Large forests such as the Amazon rainforest act as the land-based lungs of the planet; absorbing carbon dioxide and exhaling oxygen. Within limits, this process can offset some of the carbon released into the atmosphere by human activity. However, in a new paper in Global Change Biology, scientists from Stanford University highlight an increased release of carbon dioxide resulting from additional warming and drought events.
The study’s lead author, Caroline Alden explains:
“We see that the carbon balance in the Amazon can change quickly in response to climate events. Heat anomalies during the wet season are strongly correlated with increased carbon loss in the same month, and lower-than-average rainfall during the wet season is correlated with increased carbon loss in the following month.”
The concern is that the release of carbon during the hot and dry spells that are expected to increase as a result of climate change will more than counteract the carbon absorption seen in a more benign climate. Over time, the world’s rainforests may shift from being the lungs of the planet to being an additional contributor to already too high levels of atmospheric carbon dioxide.