View Full Version : Dimming the sun could save corals from bleaching and hurricanes

10-27-2017, 06:33 PM
Time for artificial planet coolers? A cooling “sunshade” for the planet could reduce harmful coral bleaching and the number of hurricanes, which damage reefs.

With the effects of climate change becoming increasingly apparent, the idea of squirting a cloud of sulphate aerosols into the upper atmosphere is being investigated by several groups of scientists. This would scatter some of the sun’s rays back into space, reducing the rate at which the Earth is warming.

Now a study by James Crabbe at the University of Bedfordshire, UK, and his colleagues examines what this form of geoengineering would do to the Caribbean region and its fragile reefs. “Corals are the rainforests of the sea, and if you lose them the impacts on ecosystems and people would be complex and far-reaching,” says Crabbe.

The team used computer models to simulate both the changing climate and rising seas between 2020 and 2069. They then modelled what would happen if solar radiation was artificially reduced. “We show very convincingly that, by injecting sulphur dioxide in the atmosphere, sea surface temperatures would decrease significantly by 2069,” says Crabbe.


The main source of sulfur dioxide in the air is industrial activity that processes materials that contain sulfur, eg the generation of electricity from coal, oil or gas that contains sulfur. Some mineral ores also contain sulfur, and sulfur dioxide is released when they are processed. In addition, industrial activities that burn fossil fuels containing sulfur can be important sources of sulfur dioxide.

Sulfur dioxide affects human health when it is breathed in. It irritates the nose, throat, and airways to cause coughing, wheezing, shortness of breath, or a tight feeling around the chest. The effects of sulfur dioxide are felt very quickly and most people would feel the worst symptoms in 10 or 15 minutes after breathing it in.

Those most at risk of developing problems if they are exposed to sulfur dioxide are people with asthma or similar conditions.