Electricity is clearly an essential pillar of our civilization. We now have to face basic questions: With increasing demand and dwindling energy sources, will there be enough electricity to supply our needs? Can our future electricity be generated without harmful effects to human health and planetary health?

The NH Sierran was fortunate to have found Dr. Arjun Makhijani, President and Senior Engineer of the Institute for Energy and Environmental Research, willing to address some of these questions. He is the principal author of the first ever assessment of the energy efficiency potential of the U.S. economy (1971) and has written widely on energy and environmental issues. In preparing these answers, he consulted with Dr. Brice Smith, Senior Scientist at IEER, who is working on a book on nuclear power and global warming.

Some environmentalists recently expressed the opinion that we may have to face up to the risks of nuclear power generation and its radioactive waste legacy as a lesser evil than burning fossil fuels. Please share your view on this topic.

There is now near universal agreement that climate change is by far the most severe environmental problem facing the world and that carbon dioxide is the chief among greenhouse gas driving it. Since nuclear power plants (including the associated infrastructure) have zero or low carbon dioxide emissions, some leading environmentalists also appear to be having second thoughts about their opposition to nuclear power. The nuclear industry is trying to use climate change as an opportunity to revive a moribund market with large governmental subsidies.

However, the main question is not whether nuclear power can be used to reduce carbon dioxide (CO2) emissions. There is no shortage of energy sources that have no or low CO2 emissions. The potential for wind-generated electricity in the 12 states down the spine of the United States (North Dakota to Texas, including Midwestern and Rocky Mountain states) is equal to two-and-a-half times the entire electricity generation of the United States.

Put another way, the energy potential there is roughly the same as the oil output of all the members of the Organization of Petroleum Exporting Countries (OPEC).

What is in short supply to address the problem is not energy sources but money. Therefore, the main question is: for a given amount of money, what approach to reducing CO2 emissions will minimize other costs and risks to society and to future generations? It is in answering this question that nuclear energy fails the test.

Please give us an overview of the percentages of U.S. and global electricity currently supplied by coal, oil, gas, nuclear, and renewables such as water, wind, solar.

Coal supplies 50 percent of US electricity, nuclear power about 20 percent; natural gas under 20 percent, hydropower about 7 percent, oil about 2 percent. Renewables other than hydro are just about 2 percent, mostly wind energy and some geothermal. Solar energy is very small, much less than one percent.

Globally, fossil fuels (mainly coal) supply about 64 percent of electricity, hydro and nuclear about 17 percent each, and renewables about 2 percent. It is important to remember that fuel use in sectors other than electricity is also responsible for CO2 emissions - notably transportation, heating in buildings, and fuel use in industry.

All energy sources have some impact - in this sense, the use of energy is like other issues. As a corollary, unlimited use of energy, like any other resource is neither possible nor sensible.

What is the potential for increasing efficiency?

The efficiency of use of energy in the United States and other industrialized countries is pathetically low - and it is even lower in developing countries. For instance, a typical high-efficiency gas-fired central heating furnace has an efficiency of less than 10 percent, when evaluated by strict physics criteria (the second law of thermodynamics). Electric resistance heating is even more inefficient. The average efficiency of electric lighting systems is about one percent - that is, only about one percent of the energy in the fuel used to generate the electricity comes out as visible light energy. The rest is wasted as heat either at the power plant or in the light bulb. Even high efficiency lamps have an efficiency of only about 3 percent. And much of the light is wasted too.

Passenger transportation efficiency is similarly dismal. The useful work done when a car weighing a ton-and-half transports one person weighing 150 or 200 pounds is less than one percent of the energy content of the fuel input.

The potential of increasing the efficiency of energy use with currently available technology is vast. Two-thirds of U.S. energy use per unit of economic output could be eliminated using available technology, while still maintaining all the functions present-day fuel use performs. With a sensible program of energy research and public policy, it is quite possible to achieve energy use per unit of economic output at one-tenth present levels within a few decades. With some care in energy use, and very high efficiency, economic output can be tripled over the next fifty years while reducing energy use overall by more than three times.

But we still need to supply the energy to do all this - and it will likely be more and more in the form of electricity since it allows a wider range of technological approaches to make energy use more efficient. In the U.S., the growth of electricity required is modest, since the use is already high and there are many opportunities for efficiency. Eventually it may even be possible to begin to reduce this component as well, depending on evolution of technology and lifestyles. In contrast, the growth of electricity required in the developing countries is high because billions of people cannot even meet minimum needs, much less look forward to even modest comforts. And this growth is occurring in much of the developing world, including China and India.

