More frequent abrupt marine environmental changes expected

Published 16 February 2024 Science Leave a Comment
Tags: chemistry, globalmodeling, methods, modeling

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.

Key Points

• There is an elevated occurrence of abrupt changes in key ocean state variables under human-induced climate forcing
• The occurrence of abrupt changes in the upper ocean peaks around the maximum of the rate of change in human-induced forcing
• A multi-centennial legacy is expected for abrupt shifts in environmental conditions, long after a stop of anthropogenic CO₂ emissions

Heinze C., Michel C., Torsvik T., Schwinger J. & Tjiputra J. F., 2024. More frequent abrupt marine environmental changes expected. Geophysical Research Letters 51: e2023GL106192. doi: 10.1029/2023GL106192. Article.

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