IF the world is going to meet its energy demands without threatening the environment, it will have to use more nuclear power. That is the message Hans Blix, director general of the United Nations International Atomic Energy Agency (IAEA) brought to the United States and the UN last week.
Concern about the greenhouse effect - the gradual warming of Earth's atmosphere that scientists suspect is under way - means we must burn less fossil fuel, Dr. Blix says. He believes the only real alternative to oil, gas, and coal is nuclear power.
Blix, a former Swedish foreign minister, points out that carbon dioxide (CO2) gas is thought to cause about half of the greenhouse effect. The buildup of CO2 in the atmosphere is caused mainly by the use of fossil fuels.
While environmentalists say CO2 can be reduced through conservation or by using more renewable energy, Blix says, these solutions will not meet the world's increasing energy demands.
The director general concedes that some gains can be made through conservation. But these will be offset by the increasing number of automobiles and electrical appliances in the world, he says.
Renewable energy sources - water, wind, and solar power - are not the answer either, Blix says. They now supply only 0.3 percent of world energy needs. The International Energy Agency in Paris estimates that renewable energies, other than hydroelectric power, will contribute only about 5 percent of Western needs by 2010. The World Energy Conference estimate was 3 percent.
The alternative is nuclear power, he says. ``The public should be aware that nuclear energy emits no nitrous oxides or sulfur dioxides, the two sources of acid rain and dying forests. And there is no carbon dioxide whatever. Nor does it give rise to any toxic heavy metals, which coal, for instance, does,'' Blix asserts.
Opponents of nuclear power point to the safety issue, the waste-disposal issue, and the risk of nuclear-weapons proliferation. The director general has rebuttals for these concerns, too:
Proliferation. There has not been a single case in which the transfer of nuclear technology for peaceful uses has led to weapons development, Blix states. He points out that 200 IAEA inspectors inspect about 95 of all civilian nuclear installations worldwide to guard against such diversion of nuclear materials.
Safety. Nuclear energy must be fairly compared with other types, Blix says. He says the public should ask, ``What is the risk per kilowatt received?'' for each energy source. While at least 31 people died in the Chernobyl accident, the safety record of fossil fuels is nowhere near as good as that of nuclear power, he says. For example, he notes:
This year, more than 600 people died when a leaking natural gas pipeline in the Soviet Union exploded as two passenger trains passed it.
More than 150 workers died when a North Sea oil platform capsized in 1988.
Thousands of coal miners have died over the years around the world.
In India, some 15,000 people lost their lives when a hydroelectric dam burst in 1979.
Waste. ``The nuclear community has not conveyed to the public that there are no technological obstacles to the safe disposal of nuclear waste,'' Blix says. The problem is political, not technical. He quotes Herbert Kouts of the IAEA International Safety Advisory Group: ``The `unsolved' problem of radioactive waste is more political than technical and will require more guts than brains to solve.'' Blix maintains that the scientific community is confident long-term storage of nuclear waste; the problem is that no one will accept a site.
Blix disagrees with the World Commission on Environment and Development, headed by former Norwegian Prime Minister Gro Harlem Brundtland, which claims that world energy use can be trimmed 50 percent by 2020. Blix points instead to the World Energy Conference, which predicted in Montreal that global energy use will increase 75 percent by that year.