Friday, July 03, 2009

peak oil and world food supplies


Countercurrents | he present population of the Earth is about 7 billion, but there is no point in being more specific, since the number is increasing daily. Nevertheless, 7 billion should be a large enough number to make us seriously consider the consequences. (What other large mammal can be found in such numbers?) When I was born, in 1949, there were less than 3 billion, and it amazes me that this jump is rarely regarded as significant. These 7 billion people in turn live on only about 29 percent of the surface of the Earth, i.e. on dry land, which is about 148 million square kilometers.

Of that 148 million square kilometers, the arable portion, as I said, is only about 10 percent, or 15 million square kilometers. If we divide that 15 million square kilometers into the present figure for human population, we arrive at a ratio of about 470 people per square kilometer of arable land.

Is that last ratio a matter for concern? I would think so. A hard-working (i.e. farming) adult burns about 2 million kilocalories (“calories”) per year. The food energy from Pimentel’s hectare of corn is about 7 million kilocalories. Under primitive conditions, then, 1 hectare of corn would support only 3 or 4 people — or, in other words, 1 square kilometer would support 300 or 400 people. And all of these are ideal numbers; we are assuming that all resources are distributed rationally and equitably. (We are also assuming no increase in population, but famine and the attendant decrease in fertility will take care of that matter very soon.) Even if every inch of our planet’s “arable portion” were devoted to the raising of corn or other useful crops, we would have trouble squeezing in those 470 people mentioned in the previous paragraph.

Given such figures, I have little patience with writers who sprinkle the words “alternative,” “sustainable,” and “transition” over every page. Simple arithmetic is all that is needed to show that such a lexicon is unsuitable.

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