(I may take author's license and get on my soapbox at the end.)

Suppose that over the next decade or two the forecasts of global warming start to come true. Color has drained from New England's autumns as the maple trees die. The Baltimore oriole can no longer be found south of Buffalo. The Dust Bowl has returned to the Great Plains. Arctic ice is melting into open water. Upheavals in weather, the environment and life are accelerating around the world.

Then what?

If global warming occurs as predicted, there will be no easy way to turn the Earth's thermostat back down. The best most scientists would hope for would be to slow and the halt the warming. This would require a top-to-bottom revamping of the world's energy systems, shifting from fossil fuels such as coal, oil and natural gas to alternatives that, in large part, do not exist.

But interviews with scientists, environmental advocates and industry representatives reveal no consensus on how to meet the challenge. Some point to renewable sources like solar, wind, geothermal, biomass, hydroelectric and such. Others believe that the use of fossil fuels will continue, but that Carbon Dioxide can be captured and used. Nuclear power advocates hope that concern over global warming might spur a commercial revival.

Dr. Martin I. Hoffert, a physics professor at NYU and 17 other scientists cited in the journal Science last November looked at alternatives to fossil fuels and found all to have "severe deficiencies in their ability to stabilize global climate." A technological fix is possible, but the effort must begin now. A program on the scale of the Manhattan Project or the Apollo program will be necessary. "We should be prepared to invest several hundred billion dollars in the next 10 - 15 years," Hoffert said.

The heart of the problem is carbon dioxide (CO2). An atmosphere rich in CO2 traps heat, producing a greenhouse effect. Most scientists believe that the billions of tons of CO2 released since the start of the Industrial Revolution are in part responsible for the 1-degree rise in global temperature during the last century. CO2 concentrations are now 30% higher than preindustrial levels. Rising standards of living in developing countries are causing even more carbon dioxide to be released, speeding up the pace of warming.

The United States produces more CO2 than any other country, by far. The average American produces about 45,000 pounds a year. That is about twice the amount produced by someone living in Japan or Europe. Even if President Bush's goal of an 18% reduction in CO2 emissions by 2012 was met, the average American would still produce more than anyone else in the world.

Approximately 85% of the world's power is produced by fossil fuels. The rest comes from nuclear, hydroelectric, wind and solar. Energy Secretary Spencer Abraham cited the Science paper in a speech to the American Academy in Berlin. He said that merely setting limits and timetables on CO2 like those in the Kyoto Protocol could not by themselves solve global warming. "We will also need to develop the revolutionary technologies that make these reductions happen. That means creating the kinds of technologies that do not simply refine current energy systems, but actually transform the way we produce and consume energy."

Fusion reactors are still some time off. Scientists have not shown it can be harnessed practically. Increased energy efficiency is not a solution in itself, but could buy time. Hydroelectric power has reached its limits. There are no more rivers to dam. Nuclear power is a proven technology that must overcome public fears about accidents, like Chernobyl and 3 Mile Island. Solar power must undergo more development before it becomes cost-effective. Wind power is already practical in many places and competitive with natural gas, but may have to overcome NIMBY concerns in the US. Both solar and wind are intermittent sources of power. To fully exploit them would require batteries to take their place when the wind isn't blowing or the sun isn't shining. Hydrogen produced by fossil fuels would be no help.

One big idea is to move the solar arrays into orbit, where the sun shines 24/7, and beam the energy back to earth via laser or microwave. Another might be to develop a way to scrub CO2 out of the atmosphere, capturing it for other uses.

Here is where I get on the soapbox. Hope I don't fall off.

The failure of fusion to prove itself is not a failure of theory but of will. Fusion research has been chronically under funded for years. In spite of that, scientists are very close to a proof-of-principle device in inertial confinement and laser fusion.

If the nuclear industry is allowed to reprocess spent fuel the waste disposal problem goes away. If the average American's electricity needs were met by nuclear power only and the spent fuel was fully reprocessed, the amount of waste would be about the size of three stacked quarters. A reprocessing plant was built years ago and it had to be mothballed due to public sentiment. Once fusion reactors are available, the amount of waste would be reduced even further.

Fusion and fission reactors in combination have the capability of transforming the world. Power generation with almost 100% efficiency and no emissions. Desalination in remote areas. Fresh water for irrigation. Mineral reclamation. Hydrogen for cars.

Solar in space is feasible, but the cost will be high. In order to support the enterprise, launches will be required every day, if not several times a day. That means new launch facilities, transportation, launch vehicles, fuel plants, power plants and every thing else required to launch at a cost of pennies per pound in orbit. Lasers or microwaves could be used to beam the power back to Earth. You would still have to overcome the public's perception that crossing the power beam, even accidentally, would be dangerous.

Do we have a global warming problem? I'm not totally convinced. Is CO2 a problem that needs to be addressed? Yes. Would I like to see fossil fuels used for other things? Of course. Used as petro-chemicals, fossil fuels would go farther and last longer.

We can't afford to let this become a crisis. With the recent blackout in the Northeast, we can see that not only power generation but transmission are on the edge. Let's be good stewards.

Source: Kenneth Chang, New York Times, Nov. 9, 2003, pg D1 and D5