So efficiency alone does not allow us to answer the difficult question of how we are going to get from where we are to a world in which we will have eliminated 50 to 80 percent of CO2 emissions in the next fifty years or so and where those who are poor today have a chance at a more comfortable life.

What are the specific problems of nuclear energy that make it inadvisable as a way to reduce CO2 emissions?

To reduce CO2 emissions from power plants globally significantly, 2,000 to 3,000 nuclear reactors of 1,000 megawatts each would need to be built over the next five decades - thatıs one a week for the next fifty years. This is because about half of present coal and oil capacity would need to be replaced by nuclear (amounting to about 1,000 reactors) and the rest would go towards meeting needs for additional electricity. Even if such a large growth of the industry could be accommodated, it would create many severe risks.

Nuclear power plants and associated technology would be widely used in dozens of countries. The human and technical infrastructure for making weapons and power plants is largely the same. About two uranium enrichment plants of several million kilograms capacity would have to be built each year. The demand for uranium would be so high that separation of plutonium from spent nuclear fuel would be more and more likely and widespread. This is the technology used by North Korea in its weapons program. As another example, Japan could use its commercial plutonium to make nuclear weapons. The leader of the Liberal Party in Japan, Ichiro Ozawa, said in April 2002 that "If (China) gets too inflated, the Japanese people will become hysterical in response," and that "We have plenty of plutonium in our nuclear power plants, so it's possible for us to produce 3,000 to 4,000 nuclear warheads." Japan owns enough plutonium to accomplish this, though some of it is currently stored at the British and French reprocessing sites, where almost all Japanese commercial reprocessing takes place. Japan is also building a large new reprocessing plant at home.

Reprocessing is also part of the nuclear power strategy of the Bush administration. A new reprocessing technology being developed in the United States is more compact and easier to hide. It produces impure plutonium that would not be used by weapons states for bombs, but non-weapons states and terrorist groups would find it attractive. The technology is far more compact and much easier to hide than the present commercial technology. Even with reprocessing, many deep geologic disposal sites for long-lived radioactive waste would be needed - perhaps several each decade.

Even with improved safety, such a large number of reactors would entail the risk of periodic catastrophic accidents. Though the mechanisms and probabilities of accidents are different with different designs, all reactor designs now installed have the risk of accidents on the same scale as Chernobyl. The chance of accidents is very difficult to estimate, but using conventional approaches to risk estimation, such accidents could be expected to occur once every decade or two if a couple of thousand reactors are installed around the world. If inspections and safety are lax, as they may well be if so many reactors are built in a short time, the risks may well be higher.

There is no good approach to disposing of long-lived nuclear waste. The problems of estimating performance of geologic repositories are too daunting and considerable uncertainties will remain regarding impact. Leaving wastes at reactors or other storage sites for indefinite periods is not safe, due to risks of accidents, releases of radioactivity, or terrorism. Geologic disposal is the "least-worst" option but the science must be done free of politics and pressures. This has proved to be difficult. The Yucca Mountain site, the only one being studied in the United States, is, in my opinion, the worst site that has been explored in this country.

To top it all, nuclear energy is expensive and perceived to be so risky that the industry wants government loan guarantees and other concessions even after five decades of insurance and other federal subsidies. A part of the problem is that nuclear energy, far from being "too cheap to meter" as was promised in 1954 by the then-Chairman of the Atomic Energy Commission, Lewis Strauss, is expensive (see below).

One might envision a nuclear power system that is far smaller on the idea that it belongs in an energy mix that would reduce CO2 emissions. But even a system of one thousand reactors would have the same kinds of vulnerabilities. Finally, it is far from clear that development of nuclear power could be sustained if at some point along the line, it resulted in a severe accident in the West or in proliferation that led to terrorists destroying a city. Why take on these vulnerabilities if there is another way to approach the problem?

What energy sources and technologies other than nuclear energy are available for reducing CO2 emissions?

Some facts about electricity generation costs are needed in order to assess how the problem of reducing CO2 emissions can be addressed. At present, U.S. costs for electricity generation in new power plants are approximately as follows (not counting CO2 emissions, or any other external environmental or security costs):