There’s a new scientific paper out in the journal Nature called “Approaching a state shift in Earth’s biosphere.” In a sane world, it would be front page news. This is from the abstract:
Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence. [my emphasis]
As examples of past global state shifts, the authors cite the Cambrian explosion (“a conversion of the global ecosystem from one based almost solely on microbes to one based on complex, multicellular life,” which took a comparatively brief 30 million years), the Big Five mass extinctions, and the last glacial-interglacial transition, which started about 14 thousand years ago.