It is indisputable that human combustion of fossil fuels for energy is causing global climate change that threatens the very survival of our civilization. It is equally indisputable that our civilization is dependent upon cheap, reliable, and widely distributed energy for both mobile and stationary utilization. The obvious conclusion would be to decrease our reliance upon fossil fuels, and to seek energy from alternate sources. But neither solution is as simple, nor effective, as it appears.
Conservation of resources is a laudable objective. While consumer spending is an important component of the economy, conservation of natural resources is plain good sense, and if done properly is good business. However, conservation and a reduction in the emission of greenhouse gases will not reduce global warming nor even reduce the increase of global warming. All that conservation can accomplish is a reduction in how rapidly global warming will increase. As shown in the carbon dioxide article, even if we reduce CO2 emissions to 1990 levels, approximately a 30% reduction, we would still be increasing the amount of CO2 in the atmosphere by about 5,500,000,000 metric tons per year. And as also shown in the carbon dioxide article if we could manage to eliminate CO2 emissions global, temperatures would continue to increase until stabilizing at some higher level in a few centuries.
Hydro, nuclear, solar and wind are currently the only alternate, non-carbon fuels that appear viable and each has severe limitations. Even with 50 years of experience with nuclear power, we do not have a means of disposing of the highly radioactive waste products, safety concerns remain, and depending upon whom is doing the calculating, economic viability remains questionable. While nuclear power has been utilized to power surface vessels and submarines, in addition to producing electricity, its adaptation to powering surface vehicles or aircraft is highly speculative.
Hydro and wind are suited only to electricity production, and facilities are restricted to specific locations. Solar can produce both heat and electricity, but again, installations are relatively restricted to high-solar location, and the energy source is diffuse, lowering efficiency. Interestingly, hydro, wind and solar are also sensitive to climate change.
There is currently high interest in "biofuels", especially the fermentation of high sugar content plants, primarily corn and sugar cane, with ethyl or butyl alcohol as the end product. These fuels are being promoted both as a means of achieving energy independence and to reduce greenhouse emissions. But any such claims need to be carefully examined and the total energy costs of production including natural gas based fertilizers, and distribution taken into account, as well as the impact of any land use change and crop replacement. For example, a recently proposed ethanol plant in Chesapeake, Virginia, would consume twice the total annual production of corn in the state of Virgina and would rely on imports from South America and the midwest for the bulk of its annual requirement of 80 million bushels of corn (The Associated Press. July 30, 2007, 11:29pm. Imported corn would fuel ethanol plant in Va.) It is difficult to see how such a scheme could produce ethanol with more energy than contained in the fossil fuels used to produce the corn, ship it to Chesapeake, and distribute it to consumers; nor, how importing foreign corn would make us more energy independent.
In the evaluation of alternate energies, we need a means of measuring the energy/carbon costs and benefits of the entire production, distribution, operation and disposal life-cycle. For example, the heavy batteries of hybrid vehicles use fossil fuels in their manufacture and delivery to consumers. These exotic nickel-metal hydride batteries will eventually need replacement and special disposal procedures. We have not yet faced the widespread replacement of the first generation of hybrids, but there are estimates that the process will negate any energy and emission benefits achieved during the operation of the vehicle. Likewise, the disposal of spent uranium from nuclear power plants remains unsolved, and thus an unknown energy/carbon cost.
Fluorescent light bulbs consume considerably less electricity per unit of light than incandescent bulbs. However, fluorescent bulbs contain mercury, a hazardous substance, and legally require special disposal procedures to recover the mercury. Increasingly popular Compact Fluorescent Lamps are commonly manufactured in China, a country notorious for "dirty" power production and high CO2 emissions. The carbon cost of manufacture and of shipping from China to the consumer must be included in any consideration of energy "savings". Again, we need a system of total life-cycle carbon accounting to make an accurate and honest appraisal of any purported energy savings.
Can we meet our global energy needs, while eliminating the emission of greenhouse gases, or Are We Toast?