21 February, 2018

Committed sea level rise under the Paris Agreement and the legacy of delayed mitigation action


Matthias Mengel, Alexander Nauels, Joeri Rogelj, Carl-Friedrich Schleussner

Sea level rise is a major consequence of climate change that will continue long after emissions of greenhouse gases have stopped. The 2015 Paris Agreement aims at reducing climate-related risks by reducing greenhouse gas emissions to net zero and limiting global mean temperature increase. Here we quantify the effect of these constraints on global sea level rise until 2300, including Antarctic ice sheet instabilities.

We estimate median sea level rise between 0.7 and 1.2m, if net zero greenhouse gas emissions are sustained until 2300, varying with the pathway of emissions during this century. Temperature stabilisation below 2°C is insufficient to hold median sea level rise until 2300 below 1.5m.

We find that each 5 year delay in near-term peaking of CO2 emissions increases median year 2300 sea-level rise estimates by ca. 0.2m, and extreme sea level rise estimates at the 95th percentile by up to 1m. Our results underline the importance of near-term mitigation action for limiting long-term sea level rise risks.