Climate engineering through artificial enhancement of natural forcings: Magnitudes and implied consequences

This study uses a coupled Atmosphere-Ocean General Circulation Model to illustrate the character of resulting climate and circulation anomalies when both enhanced greenhouse (A2 scenario) and opposing geoengineering perturbations are considered. First we quantify the magnitude of the required perturbation and compare these artificial perturbations to the natural range of the respective forcing. Then, we test the effectiveness of the "correction" by looking at the regional climate response to the combined forcing.

It is shown that widespread warming could be reduced, but overcompensation in the tropics is necessary because sea ice loss in high latitudes cannot be reversed effectively to overcome higher ocean heat content and enhanced zonal winter circulation as well as the continuous IR forcing. The magnitude of new, greenhouse gas-countering anthropogenic forcing would have to be much larger than what natural forcing from volcanoes and solar irradiance variability commonly provide.