The latest UN talks on climate change convey a sense of broad international support for action on tackling greenhouse-gas emissions, as do the recent spate of national and regional plans for emissions reductions. But a structure needs to be put in place to unify the current piecemeal approach to mitigation.

Convened by Secretary-General Ban Ki-Moon from late July to early August, the UN General Assembly's first plenary session devoted to climate change paved the way for further high-level talks on 24 September, themselves a prelude to negotiations at the end of the year, when the details of a post-Kyoto pact will be wrangled over in Bali.

Not one of the 100 nations represented at the UN assembly questioned the scientific consensus on this position, according to Yvo de Boer, Executive Secretary of the UN Framework Convention on Climate Change. Furthermore, during the talks many developing nations, which are not required to cut emissions under Kyoto, presented their national initiatives on climate change. Both China and Mexico recently announced climate change action plans, and India is making moves in the same direction, having recently established a special Council on Climate Change. Similar schemes have been put in place over the past two years by various US states and cities, frustrated by their government having not yet ratified the Kyoto Protocol.

Although each of these initiatives shows a willingness to act on mitigating further warming, they also represent the ad-hoc and potentially redundant arrangements that are developing in the absence of a formalized system to re-evaluate targets and timeframes on emissions reductions in line with advances in our scientific understanding of climate change.

Meanwhile, the UN high-level talks planned in September, like many of the previous climate talks this year, lack measurable objectives.. Even the talks in Bali could, at worst, end without an agreement on how to move forward, and at best, will agree a roadmap for further negotiations until 2009. Change doesn't happen overnight, but time isn't on our side. Speaking at the UN summit, de Boer noted that research from the International Energy Agency shows that if we make the investments necessary to meet international energy demands without accounting for climate change in the technologies used, global greenhouse-gas emissions could increase by as much as 50% within 20–25 years.

If a strict timeframe of targets to achieve aggressive emissions reductions is not agreed by the end of the year in Bali, we risk having to rely too heavily on being able to adapt to considerable future climate change rather than taking the necessary steps to avoid it.