Future AMOC evolution, impacts and abrupt changes (WP4)

Objective: Assess the key processes of future AMOC changes and identify indicators of abrupt changes and AMOC-related climate impacts with societal relevance.

Specifically:

  • Identify key processes and feedbacks governing AMOC response to abrupt-4xCO2 forcing;
    Assess and compare AMOC-related impacts and abrupt changes;
  • Derive precursors and indicators of AMOC-related abrupt changes;
  • Evaluate how close we may be to a tipping point.
Overview

Whereas a shutdown of the AMOC is one of the most dramatic change the ocean may undergo in the next few decades to centuries, with acknowledged likely far-reaching consequences, other less spectacular AMOC variability could also contribute to high impact climate events, possibly including abrupt changes or tipping points. In this WP, we will evaluate whether AMOC impacts intensify under abrupt CO2 forcing and whether AMOC changes to greenhouse gas forcing are sensitive to model horizontal resolution. It is anticipated that high resolution coupled simulations will have better fidelity of the ocean-atmosphere coupling, as well as the downstream development of atmospheric weather systems. Hence, we will use high resolution coupled climate simulations to diagnose the impact of AMOC on European and global climate variability. We will then assess to what extent coarse coupled models used for climate prediction underestimate the climate impacts of AMOC changes and hence potentially their predictability.