A Planetary Survival Guide/New Scientist

The Sun has a little problem, they say. No, it's not turning red with envy — with the moon getting all the attention — but it's turning into a bloated red giant all the same. In 1.1 billion years, the Sun will begin heating up and in about seven billion years, the Sun would have swallowed the Earth. The only way out of this is to flee the Earth. But how? Fire up rockets and relocate the whole of mankind to another planet in about a billion space shuttle launches. Or even move Earth away from the Sun. But planetary orbits are shaped by the gravitational pulls of their neighbours, so moving the Earth will change their orbits. So maybe, it's best then to leave the planets alone.

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.

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