Is the Amazon rainforest really reaching a tipping point?

In 10 seconds? A new paper states that three-quarters of the Amazon rainforest has suffered significant harm over the past twenty years due to human activity. The conclusion is that this ecosystem might be reaching a point from which it cannot recover, instead becoming a savanna.

How did they conclude this? The authors considered only areas of the forest which comprise 80% or more evergreen broadleaf vegetation and which do not show major, on-the-ground human activity. Satellite observations between 1991-2016 were used to calculate two indicators: The amount of vegetation mass and the amount of photosynthesis activity. The researchers then calculated the trends in these values, finding decreases in photosynthesis activity which were compared to a stable trajectory to work out a value describing the “resilience” of the forest, i.e. to what extent it can recover after disturbances. Over 75% of the studied areas showed decreasing resilience, primarily after the early 2000s.