http://blogs.telegraph.co.uk/news/geoffreylean/100053276/stabd-by-for-the-greenest-leader-ever-whichever-miliband-wins/

OK, so the race between the Milibands is tightening, with a poll today suggesting that Ed may squeeze out his brother with second preference votes. But many environmentalists are sanguine about the result, whichever wins – for either will be far the greenest Labour leader yet.

Curiously, David Cameron is partly responsible. For David Miliband – who had shown little sign of green sympathies as the head of the Downing Street policy unit during Tony Blair’s first term – turned noticeably more verdant after the Prime Minister won his party’s leadership and espoused green issues as a way of making his party electable again. Indeed the two men first met socially as one entered, and the other left, a Friends of the Earth party.
The elder Miliband became environment secretary shortly afterwards and vigorously took up climate change as an issue, doing much to bring it into the heart of his government’s policy making. He proposed strong measures to bring down carbon dioxide emissions at home, even suggesting that everyone should have their own quota which could be traded so that those who used less (often the poor) could make money by selling part to those who wished to emit more than their allowance.
His younger brother was, of course, the first head of the newly created Department of Energy and Climate Change and also immediately set out to make a difference. He abruptly switched from his predecessor’s pro-coal policies, clamping down on new power stations fired with the fuel. And he was one of the very few heroes of Copenhagen, conducting the negotiations with real commitment, and saving the summit from complete collapse with a crucial intervention in the fraught early hours of its last morning.
Both Milibands have continued their commitment after moving on, and thus Labour seems bound to have its first green leader. Neil Kinnock, like his predecessors,  showed little interest in the environment. Tony Blair did make global warming one of his international foci, but did virtually nothing about it where it mattered, at home: carbon emissions increased during his premiership. And Gordon Brown, with no instinctive sympathy for green issues, only took climate change up late, through he did lead the unsuccessful international drive to get a breakthrough in the Danish capital.
The greening of Labour is likely to bring things full circle, by putting pressure on David Cameron to live up to his promise to lead the ‘greenest government ever’, and to expose the less enthusiastic Nick Clegg if he strays from the Liberal Democrats traditional commitment to environmental concerns.
But greens should not get too excited, at least for now. For though both Milibands have strong records on climate change, it is far less clear that they care about other environmental issues – such as increasing exposure to harmful chemicals, the drive for GM crops and foods, or damage to wildlife and landscape. The Government also shows few signs of concern about  them  either – particularly over what happens in rural Britain. It would be a truly tragic if a consensus for action on climate change, however important, led to these other pressing problems being ignored.