Wow. Brightening up to fight climate change

Is climate change clouding your moods and you need some brightening up?

Scientists are experimenting with a wild idea to fight global warming — brightening up marine clouds by aerosol sprays so that they reflect more sunlight back into the atmosphere.

Really, the idea of using aerosol to reflect sunlight — geo-engineering — is geriatric. So is ‘cloud seeding’, which is a rainmaker, literally. And now, somebody has thought of combining the two for a “brilliant” effect.

But the Marine Cloud Brightening (MCB) programme of the Department of Atmospheric Sciences, University of Washington, USA, is somewhat different from conventional geo-engineering. Guess what they are spraying? Salt. Trillions of extremely tiny particles of sea salt sprayed into clouds increase the clouds’ density and reflective capacity.

Only, we don’t know by how much. There are specific regions of the ocean with clouds that could be more favourable for brightening in this way, though it is still uncertain how much brightening could be achieved in different regions, says MCB. If marine cloud brightening were ever to be used, which areas are brightened, and by how much, would determine how much climate cooling could be produced. Furthermore, we don’t know if there would be any negative side-effects. This uncertainty has attracted criticism from some quarters, especially from a formation called The Alliance for Just Deliberations on Solar Geoengineering. But MCB says it is only a scientific experiment.

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