Leading article: Climate change demands better political leadership

We have reached the halfway point in the Copenhagen climate change negotiations and the prospects for success remain uncertain.

Yesterday a European Union summit agreed an early package of aid to help developing nations adapt to the immediate impacts of climate change. But there was also a split over the proposal to increase the EU's emissions reduction target for 2020. Eastern European nations, particularly those with a legacy of heavy industry such as Poland, are already wary of the implications of hitting the present targets.

And even if agreement is reached at Copenhagen, there are doubts over whether the targets and timetable will be sufficiently rigorous to forestall runaway planetary warming. There is a feeling that national leaders are failing to be sufficiently radical in the negotiating chamber.

One reason for this is an absence of popular pressure for an ambitious deal. Polls suggest that public opinion around the world, though it seems to be coming round to the need for action, has still not moved decisively behind global efforts to mitigate climate change. This can partly be explained by lingering perceptions of uncertainty in the science, exacerbated by the recent scandal over emails from climate scientists at the University of East Anglia. But it also stems from a failure of leadership by politicians themselves. They need to do a better job of explaining to their populations that (despite those dubious emails) the science underpinning climate change is extremely robust. And they need to do this without implying that those yet to be convinced are ignoramuses, or "flat earthers".

Politicians have allowed the political debate to become dominated by alarm over the consequences of temperature rises and fear over the costs that mitigation efforts will entail. Leaders should be doing more to explain the economic opportunities that are presented by the necessary switch to low-carbon growth. For nations such as Britain it should mean that, instead of importing an increasing share of our energy from abroad in the form of oil and gas from Russia and the Middle East, we can generate it at home through renewables. That will mean domestic jobs and profits, both of which are sorely needed.

This does not mean politicians should skirt over the potentially catastrophic consequences of warming, nor the costs that early action is going to demand in the form of higher energy prices and certain taxes. But it does mean that they need to paint a much fuller picture to their electorates, laying out the gain as well as the pain that lies ahead. This exercise in leadership needs to happen urgently and in parallel with efforts to secure an international agreement on limiting emissions.

A global deal is necessary to tackle global warming, but such an agreement will only be the first step. Then comes the even more difficult task of implementing the measures necessary to reduce emissions. A market-based system in which a price is put on carbon and the private sector comes up with new ways of powering economic growth is certainly the right framework. But the debate about whether a cap and trade system, or a simpler carbon tax, would be better at achieving that is far from settled. Certainly there should be no dogmatism about how to go about achieving this. What matters is what works. Yet first world leaders need to come together in a historic agreement on the direction of travel. And that is where Copenhagen can – and must – deliver.