Approaching a state shift in Earth’s biosphere

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. The plausibility of a planetary-scale 'tipping point' highlights the need to improve biological forecasting by detecting early warning signs of critical transitions on global as well as local scales, and by detecting feedbacks that promote such transitions. It is also necessary to address root causes of how humans are forcing biological changes.

When did the Anthropocene begin? A mid-twentieth century boundary level is stratigraphically optimal

“…We agree that greater changes likely lie ahead and that the stratigraphic character of the Anthropocene will probably appear different from a far future perspective. However, the scale of these projected changes in the geological near future argue for perturbations of such as the biosphere (Barnosky et al, 2012) and ocean/atmosphere system (Tyrrell, 2011) that are commensurate with period/era level changes. The Anthropocene already has a robust geological basis, is in widespread use and indeed is becoming a central, integrating concept in the consideration of global change (e.g.…”

Science and politics: Hello, Governor

“…It was June 2012 and Barnosky, a palaeoecologist at the University of California, Berkeley, had days earlier published a headline-grabbing Nature paper claiming that Earth faced a 'planetary-scale tipping point' because of human-caused climate disruptions, species extinctions, ecosystem loss, pollution and population growth 1 . Among his co-authors was his wife, Elizabeth Hadly, also a palaeoecologist, at Stanford University in California.…”

O paradigma agroecológico e as crises da sociedade contemporânea: contribuições socioantropológicas na perspectiva da teoria mimética

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