Harriet Walker: Imagine: our chance to get it right next time

Stories about potentially habitable planets reduce grown men to excitable boys wearing colanders on their heads and pretending the sofa is a spaceship. It's just the sort of pioneer spirit you don't get very often these days, now that we know so much about our own planet (except how to stop it self-destructing under the weight of our existence).

If we did up sticks to Gliese 581g – perhaps on an intergalactic Richard Branson spaceship with a bar in first class – places would be limited, so those in charge had better start making "who to leave behind" lists. For those who make the cut, the move would be a relief. The fact that Gaia theorist James Lovelock is booked on the inaugural Virgin space flight says it all. He knows what's going to happen on Earth and it won't be pretty.

This could be our chance of a new future with a virginal ozone layer and acres of rainforest we can cherish. There may be beaches to lounge on, canyons to yodel in, mountains to scale and valleys to explore, all free of the detritus that we trail in our wake. And everyone will be happy and get along. Or maybe that really is science fiction.