An article published yesterday in Nature Sustainability warns that current estimates of how soon various environmental tipping points might occur are far too conservative. You can download the article here. This is the abstract:
A major concern for the world’s ecosystems is the possibility of collapse, where landscapes and the societies they support change abruptly. Accelerating stress levels, increasing frequencies of extreme events and strengthening intersystem connections suggest that conventional modelling approaches based on incremental changes in a single stress may provide poor estimates of the impact of climate and human activities on ecosystems. We conduct experiments on four models that simulate abrupt changes in the Chilika lagoon fishery, the Easter Island community, forest dieback and lake water quality—representing ecosystems with a range of anthropogenic interactions. Collapses occur sooner under increasing levels of primary stress but additional stresses and/or the inclusion of noise in all four models bring the collapses substantially closer to today by ~38–81%. We discuss the implications for further research and the need for humanity to be vigilant for signs that ecosystems are degrading even more rapidly than previously thought.
The moral of the story is that we have not been served well by the laser-like focus on climate change over the past couple of decades. Other environmental pressures are important as well, and when combined with global heating there is the potential for catastrophic breakdown of major ecosystems within the next few decades. Specifically, they suggest that the IPCC warning of a tipping point in the Amazonian forest system by 2100 may be several decades too optimistic.
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