A potential collapse of the Atlantic Meridional Overturning Circulation may stabilise eastern Amazonian rainforests

Abstract Observations and models suggest that the Amazon rainforest might transition to a savanna-like state in response to anthropogenic climate and land use change. Here, we combine observations of precipitation, temperature and tree cover with high-resolution comprehensive climate model simulations to investigate the combined effect of global warming and a potential Atlantic Meridional Overturning Circulation collapse on the Amazon. Our results show that, while strong warming lead to forest dieback, an Atlantic Meridional Overturning Circulation collapse would stabilize the Amazon by increasing rainfall and decreasing temperature in most parts. Although an Atlantic Meridional Overturning Circulation collapse would have devastating impacts globally, our results suggest that it may delay or even prevent parts of the Amazon rainforest from dieback. Besides the many negative consequences of its collapse, the interactions we identify here make a tipping cascade, i.e., that an Atlantic Meridional Overturning Circulation collapse would trigger Amazon dieback, appear less plausible.