Biology Comics

Cornucopians and Malthusians

In 1980 Paul Ehrlich, a biologist (author of The Population Bomb), along with his colleagues the physicists John Harte and John Holdren, bet the economist Julian Simon on the future price of metals. Ehrlich bet the prices would increase as the better ores (those more accessible, with a higher metal content) were used up. Simon bet that metals would become cheaper and cheaper.

Simon won. In 1990 the prices of all five metals (copper, chromium, nickel, tin, tungsten) were lower.

While ores were poorer, processing methods became more efficient and the energy needed for processing got cheaper. The rise in metals prices (up to 1975) stimulated substitution of cheaper materials (as the use of plastic pipe instead of copper), which reduced demand for metals and kept their prices down (they had to compete).

Economics focuses on the human world. It teaches that the best use for resources is to exploit them as quickly as possible to economic extinction, then invest the profit in something else. As the resource becomes more scarce (and expensive) people will find alternatives and the human world will not suffer.

Malthusians point out that there is only so much of any resource (fresh water, ocean fish, fertile farmland, unpolluted air) and when they are gone what will we do. Some will be hard to substitute for.

Don’t worry, say the Malthusians—harvest the ocean for a tasty algal soup; adjust the climate to where we like it. If all else fails, we’re off to other worlds!

In the early nineteenth century Malthus’ concern was that population (which has the potential to grow geometrically) would always outgrow the supply of food (which grows slowly if at all). (The idea that animals produce far more young than can survive is one of the bases of evolution.) But at the time Malthus wrote the exploitation of fossil fuels was beginning. Fossil fuels let people build railroads to open up new farmland, ship food in steam powered steel ships all over the world, manufacture fertilizers, trawl distant seas. Over the next century and a half population grew by several times while world output (food and stuff) grew by several tens of times. Many more people became a lot more prosperous (even if some of them remain as poor as before). We could feed all those people a healthy diet even now, if food were fairly distributed.

So who’s right? Ehrlich? Simon? Both?

Simon refused to take a later bet Ehrlich proposed (his partner this time was the climatologist Stephen Schneider) in which Ehrlich focused on the resources themselves—the amount of fertile farmland per person, the extent of moist tropical forests, the global temperature, the number of species of plants and animals. Simon wouldn’t take the bet because he said that the degradation of the planet didn’t matter. Less farmland would be made up through fertilizer, or by producing food in other ways. The human habitat (the virtual world maintained by fossil fuels) would continue to improve. He used the analogy of the Olympics. While Ehrlich was betting the track would be worse, Simon was betting the times of the athletes would be better.

John Tierney, a journalist who writes a contrarian column in the Science Times of The New York Times recently described a bet with an oil expert, Matthew Simmons. In 2005 Simmons bet Tierney and his partner Rita Simon, Julian Simon’s widow, $5000 that the price of oil would average $200 or more in 2005 dollars in 2010. The price of oil rose to $145 by the summer of 2008 but fell with the global recession in the fall of 2008 to $50. The average price in 2010 was about $80. So again the cornucopians won (this time by chance).

Human affairs, like changes in climate, are unpredictable. I would bet Tierney that the level of carbon dioxide in the atmosphere in October 2015 measured from the Mauna Loa Observatory in Hawaii will be 398 ppmv or greater; that is, that carbon dioxide will continue to rise at 2 ppmv per year. Tierney, like Bjorn Lomborg, the skeptical environmentalist, thinks the effect of manmade carbon dioxide on climate will be minimal. (I could bet that one year between 2011 and 2015 will be either warmer or wetter, or both, than any since reliable measurements started in the 1880s.) Simon wouldn’t have taken my bet, because he wouldn’t have thought climatic conditions a matter of his concern. Human welfare was his concern, something that modern economies let prosper apart from nature.

I find it difficult to understand that the cornucopians feel no regret for the changes I see taking place all around me (collapsing songbird populations; strange fish in the rivers; butterflies, birds and fish moving north; lakes that don’t freeze; suburbs marching over the hills); or consider matters like terrible agricultural and forestry practices, acidifying seas, tropical forests going up in smoke or melting glaciers nothing to worry about.

I think all these (and related) things will affect the human world. I think the cornucopians are out of their minds. But they are likely to be correct up about our ability to take care of the human world, right up to the very end.

Up to the edge of the cliff.

Last year (2010) was the wettest in the historical record and tied 2005 as the hottest. I think we are seeing the future now.