Blocking solar radiation cannot restore a high-carbon world to its preindustrial climate.

Ben Kravitz of the Pacific Northwest National Laboratory in Richland, Washington, and his colleagues analysed results from 12 climate models simulating quadrupled atmospheric carbon dioxide levels, and a matching reduction in solar radiation.

Blocking the sunlight kept average global temperatures in check while preventing 97% of Arctic sea-ice loss, but the effects on temperature and precipitation varied by region, with the Arctic experiencing more warming and the tropics more cooling, as well as less rainfall in places.

The authors suggest that solar geoengineering cannot simultaneously correct for global and regional impacts from rising greenhouse-gas levels.

J. Geophys. Res. http://doi.org/nmz (2013)