Global Melting? The Economics of Disintegration of the Greenland Ice Sheet

Concerns about the impact on large-scale earth systems have taken center stage in the scientific and economic analysis of climate change. The present study analyzes the economic impact of a potential disintegration of the Greenland Ice Sheet (GIS). The method is to combine a small geophysical model of the GIS with the DICE integrated assessment model. The result shows that the GIS is likely to disappear over the next millennium or so without climate policy, but an active climate policy may prevent the GIS from crossing the threshold of irreversibility. Additionally, the study estimates the impact of the GIS on the social cost of carbon (SCC) and finds that adding GIS dynamics would add less than 5% to the SCC under alternative discount rates and estimates of the GIS dynamics. Simulations of geo-engineering options indicate that the dynamics of disintegration and rebuilding are extremely asymmetric, implying that GIS disintegration should be treated as irreversible.