Dry seasons have become more intense
The researchers estimate that about 1-2 per cent of all forest loss in the Amazon is caused by this vicious cycle alone.
Dry seasons in the Amazon have become more intense in recent years leading to greater forest loss as trees die. On average the Amazon rainforest receives about 2.2 meters of rain each year. Much of this water comes sweeping in on winds from the Atlantic Ocean but the forest itself provides a substantial part of rainfall; water evaporates from leaves and blows downwind to fall as rain elsewhere in the forest.
The rain falling in wet seasons helps the forest survive dry seasons as water is readily available in soils and wood making fires less likely. Any changes to rainfall patterns can then affect the Amazon’s resilience and increase the risk of a tipping point.
Indeed, separate research published in Nature (4 March) shows the Amazon carbon sink is declining and the forest risks becoming an emitter of carbon with decades.
Restoring Amazon's resilience
Although deforestation rates in the Amazon have been declining substantially over the last two decades, recently they have been on the rise again.
“Until around 2012, Brazil showed that strong policies can control deforestation and forest fires in the Amazon, even during extreme drought. Yet, now lawmakers are undermining these policies. If we want to maintain the Amazon forest resilient, we must restore its governance, which will now require global action,” says Flores.