The Rational Optimist (P.S.)

by Matt Ridley

If the average yields of 1961 had still prevailed in 1998, then to feed six billion people would have required the ploughing of 7.9 billion acres, instead of the 3.7 billion acres actually ploughed in 1998: an extra area the size of South America minus Chile. And that’s optimistically assuming that yields would have remained at the same level in the newly cultivated land, taken from the rainforests, the swamps and the semi-deserts. If yields had not increased, therefore, rainforests would have been burnt, deserts irrigated, wetlands drained, tidal flats reclaimed, pastures ploughed – to a far greater extent than actually happened. To put it another way, today people farm (i.e., plough, crop or graze) just 38 per cent of the land area of the earth, whereas with 1961 yields they would have to farm 82 per cent to feed today’s population. Intensification has saved 44 per cent of this planet for wilderness. Intensification is the best thing that ever happened – from the environmental perspective. There are now over two billion acres of ‘secondary’ tropical rainforest, regrowing after farmers left for the cities, and it is already almost as rich in biodiversity as primary forest. That is because of intensive farming and urbanisation.