A Step Farther Out Read Free Page B

clearly a high-energy enterprise. Even providing Mylar linings for traditional dung-smeared grain storage pits (animal dung is often the only waterproofing material available) requires high-energy technology.
    And in the West we waste land because we have land to waste; our agricultural technology produces surpluses.
    A hard-working person needs about 7000 large Calories, or 7 million gram-calories, per day. The sun delivers nearly 2 gram-calories per square centimeter per minute; assume about 10% of that gets through the atmosphere, and that the sun shines about five hours (300 minutes) per day on the average. Further assume that our crops are about 1% efficient in converting sunlight to edible energy. Simple multiplication shows that a patch 35 meters on a side will feed a man—about a quarter of an acre.
    Granted, that's an unfair calculation; but it isn't that far off from reality. My greenhouse, 2.5 meters on a side, can produce enormous quantities in hydroponics tanks, and there's no energy wasted in transportation and distribution of the food. I do use electricity to run the pumps, but that could be done, if necessary, by hand labor.
    In Japan and in some of the oil-rich sheikdoms, hydroponics farming has been carried to fantastic lengths; acres of covered territory, with vegetables growing in the sandy deserts of Abu Dhabi, watered by desalinated seawater.
    This is high-technology, of course. The chemical nutrients needed in my greenhouse take a lot of energy to manufacture. The greenhouse itself is made of aluminum tubing and Mylar plastic reinforced with nylon strands. The piping and trays are plastic. All high-technology items, as are the fungicides I use, and even the water-testing kit that lets me balance off the pH in the nutrients.
    Given the energy we can produce food. I think few would deny that. It is true enough that if the average Indian farmer could reach the productivity per acre achieved by the Japanese peasant of the 12th Century, India would have few food problems; but he's not likely to get there without industrial help (at the very least a television and satellite-relayed instructions). Moreover, the Japanese have had to move far ahead of their 12th Century output levels.
    But I hope the point is obvious. Given sufficient energy, we have the technology to produce food. We may not have the energy; but famine is not a primary problem. With sufficient levels of industrialization we could even feed cities from greenhouses on the roofs of city buildings: if 1% of New York City were covered with greenhouses, they could feed 10% of the New York population. One percent of the surface area of Los Angeles would feed 1/3 that city's population.
    We haven't even looked at the potential of the seas. True, our fish catches have about peaked out and may be declining—but man was never meant to be a hunter-gatherer.
    Our exploitation of the seas is on a par with our use of land before we learned about agriculture and domestication of animals.
    Sea-farming is a technology in its infancy; but experiments at St. Croix in the Virgin Islands (supported in part by the Vaughn Foundation which supported research for this book) show that fantastic levels of food production per acre can be achieved. The St. Croix research consisted of pumping cold nutrient-rich water from the sea bottom into pens where sunlight could energize plant growth; food harvested was shellfish and the like.
    Other sea-farming enterprises in France and Britain show similar results. Selective fertilization of sea areas can increase sea-plant growth by orders of magnitude; one then introduces edible creatures which thrive on the plants. The production levels are again astounding, ten times what a given land area can produce.
    Once again these are high-technology enterprises; but there is nothing far-out about them.
    Clearly food production per se is not going to be a limit to growth for a very long time. Food production can only be limited by an