"The Road to Copenhagen” may sound like the title of a clunky old Bob Hope film, but it’s actually an entertainment-free document from the Government mapping out “the case for an ambitious international agreement on climate change”.

There’s nothing new in this manifesto published yesterday, but it’s as powerful a piece of government advocacy on climate change as any I’ve seen — providing further compelling evidence that Ed Miliband’s role as Secretary of State for Energy and Climate Change is beginning to deliver the goods.

There are now less than six months to go before world leaders gather in Copenhagen to seek a new global agreement to replace the Kyoto Protocol. It’s hard to exaggerate the significance of the Copenhagen conference. If climate change is indeed “the greatest single challenge the world now faces” (as Tony Blair describes it), then getting a new agreement in place as soon as possible is absolutely fundamental.

This is a road the UK has been travelling down for many years. In 1988 Mrs Thatcher was the first world leader to focus attention on climate change. When Labour was elected in 1997, both Mr Blair and John Prescott, the Deputy Prime Minister, immediately took the lead in arguing the case for urgent change, and no nation has done more since then to keep international negotiations moving forward. Unfortunately, even the silver-tongued Mr Blair could not break down George Bush’s obdurate hostility to addressing climate change, and the world will pay a heavy price for those eight wasted years in the White House.

While Gordon Brown does not share his predecessor’s personal enthusiasm for making a priority of climate policy, he has, nonetheless, encouraged David Miliband as Foreign Secretary, to maintain a proactive position for the UK in climate-change diplomacy. And in creating a new department — the Department for Energy and Climate Change — he has started to remove some of the blockages in Whitehall that meant that our domestic delivery on climate change has never matched the quality of our international leadership.

For all the plethora of new initiatives and statutes over the past ten years, our performance in achieving significant reductions in emissions of greenhouse gases has been mediocre. Emissions are falling, and the UK will meet its obligations to the Kyoto Protocol. But not by as much as the headline figures indicate once emissions from shipping and aviation (as well as emissions “embedded” in all the goods we import from countries such as China) are factored in.

Cross-government leadership has been poor. The Department for Transport has contributed nothing to the Government’s overall action plan. Despite Britain having the best renewable energy resource in Europe, there are only two countries (Malta and Luxembourg) that generate less electricity from renewables than we do; energy efficiency measures have been half-hearted and often ineffective. And the Government has consistently failed to “walk the talk” in terms of reducing emissions of greenhouse gases in the public sector.

But at long last, that is changing. The rhetoric in which we have always excelled is being grounded through the Climate Change Act and supporting measures.

The challenge now, for governments all around the world, is to narrow the gap between what the science is telling us and what voters are prepared to go along with — or are perceived to be prepared to go along with. As “The Road To Copenhagen” makes clear, the science of climate change leaves less and less room for manoeuvre. Indeed, there are now a growing number of scientists who believe that the consensus position so painfully negotiated by the Inter-Governmental Panel on Climate Change back in 2007 doesn’t reflect the speed and intensity of climate change.

But most ministers seem to be trapped in a 2000 time warp: they are still ludicrously fearful of the “Return of the Fuel Tax Protesters” and out of touch with the general public’s growing environmental awareness. If Jeremy Clarkson’s bombastic scepticism still carries more weight than the stark warnings of the Government’s Chief Scientific Adviser — or even of the saintly Sir David Attenborough — that may have more to do with the cowardly refusal of ministers to take on these sceptics directly than with the electorate’s unyielding ignorance or indifference.

In that respect, the British Government has got it easy in comparison to the new US Administration. Decades in reality-denying darkness, force-fed a diet of Fox News fantasy and neoliberal nonsense have left tens of millions of American citizens struggling to absorb even the basics of the unfolding science.

That explains the radically different reactions to the Waxman-Markey Bill going through Congress. Many environmental organisations are deeply disappointed at the compromises already made, accusing President Obama of having reneged on all his election promises about climate change — not least on the commitment to base US policy on the science, not on the grungy, pork-barrelled politics that still dominates the US system. In their eyes, the overall outcome (a 17 per cent reduction in greenhouse gases by 2020, based on 2005 levels) is forlornly inadequate given that the science tells us that at least a 40 per cent reduction by 2020 is the minimum that’s required in the developed world.

By contrast, environmental pragmatists argue that it will be a near-miracle if the Bill passes through both the House of Representatives and the Senate — given where the US, its politicians and its voters are coming from. And I tend to agree with them — not least because a deal in the US opens up the possibility of a deal between the US and China, and without that deal, there will be no (serious) deal done in Copenhagen.

This is just one of the many potential blockages along the road — and through its climate diplomacy, our Government is contributing as much as any to secure as smooth a journey as possible.

Jonathon Porritt is founder director of Forum for the Future, chairman of the UK Sustainable Development Commission and author of Living Within Our Means

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