In the first programme Sir David explores why most scientists are so firmly convinced that this warming of the planet is not simply another cycle. He heads to Australia’s Great Barrier Reef to witness the devastating effects of coral bleaching caused by warming seas and tracks Arctic polar bears to reveal how melting ice is slowly leading to their decline.

In the second programme, Can We Save Planet Earth?, Sir David looks to the future at the impact climate change will have on current and future generations. He also finds out what steps can be taken to save the planet from dramatic change. Many experts believe that, at a certain level of C02 in the atmosphere, a “tipping-point” will be reached. Princeton climate scientist Steven Pacala believes this will release the “monsters behind the door”. Rising carbon emissions could mean the loss of entire ecosystems, such as the Arctic, and rising sea levels caused by melting ice could be catastrophic. In Bangladesh, for example, a rise of even half a meter could see 10 million people displaced.