Geoengineering would require consensual global governance. Drought image via Shutterstock.

Predicting drought or rainfall in the desert

A new study by Professor Jim Haywood, from Mathematics at the University of Exeter, and colleagues suggests that sporadic volcanic eruptions in the northern hemisphere strongly influence the sea surface temperature and cause drought in the Sahel – the area of sub-Saharan Africa, just south of the Sahara desert. 

Accurate prediction of Sahelian drought using mathematical models based on volcanic eruptions has obvious implications for disaster relief and aid agencies.

The study goes further by modelling the impacts of continuous deliberate injection of sulphur dioxide into the stratosphere, which has been suggested as a potentially plausible measure to counterbalance the impacts of global warming. Results suggest deliberate unilateral aerosol injection into the northern hemisphere causes significant drought in the Sahel, while injection into the southern hemisphere causes a significant greening.

While on the face of it, this suggests that one could potentially inject into the southern hemisphere to make the Sahel a more hospitable and agriculturally viable region, Haywood and colleagues stress that other areas of the Earth have to be considered and that geoengineering would require consensual global governance.

For the full article, graphics and a video explanation see the Met Office page ‘Stratospheric aerosols and their impact on Sahelian rainfall’.

Date: 3 April 2013

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