It is a surprising and bold move that looks set to put the parallel and crucially important issues of energy supply and climate change - both mitigation and adaptation - right up the political agenda.
Add in the installation of rising political star Ed Miliband as secretary of state and there is certainly the feeling that Gordon Brown is at last taking the radical steps that he waited so long to take while Tony Blair's number two.
Without question the appointment of Ed Miliband is exciting. He is after all the man with the ear of the prime minister these days. And having been at Brown's side through much of his Treasury years he knows how to work with him and critically how to get things done.
And get things done he must. The last decade of wise words and ill-defined action by the Blair government means that his to-do list is vast and growing by the day.
This week, for example, the Committee on Climate Change recommended increasing the UK's carbon reduction target by 2050 from 50% to 80%.
And we also started to hear the pre-winter warnings that without investment in generation capacity and the national grid, the UK's lights will soon go out.
The week before we were condemned as way behind in investment in renewable technology making our renewable power one of the most expensive in Europe.
And Environment Secretary Hilary Benn reminded the Labour Party conference about the scale of the climate change adaptation challenge and warned that investment in flood defences would have to continue to rise.
Clearly Miliband's battles will be across many fronts as he attempts to steer the long-awaited Climate Change Bill home.
First, with the environment brief now split between two departments, he will have to swiftly find a clear role and mandate for the Environment Agency and its break-up now seems inevitable.
He will also have to quickly work out just what kind of relationship he wants from energy giants such as EON (will he back its controversial plans for the new Kingsnorth coal fired power station?) and EDF (how many new nuclear power stations will he demand, where, when and with what liabilities?).
Then there are the small matters of balancing the desire for renewable power sources with the needs of the planning system, airport expansion versus high speed rail, energy security, and don't forget Gordon's personal favourite carbon capture and storage.
Finally in these financially turbulent times he will have to make the case for investing the vital few percent of GDP that will, as Stern pointed out, reap reward later.
Fortunately Miliband has, we are told, both a big brain and a sense of humour. He'll need all of that and plenty of support - but it's an exciting moment and this could be your chance to save the planet.
Antony Oliver is the editor of NCE