In order to distract your attention from the end of the world as we know it resulting from COVID-19, I thought I would direct your attention to further evidence of the end of the world as we know it resulting from climate change. In a very interesting article published earlier this month in Nature Communications, the authors examined the pace of “regime shifts” in critical ecosystems, including the relationship between the size of ecosystems and the pace of the shifts. The results are not comforting. While shifts do take longer in larger ecosystems, they proceed relatively more quickly.
Here are the major conclusions:
First, we must prepare for regime shifts in any natural system to occur over the ‘human’ timescales of years and decades, rather than multigenerational timescales of centuries and millennia.
Second, the apparent long-term stability of the largest, least disturbed ecosystems is a deceptive guide to the potential speed of their collapse. Therefore, the self-organising mechanisms that help to instill systems with resilience prior to a tipping point may have limited ability to control the rate of collapse once a shift has been triggered.
Third, homogenously connected systems shift relatively less quickly, meaning that ecosystems that are already disturbed but stabilised, or those that are engineered, may be relatively slower to collapse because of the lack of vulnerable modular structures. Thus, although shifts in agroecosystems are expected due to climate change, their relatively slow transitions may offer vital time for adaptation.
Fourth, the ‘window of opportunity’ open to divert unsustainable system trajectories is comparatively short for relatively small systems, meaning contingency plans should be formulated in advance and ready to implement across localised systems recognised to be heading towards the brink.
Of course, given COVID-19, a good many of us may not be around to see this rather bleak future. Between the two, I am reminded of one of Keynes’s famous quotes:
In the long run, we are all dead.