What causes climate change, and why should we be worried?

Climate change is bad. Not bad like one of those days when you can't get your hair to stay straight, but bad in a catastrophic, poo-your-pants kind of way. Luckily it's not inevitable, but stopping it means making some fairly major changes to the way we live, work and interact with each other: challenging corporate and political authority, reducing our impact on the environment and improving our communities and relationships with ourselves and other people.

Put simply, many of the things we do emit carbon dioxide and other greenhouse gases, and these gases trap the sun's heat, increasing global temperature. A rise of a few degrees is enough to tip us out of our relatively stable state into one where the climate is much less suited to human activity. Rising temperatures set positive feedback cycles in motion, such as the melting Siberia permafrost, which releases further gases and causes more warming.

Climate science is fairly complicated - and there is debate about some of the details, such as the exact 'safe' level for CO2 emissions in the atmosphere - but the overwhelming scientific consensus is that increasing emissions is a very, very bad idea. Scientists now believe that we are all but certain to see a rise in global temperatures of two degrees. This may sound minor, but would lead to dramatic rises in sea level and many more severe 'weather events'. Failing to keep our emissions in check could see global temperatures increase by six degrees or more - a truly terrifying prospect.

Global CO2 emissions have historically come from the richest nations in the West, but the effects of global warming will be felt first and hardest by those countries who are least responsible and most vulnerable. Rich nations are increasingly trying to lay the blame on developing nations, like China, whose emissions have risen sharply because we outsourced our factories and emissions them to take advantage of their cheaper labour. Climate change is not about 'pulling the ladder up behind us', but about cleaning up the mess that we in the West have created.

There's lots of information on the internet about climate change: some good, some bad, and some downright misleading. Plane Stupid recommends Climate Safety and the New Scientist's guide to climate change for the perplexed, both of which cut through the exaggeration and spin with a freshly-sharpened scalpel.