30,000 m people in 100 years

Press, Volume CXI, Issue 32708, 10 September 1971, Page 11

30,000 m people in 100 years

(By

JOHN H. FREMLIN)

LONDON. The twentieth century will be recognised by historians as the critical period in the development of the human race. Not because of the nuclear bomb or of radio communications, but because in this century we have learned how to multiply without natural limit.

■ Like all other animals, we i used to be limited in many I ways. We were eaten by the . big cats; we starved'for lack ; of food; we died from disease. First, by a combination of ; co-operation and weapons, we got rid of the predators as a ■ serious hazard. This could well have been the take-off point for the human race. For hundreds of millen- ' mams we fought each other for food and territory, which developed our brains but n'ot

our instinct for international co-operation. The invention of agriculture and the overcrowded cities which it made possible made disease more important as a limit than either food or fighting. Disease has been reduced to ineffectiveness by drains, immunisation and antibiotics. Scientific agricul-

ture has enabled food output to grow with the population —although unevenly. While continued multiplication would undoubtedly lead to catastrophe, there need never be a world shortage of food. I am perfectly aware that there are already large populations suffering serious and chronic shortage of food but this is not necessary; it is

1 because those with the knowhow and money do not have the need while those who have the need have neither the know-how nor the money. The world population is doubling every 34 years. In a century we should reach some 30,000 m. I do not know whether the green revolution could cope with that but if we must multiply it gives us time to prepare alternatives. These are technically easy, given time and money, but require complete ruthlessness in destroying all inedible living things, and even the motor car, to grow human food. Then we could at each point on the planet grow the plants which most efficiently used the energy of sunlight—the basic income on which the entire life of the world is at present based. We know the maximum efficiency , with which plants can use this energy and can calculate the maximum amount of food; that the world could produce. : If we wasted nothing on meat i nor milk this could feed some three million million people. :

■ As we are going, we should i reach this in about 330 years. [ No significant human activity could be permitted i above ground, as this would , keep the sun off the land , plants. Cities would have to . be built floating in the sea—50ft down so as not to keep ' the sun off the edible oceanic algae. Beyond this, sun-based agriculture could not take us, neglecting the 60 years or so that might be gained by setting up big satellite mirrors to reflect sunlight back on to the night side of the earth. Already, however, we are producing the most vital foods in factories without any use of sunlight whatever. In Grangemouth, Scotland, 4000 tons of protein a , year are being produced from i oil waste, using a succession , of bacteria and yeasts. Carbohydrates and fats we can, already make by direct | synthesis. This will soon be cheaper than agriculture. Atomic power and chemical ! raw materials will be more i

1 than enough. We shall come to a new limit long before ’ these run out. In 800 years time, we [ should reach 100 people per * square yard over the whole 1 planet. Dispersed in 20001 storey buildings there would ■ still be plenty of room, and 1 plenty or food and oxygen to ■ breathe could be obtained from a mixture of 98 per cent I human excreta (including the • carbon dioxide we breathe 1 out) and'2 per cent of freshly ’ extracted material. The limit 1 would be fixed by the prob- ■ lem of getting rid of the heat given off by our own bodies, together with the heat produced by the essential machinery. At 100 people per square yard the roof over the entire planet would have to run at 8 bright white heat. One or two more doublings and it would melt. I would prefer that we should limit our birth-rate before we even approach this end. But if we don’t, we shan’t starve. We should die with our bellies full.

Professor John H. Fremlin is a British physicist. The article comes from the “New York Times” Special Feature Service, through N.Z.P.A.