Carbon emissions from central government will be cut by 10% in the next 12 months, prime minister David Cameron announced on Friday, the most ambitious commitment on UK government emissions ever made.
Government department headquarters will also publish online in real time their energy use so the public can hold ministers and civil servants to account for their carbon footprint.
A government steering group will be established to ensure the delivery of this emissions target. The steering group will be chaired by the energy and climate change secretary Chris Huhne, and comprise representatives from key departments and the private sector.
The PM will write to all colleagues to reaffirm this shared commitment and invite them to bring forward their plans to help meet this common target.
Speaking to staff at the Department of Energy and Climate Change, the prime minister said: "I don't want to hear warm words about the environment. I want to see real action. I want this to be the greenest government ever. In fact, we've made a good start. Someone pointed out when you mix blue with yellow – you get green.
"So today, taking our lead from 10:10, I commit us to a ten percent reduction in carbon emissions across central government in the next twelve months. You'll be driving this forward. But I have also made sure all cabinet ministers are involved, developing plans to show how they will meet their share.
"And the public will be involved too – because we're going to publish the energy use of government headquarters in real-time, so people can hold us to account for our performance.
"And to those who say this is insignificant, remember this: the UK's public sector has a bigger carbon footprint than the entire waste industry; if we do this, we'll cut the Government's energy bills by hundreds of millions of pounds."
The new secretary of state for energy and climate change Chris Huhne has now started work, joined by Charles Hendry and Greg Barker as ministers of state.
Chris Huhne outlined his priorities in his new role: "Climate change is the greatest threat to our common future. We have a very short period of time to tackle the problem before it becomes irreversible and out of control.
"A lot of progress has been made, but we must now go further, faster and turn targets into real change.
"This is a coalition to provide strong and stable government for this country. The benefits of the low carbon economy are agreed between both parties, this is a priority agenda common to both manifestos.
"Together we have the opportunity to make this the greenest government in our history. And to put energy security, for too long a second order issue, at the heart of the UK's national security strategy. I intend to make decisions put off for too long to fundamentally change how we supply and use energy in Britain. To make it far easier for people to make their homes more energy efficient to reduce wasted energy and cut their bills. To give the power industry the confidence it needs to invest in low carbon energy projects. To create jobs and growth right across the low carbon economy. And to use every influence we have internationally to get a global deal to tackle climate change."