Humans are a tough and adaptable species. People live on the equator and in the Arctic, in the desert and in the rainforest. We survived the ice ages with primitive technologies. The idea that climate change poses an existential threat to humankind is laughable.

Climate change will have consequences, of course. Since different plants and animals thrive in different climates, it will affect natural ecosystems and agriculture. Warmer and wetter weather will advance the spread of tropical diseases. Seas will rise, putting pressure on all that lives on the coast. These impacts sound alarming but they need to be put in perspective before we draw conclusions about policy.

According to yesterday’s[FOR ONLINE: MONDAY’S ] report by the Intergovernmental Panel on Climate Change, a further warming of 2C could cause losses equivalent to 0.2-2 per cent of world gross domestic product. On current trends, that level of warming would happen some time in the second half of the 21st century. In other words, half a century of climate change is about as bad as losing one year of economic growth.