Housing Minister Grant Shapps has unveiled the Government's definition of zero carbon homes that will apply to all properties built from 2016.

Shapps said that the "realistic" definition hits the right balance between delivering zero carbon homes and getting them built.

David Cameron's welcome pledge to step up cuts in carbon emissions boosts his government's green credentials, but its actions at home and abroad tell a different story. As David Cameron finally aims to put some muscle behind his supposed green credentials, by backing more ambitious domestic cuts in CO2 over the coming years, it's worth noting that there's still a fair amount of two-faced behaviour from his government.

Green campaigners praise David Cameron and his energy secretary, Chris Huhne, for setting bold new carbon emissions cuts. And so they should. The UK now has the toughest legally binding targets in the world, and with them the chance to be a leader in a job-rich green economic future. But that does not mean it has in place the policies to deliver.

The eyes of the world will be on South Africa from Sunday 27 November to Friday 9 December this year. Negotiators and political leaders from around the world will gather in Durban at the 17th Conference of the Parties to the UN Framework Convention on Climate Change (COP17).