Shouldn’t we be tackling other issues, such as Aids, biodiversity and poverty, which will give us more ‘bang for our bucks’.

Global warming is the most serious of all the problems facing mankind and therefore deserves the highest priority response now. Although the future is uncertain, global warming is practically certain to happen and we cannot afford to ignore it.

This question reveals a flawed view of the potential seriousness of the impact of climate change on human health and development, and on biodiversity. Climate change is already making the poorest poorer in developing countries and in the future is the greatest threat to economic development both here and abroad. Regional and international conflicts caused or made worse by climate change threaten the very existence of civilisation. Even the viability of the human race, at least in its current numbers, may be threatened by the end of the 21st century. In addition, the rapid poleward migration of the climatic and vegetation zones and drastic decreases in productivity of the oceans, and of many habitats on land, mean that climate change has been rated, above habitat destruction by man, pollution, over exploitation, and the effects of invasive species, as the greatest threat to biodiversity.

Even if there is some uncertainty about its exact scale and impact can we afford to take the risk of ignoring climate change?