SPACE MIRRORS TO DRY OUT THE US AND EURASIA, TO "SAVE THE PLANET"

June 19, 2012 - Installing huge mirrors in space would help reverse global warming, but they would come at a price: less rain for the Americas and northern Eurasia.

Previous studies have shown that geoengineering can not restore both temperature and rain to previous levels, but they could not specify what a geoengineered climate would look like.

Hauke Schmidt of the Max Planck Institute for Meteorology in Hamburg, Germany, and his colleagues played out the same simple scenario in four distinct climate models. In every one, he quadrupled carbon dioxide levels from pre-industrial levels. Then, to mimic the impact of space-borne mirrors, he reduced the amount of incoming sunlight to precisely compensate for the extra trapped heat.

Decreasing incoming sunlight brought the typical international temperature back down to its pre-industrial 13.6 °C, but the poles warmed and the tropics cooled. International rainfall dropped, with parts of North and South America and northern Eurasia receiving 10 to 20 per cent less (Earth System Dynamics, DOI: 10.5194/esd-3-63-2012). This means that space mirrors may not save the US from the severe droughts predicted for later this century.

Sources and more information:

• Space mirrors will dry out US and Eurasia