Trying to predict climate change is hard. There are lots of factors involved – air temperature, sea temperature and cloud cover all play a part – as do dozens of other variables. Therefore, there are a huge number of calculations involved.

One solution is for scientists to use the largest supercomputer they can find. But even the biggest supercomputers are only so good. You can do better. Using a technique known as distributed computing, we’re hoping to harness the power of thousands of PCs around the world. If 10,000 people sign up, we’ll be faster than the world’s biggest computer. And we’re hoping to be even better than that.