noted in the Nature Communications article, the knowledge of the net sink or net contributor to atmospheric carbon levels remains uncertain. These labelled +ve and -ve, respectively, for net annual source or net annual sink for carbon.
By “sink,” this means something akin to the oceans be sinks. In that, the oceans and the tropics absorb more carbon than they emit. They hold the carbon as opposed to releasing it. The release contributing to the levels of carbon in the atmosphere, as noted at levels of parts per million.
The paper published, based on independent – rather than dependent – satellite data sets, shows the land tropics to be +ve as opposed to -ve, or net annual sources rather than net annual sinks of carbon – not a positive finding for those wishing for easier solutions to the problem of human-induced global warming.
Carbon dioxide emissions from the North Africa region are higher than previously estimated in other words.
As stated, “These pan-tropical estimates reflect unexpectedly large net emissions from tropical Africa… The largest carbon uptake is over the Congo basin, and the two loci of carbon emissions are over western Ethiopia and western tropical Africa, where there are large soil organic carbon stores and where there has been substantial land use change. These signals are present in the space-borne CO2 record from 2009 onwards.”
Palmer, P.I. et al. (2019, August 13). Net carbon emissions from African biosphere dominate pan-tropical atmospheric CO2 signal. Retrieved from https://www.nature.com/articles/s41467-019-11097-w.