More Frequent Abrupt Marine Environmental Changes Expected

Abstract

We quantify an elevated occurrence of abrupt changes in ocean environmental conditions under human-induced climate forcing using Earth system model output through a novel analysis method that compares the temporal evolution of the forcings applied with the development of local ocean state changes for temperature, oxygen concentration, and carbonate ion concentration. Through a multi-centennial Earth system model experiment, we show that such an increase is not fully reversible after excess greenhouse gas emissions go back to zero. The increase in occurrence of regional abrupt changes in marine environmental conditions has not yet been accounted for adequately in climate impact analyses that usually associate ecosystem shifts large-scale variability or extreme events. Estimates for remaining greenhouse gas emission targets need thus to be more conservative.