Many options--except for plastics?

Concerning peak oil production: Why do some people spend time trying to prove that the peak is far off? My feeling is that subconsciously this takes them off the hook; they do not need to act right away. And this allows them to label others by the pejorative term "catastrophists."

Contrariwise, the great amount of uncertainty is the frightening aspect of this problem. The worst scenario is just as likely as the best. The societies of industrialized nations are based on cheap transportation. If the peak is at hand and we do nothing, the lack of transportation will be one of the worst crises that humans have ever faced. Therefore the most important statement in the review on this subject was Robert Kaufmann's: "If the infrastructure for the alternative energy source is put in place before the peak arrives, the energy used to do so will have a relatively small impact on non-energy sectors. Conversely, if society waits until the peak, constructing the large infrastructure for the alternative fuel will siphon large amounts of energy from the non-energy sectors of the economy at the very time that the total supply and energy surplus from oil is shrinking. In short, society has to pay the costs for the transition. We can pay them now, while we have oil in the bank, or we can pay them later, when our oil bank account is emptying."

The only possible large-scale sources of energy are well known: coal, methane hydrates, solar, fission, and fusion. None of these is as convenient as petroleum, which is highly concentrated, cheap, and easy produce, transport, store, and use. All the others present serious difficulties. Fission is out of the question; it places an enormous burden on future generations. Fusion may be possible, but research must be increased immediately. The main problem may be construction of the enormous facilities for production of the electricity. Coal and methane hydrates are possible, but sequestering the carbon dioxide is absolutely necessary; global warming presents a great threat. Solar is a very large source of energy which gives very low pollution, but it is very diffuse. The superstructure will be enormous. Research and development of solar cells must be increased drastically, and steps toward distribution of trapped energy must be started right away. Electricity can be distributed via the power grid already in place. Some electricity can be stored in batteries, which can operate vehicles. Massive storage can only be achieved via production of hydrogen, by electrolysis of water. (Some research has been done on solar cells which give hydrogen and oxygen directly. These must be investigated further.) Distribution via the natural gas pipeline network may be possible, but hydrogen embrittlement may present great difficulties. Some gas can be stored in large gas storage tanks, or as liquid hydrogen. Because it boils at 20[degrees] Kelvin [20 Celsius degrees above absolute zero], insulation will be a difficult problem. Probably most of the hydrogen will be utilized in fuel cells. This is the much touted "hydrogen economy," which will not be a cake walk. Methane from methane hydrates can be distributed via the network of pipelines already in place. Storage as a gas is possible, just as with hydrogen. Liquid methane boils at 111[degrees] Kelvin, so less insulation will be needed. If used as a fuel in transportation, emission of carbon dioxide is still a problem.

Airplane travel may be impossible. On a volume basis hydrogen gives about one-fourth as much energy as petroleum, so fuel tanks will be four times as large. However, the main difficulty is the thick insulation needed for the liquid hydrogen. The mass of the liquid hydrogen is about 40 percent that of petroleum fuel, so there is some gain there. Liquid methane is possible, giving 80 percent of the fuel value of jet fuel. The mass of methane is about 80 percent that of jet fuel on a volume basis, so even though liquid methane will need about 70 percent as much insulation as hydrogen, the balance between mass of fuel and insulation is about the same for each.

Either coal, liquid hydrogen, or liquid methane will be suitable for ocean travel. We could change back to coal-fired steam engines. The amount of carbon dioxide may be acceptable. However, it might be wise to investigate the possible role of sailing vessels. With modern satellite viewing, ships could take advantage of the most advantageous winds and still avoid storms.

In all the discussions concerning the decrease in petroleum I have not yet seen mention of the passing of cheap plastics.

R. THOMAS MYERS

Stow, Ohio, U.S.A.