Climate change is fast becoming the key issue confronting the world. Sure, we don’t really feel the difference from one year to the next. Believe me, it’s there. From a hundred years before I was born, I am told the world is today on average at least 10°C warmer. Make no mistake. Ever since the mid-19th century, the deliberate burning of fossil fuels (mainly coal) then produced 2 billion tonnes of carbon dioxide (CO2). By mid-1950s, emissions were three times more; today, twenty times.

This reflected a period of wars, technological change, expanding global trade and a staggering rise in population as well as the creation of enormous wealth – all stemming from the combustion of billions of tonnes of fossil fuel to produce industrial power & electricity. Nitrogen-based explosives & fertilisers (which fossil fuels made cheap & plentiful) transformed warfare, mining & farming. Oil refineries turned out raw materials for plastics. The felling of trees made everyday life so much more comfortable. The last time the Earth had a CO2 level similar to today’s, it was about 30°C warmer on average. Greenland hills were then green; parts of Antarctica were fringed with forests; the water now frozen over landscapes was in the oceans, providing sea levels 20ms higher than today. Proof that humans were warming the Earth took time. Today, CO2 is not the only greenhouse gas. Methane & nitrous oxide also trap heat. So does water vapour. They each amplify the effects of the others. Complexities abound as the resulting “aerosols” also warm the atmosphere. Their dynamics resulted sometimes in El Nino events, which raise surface temperatures. As I see it, the “science” is today indisputable. The effects of human activity and industry were not statistically significant until the 1980s. There are no legitimate doubts today.