Fight for the Future

Having explained the science behind global warming, and addressed the arguments of the climate change sceptics earlier in the series, in this third and final part Dr Iain Stewart looks at the biggest challenge now facing climate scientists. Just how can they predict exactly what changes global warming will bring?

It's a journey that takes him from early attempts to model the climate system with dishpans, to supercomputers, and to the frontline of climate research today: Greenland. Most worryingly, he discovers that scientists are becoming increasingly concerned that their models are actually underestimating the speed of changes already under way.