大象传媒

The recent Stern Review painted a disturbing picture of the Earth in the grip of climate change. Rising sea levels could displace 200 million people and up to 40% of species may face extinction.A number of prominent scientists and economists fear that we won't be able to cut carbon emissions quickly enough to avert catastrophe. Now some are considering a radical alternative - re-engineering our planet.

In this week's Frontiers, Peter Evans meets the engineers and scientists devising schemes to rebalance the Earth's climate. Collectively termed 'geo-engineering', these ideas range from sending a giant sunshade into space, to making seaclouds shinier. So would these projects work, and should we consider messing with the world's climate even further? To answer these questions, Peter is joined in the studio by Ken Caldeira, a climate specialist at the Department of Global Ecology, in the Carnegie Institution in the US and Greg Benford, a science-fiction writer and physicist at the University of California, Irvine.