Around the middle of 2011 the world population clocks tell us that there will be 7 billion people on earth; that is 7,000,000,000 chemical engines requiring a minimum of 2,000 calories a day in food to stave off hunger.
The calorific value to our digestive systems of rice and wheat, the staple starches for most of us, is around 340 per 100g. If we only ate cereals to supply our daily calorific needs the gents would get through 290 kg and the ladies 214 kg in a year.
So we need 1.76 million every day if we were all vegetarians. Of course many of us enjoy meat. The efficiency of the energy transfer from plant to livestock to us means we need roughly three times the plant calories to provide animal protein.
Round off some numbers and ratios for the meat eaters and each and every day the agricultural land must produce the equivalent of 3 million metric tons of usable grain; over a billion tons every year.
Continue reading “Food Security – How Will We Grow Enough Food?”