Geoengineering, cooling the earth

How to Cool Earth - At a Price/Scientific American

So if we can't do anything about the Sun, we can work to cool the Earth. And that's what geoengineering is about - deliberate actions taken to slow or reverse global warming. So far, very little research has gone into geoengineering or its possible side effects. Among the proposals are, injecting several million tonnes of sulphur dioxide into the stratosphere, spraying seawater into the air from wind-powered vessels, and building a sunscreen in space. But someday, if this giant sunshade were to fail, the accumulated CO2 will warm the Earth in one swoop. So till the research throws up something more conclusive, keep track of your carbon footprints and stay green.  more