“Baffling” and “irresponsible” were some of the words used to describe the British government’s decision earlier this year to leave climate change off the agenda for the 2013 G8 Summit. When the leaders of Canada, France, Germany, Italy, Japan, Russia, USA and UK meet at a golf resort in Lough Erne in Northern Ireland on 17 and 18 June, they will instead focus on a slimmed down agenda consisting of trade, tax and transparency. Climate change, alongside poverty eradication, may still end up being discussed in the margins of the meeting. But with the conflict in Syria set to dominate bilateral conversations particularly between David Cameron and Barack Obama, the G8 is unlikely to inject fresh momentum into the current efforts to reach a global climate agreement by 2015.

To be sure, the three T’s of the Lough Erne agenda are worthy topics for global discussion, and priorities inevitably change every time the G8 Presidency is passed on. The British Prime Minister has invested considerable political capital in a deal on tax compliance and transparency, mindful of the gathering public storm over multinationals slashing their tax liabilities thanks to an abundant supply of legal loopholes and tax havens. But David Cameron’s decision not even to mention the climate change challenge in the official agenda has more than just ruffled environmentalists’ feathers. Both France and Germany are said to have tried but failed to get the British government to change its mind. They will struggle to make a difference at the meeting itself.

Some will interpret this as another sign that climate change is slipping down the global policy agenda. After the failed 2009 Copenhagen climate summit, which produced excitement and disappointment in equal measure, it was unsurprising that summit fatigue and political cynicism would drain international climate politics of the energy that had propelled it to the top of the agenda in previous years. And the global economic crisis and fiscal tightening in the OECD further reduced the political space for a renewed push on international climate commitments. Despite its longstanding claim to a leadership role in climate politics, the UK government now seems content to let others do the heavy lifting in support of a new global climate accord.

And yet, it may turn out to be a grave political miscalculation to follow rather than set the trend in climate politics. With just over two years left before the 2015 climate conference in Paris, which is supposed to finalise a new climate agreement, this year and next will be crucial in narrowing the main differences between the major climate powers. In the past, G8 meetings offered an opportunity to reconcile transatlantic differences over climate policy before the EU and US engage with other major emitters in the UN climate forum. Having re-engaged in climate multilateralism under President Obama, the US is now in a much better position to agree to some form of international emission reduction targets, particularly so as the shale gas boom and efficiency gains have led to a recent reduction in America’s greenhouse gas emissions.

At the same time, China’s government has signalled that it is increasingly serious about tackling the country’s rapidly expanding carbon footprint. Having previously agreed to reduce the emission intensity of its economic growth model, some government officials are now suggesting that China might agree to an absolute cap on future emissions. If this were to become the basis for a comprehensive emission reduction agreement involving all major emitters, it may well turn out to be the most significant breakthrough in two decades of climate talks.

Of course, major hurdles need to be crossed if we are to get to a meaningful 2015 agreement, and optimism remains a rare commodity in climate politics. Current emission trends, if unchecked, will make it ever more difficult for the world to stay within a 2 degree Celsius warming scenario. Preventing disastrous climate disruption presents the world with arguably the most complex collective action problem. In this sense, a mere G8 declaration on climate change would be little more than a minor signpost on a long and arduous journey. But political momentum is desperately needed in the climate talks, and every opportunity has to be grabbed to forge an international consensus on climate mitigation.

Which begs the question of what has happened to the UK’s much praised leadership role in climate politics. There can be no doubt that the Department of Energy and Climate Change’s (DECC) climate team are working on a 2015 agreement as tirelessly as in the past. But the perception is hardening that the Prime Minister has lost faith in his own promise to lead the ‘greenest government ever’. Environmental policy, once part of the modernising agenda of Cameron’s team, has been pushed aside by more traditional Conservative Party concerns over Europe, immigration and the economy. That the Tory right is making inroads into the coalition government’s environmental agenda became all too clear when Cameron appointed Owen Paterson to the post of Secretary of State for Environment, Food and Rural Affairs in September 2012. Known for his climate sceptic views and opposition to wind farms, Paterson’s most recent pronouncements on global temperature trends have put him again firmly at odds with the scientific community.

By excluding climate change from the official G8 agenda, Cameron has missed an opportunity to set the record straight on his declared ambition for global climate leadership. As so often in G8 gatherings, domestic politics is intruding into the summit agenda. If the meeting in Northern Ireland turns out to be an empty diplomatic exercise, not much will have been lost. However, if the international negotiations on a 2015 climate agreement were to succeed, this will have been achieved despite, not because of, Cameron’s G8 efforts.