Amazon tipping point

The importance of Amazon moisture for Brazilian agriculture south of the Amazon is complex but not trivial. Perhaps most important is the partial contribution of dry season Amazon evapotranspiration to rainfall in southeastern South America. Forests maintain an evapotranspiration rate year-round, whereas evapotranspiration in pastures is dramatically lower in the dry season. As a consequence, models suggest a longer dry season after deforestation.

In this article, Thomas E. Lovejoy, professor in the Department of Environmental Science and Policy at George Mason University and Carlos Nobre, Member of the Brazilian Academy of Sciences and Senior Fellow of World Resources Institute Brazil, believe that the sensible course is not only to strictly curb further deforestation, but also to build back a margin of safety against the Amazon tipping point, by reducing the deforested area to less than 20%, for the commonsense reason that there is no point in discovering the precise tipping point by tipping it.

Together, they assert that negative synergies between deforestation, climate change, and widespread use of fire indicate a tipping point for the Amazon system to flip to non-forest ecosystems in eastern, southern and central Amazonia at 20-25% deforestation.

This article was published in the journal, Science Advances 21 Feb 2018:Vol. 4, no. 2, eaat2340.

Amazon tipping point