Humans have been counting on the Amazon Basin absorbing a great deal of atmospheric carbon produced by economic activity. Over the past half-century plants and soil have taken up 30% of emissions with the oceans contributing 20% even as the amount of emissions have increased 50%. The Amazon contains about half of the world's tropical rainforest, which is more effective sponging and storing carbon than other types of vegetation. Not any more. A new study alarmingly reveals that for the past ten years the Brazilian Amazon is a net emitter of carbon dioxide by about 20%. The authors reported in Nature Climate Change that the region gave off 16.6 tons of carbon dioxide while absorbing only 13.9 tons from 2010 through 2019. Scientists suspected the Amazon might have flipped to being a net emitter. They are not sure if this process can be reversed.
As readers might expect deforestation and wildfires have been the biggest contributors to the change. Deforestation increased four fold in 2019--the year anti-nature President Jair Bolsonaro was elected to office--compared to the previous two years. Bolsonaro has been pursuing a exploitation policy, encouraging forest clearances and weakening environmental protections. Degradation of existing forest through fragmentation, selective cutting and damaging fires that do not destroy trees causes three times more emissions than outright destruction. [illegal fire in the Amazon, photo: Getty Images]
One flicker of hope is that the study only examined the Brazilian Amazon. If the Amazonian Basin is looked at as whole, scientists think that the Basin is carbon neutral. No longer a carbon sink to assist man, reducing carbon in the global atmosphere will be more difficult. The massive forest is also threatened by drought, which could turn it into savanna. Grassland is great for cattle, which may be the end game for the exploiters.
