Peak Food and Population Overshoot
by John Rawlins
John Rawlins has a B.S. in physics and a Ph.D. in nuclear physics. He retired in 1995 from the Westinghouse Hanford Co. at the Hanford site in Eastern Washington. Currently, he teaches physics and astronomy at Whatcom Community College.
Part 3
A wall chart in the Whatcom Community College physics lab shows the historical (and projected future) curve of oil extraction along with other geo-petroleum data. There is also a curve on the chart that, because of its color, is difficult to see and is easy to overlook entirely. When I ask a student in my energy class to notice it and tell everyone else what the label on the curve is, there’s always a moment of realization and the dawning of a major future problem in a world with declining oil availability. The nearly invisible curve shows world population versus time, and the population curve correlates perfectly with the oil extraction rate curve.
Before oil (and natural gas) humans used manual labor to grow food, and the amount of food determines an upper limit on population. The large-scale, increasing use of oil and natural gas in the industrial world’s food-growing enterprise has meant ever-increasing quantities of food — until now. Therefore, population increase over the past 150 years correlates very well with oil extraction.
By far the largest population increase in the history of humans occurred in the 20th century, and the resources making that possible were oil and natural gas. Now that we face a very near-term decline in both of these resources, it is time to start planning how we will continue to feed a population of over 6 billion humans. In about 100 years, when oil and gas are essentially gone, will it even be possible to provide enough food for six to 10 times as many people as populated the planet before oil and gas? This article will summarize what I’ve learned during the past three years on this subject, which still troubles me far more than anything else related to peak oil/gas and climate change. This is a challenging topic to think about, because I continue trying to find reason for hope when the logic seems to provide little justification for it. Still, we can learn from our past, and there are some seeds for food-growing ideas there.
Humans Used Technology Breakthroughs to Increase Food Supply and Population
In my energy class students think about a one-page table showing a summary of the history of human population increases and the technological breakthroughs that enabled those increases. From a few million years B.C. to around 10,000 B.C. world population was likely in the few million range, and the technologies that were important in that period included use of fire, tool-making, spears, and bow-and-arrow. During this period, humans were in hunter-gatherer-scavenger groups. They ate mostly what nature provided: fruits, nuts, berries and meat from other mammals. During this, the longest time period on the list, remember that a few million humans were matched with the available natural food supply.
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Whatever the answer to Earth’s carrying capacity turns out to be, we must learn very, very soon about lower-energy methods for food production and start implementing them as rapidly as possible. One interesting case study comes from Cuba, which lost much of its oil supply (from Russia) when the former Soviet Union collapsed. Following some scary years amidst fear of wide-spread starvation, most Cubans are now involved in food production in fields and yards, and the practice of food growing advocated by permaculture activists has taken root in Cuba. One of the fundamental ideas of permaculture is to plant food species that require less human energy than the conventional intensively managed vegetable garden. The concept of forest gardens — involving fruit and nut trees, combined with perennial understory plants such as berries and food-producing groundcover — evolved from permaculture ideas. In essence, such forest gardens are a dense source of food for the future’s hunters and gatherers. Even today’s urban and suburban dwellers can participate by replacing their grassy lawns with perennial food crops. A future article will describe in more detail the business of forest gardening and permaculture.
http://www.whatcomwatch.org/php/WW_open.php?id=765