“The UCL Lancet Commission on climate change and health (May 16, p 1693) concludes: ‘Climate change is the biggest global health threat of the 21st century.’ In this report, the authors emphasise not only the immediacy and gravity of this threat, but also the directness: while the poorest in the world will be the first affected, none will be spared. The escalating carbon footprint of the developed world has led to the present situation, but the rapid impact on developing countries such as the encroaching deserts in Africa is the immediate price.

“This is one reason why doctors must take a lead in speaking out. Another is that there are important co-benefits of tackling climate change for those with long-term conditions in the developed world, such as those that come from more exercise with less use of cars and dietary change with reduced meat consumption. In December of this year, world governments meet in Copenhagen, Denmark, to negotiate a new UN Framework Convention on Climate Change. There is a real danger that politicians will be indecisive, especially in such turbulent economic times as these. Should their response be weak, the results for international health could be catastrophic. Doctors are still seen as respected and independent, largely trusted by their patients and the societies in which they practise. As leaders of physicians across many countries, we call on doctors to demand that their politicians listen to the clear facts that have been identified in relation to climate change and act now to implement strategies that will benefit the health of communities worldwide.

“We declare that we have no conflicts of interest.”