Working Paper: NBER ID: w7476
Authors: Klaus Keller; Kelvin Tan; François MM Morel; David F Bradford
Abstract: Climate modelers have recognized the possibility of abrupt climate changes caused by a reorganization of the North Atlantic's current pattern (technically known as a thermohaline circulation collapse). This circulation system now warms north-western Europe and transports carbon dioxide to the deep oceans. The posited collapse of this system could produce severe cooling in north-western Europe, even when general global warming is in progress. In this paper we use a simple integrated assessment model to investigate the optimal policy response to this risk. Adding the constraint of avoiding a thermohaline circulation collapse would significantly reduce the allowable greenhouse gas emissions in the long run along an optimal path. Our analysis implies that relatively small damages associated with a collapse (less than 1 % of gross world product) would justify a considerable reduction of future carbon dioxide emissions.
Keywords: climate change; thermohaline circulation; greenhouse gases; optimal policy
JEL Codes: Q20; Q30; D90
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| greenhouse gas concentrations (Q54) | surface water temperature (Q25) |
| surface water temperature (Q25) | water density (Q25) |
| water density (Q25) | deepwater formation rates (Y10) |
| deepwater formation rates (Y10) | THC collapse (Y50) |
| THC collapse (Y50) | regional climate impacts in Northwestern Europe (Q54) |
| policy choices (D78) | environmental outcomes (Q56) |