Why wait for international treaties? Stabilizing the Earth's climate is a problem ordinary people can help solve. Cut your own greenhouse gas emissions and save money, improve health, and reduce dependence on Middle East oil.

For example, the U.S. Department of Energy estimates that each American adds 6.6 tons of greenhouse gases to the atmosphere annually from gas, electricity, and the processing of products. Widespread adoption of renewable energy sources such as solar, wind, geothermal, biomass, and fuel cells could cut that pollution by 32 percent, the agency estimates.

Conservation helps, too. Energy think tanks such as the Rocky Mountain Institute of Snowmass, Colorado, estimate that individuals can slice energy consumption in half with insulation, modern appliances, energy-saving light bulbs, and modest adjustments to the thermostat.

Can an individual really make a difference? You already do by living the lifestyle you were born to. The consumption of the average American produces 25 times the greenhouse gas emissions of a typical person in India.

Yet reducing atmospheric pollution doesn't mean adopting the lifestyle of an Indian peasant. It means steady investment in new technology that will pay off in the long run.

Some contributions are simple. Planting a tree in your yard produces wood that soaks up carbon dioxide, provides shade to lessen the need for air conditioning, and shelters homes from winter winds.

Recycling of waste lessens the need for logging, mining, and the energy to process raw materials.

If Americans could work from their homes an average of one day a week, U.S. oil consumption would be reduced up to 10 percent, far more than would be gained by drilling in the Arctic National Wildlife Refuge.

Insulation, weather-stripping, energy-efficient windows, newer appliances, fluorescent light bulbs, water-saving showerheads, and lower settings on thermostats and water heaters all save money and cut greenhouse emissions.

Buying lumber certified as having been grown and harvested responsibly helps promote good forestry. The purchase of tropical forest food products while not buying tropical hardwoods also encourages forest preservation.

Simply buying a fuel-efficient car can prevent emission of hundreds of pounds of greenhouse gases every year.

Even more exciting is the maturing of alternative energy industries that could make fossil fuel consumption a relic of history. A single large coal-fired or nuclear generating plant makes about 1,000 megawatts of energy, enough to power a big city. In the U.S., dams already provide 77,000 megawatts, geothermal 2,800 megawatts, wind 2,500 megawatts, and burning or composting of plant material, called biomass, 7,000 megawatts. Photovoltaic cells that turn sunlight directly into electricity are commonplace on remote locations and feed the electrical grid in 36 states. Some homeowners who have added wind generators or solar panels to their homes have reverse meters that give them credit for surplus energy they feed to the power grid. All save on power bills.

No power source is problem-free, of course, but more exotic technologies are on the horizon. Solar cells are being integrated into shingles that look like asphalt and slate. Under development is window glass that generates electricity. Homeowners willing to pioneer the adoption of such products can help spur further development of the technology.

Some changes are so expensive and complex that they must be financed by large industry. The use of hydrogen as a fuel is an example. Hydrogen is the most abundant element in the universe, contains more energy than gasoline, and when "burned" in fuel cells it emits only water as a by-product. To replace gasoline, however, hydrogen must be manufactured, transported, and stored on a scale equal to the gigantic oil industry.

This is just beginning to happen. Test buses, cars, and portable power plants that use hydrogen fuel cells are already operating. Usable hydrogen is not yet plentiful, but can be extracted from water, natural gas, or the methanol that comes from organic garbage and compost. Major automakers are experimenting with prototype engines. Still being debated is the best way to make, deliver, and safely store hydrogen, and ordinary consumers must wait until fuel cells are more widely available. Someday, each home may have its own hydrogen fuel cell power plant.

Meanwhile, Toyota and Honda have introduced hybrid gasoline-electric vehicles with considerable success, with the cars posting up to more than 40 miles per gallon. The U.S. Department of Energy is working with automakers to achieve a full-size sedan that achieves 80 mpg by 2004.

By buying such cars or writing automakers in support of new technologies, individuals can encourage the transition to vehicles that minimize greenhouse gas emissions.

Every success supports more dramatic efforts. For instance, researchers are encouraged to consider capturing the energy of the oceans. The world's surf generates as much power as 2,000 to 3,000 big power plants. Dams could tap tidal energy, or generators could be placed in tidal currents. There is even experimental technology to take some of the solar heat absorbed by the oceans each day - equivalent to 250 billion barrels of oil - and convert it to electricity, with fresh water as a byproduct.

Superconducting materials, if they become practical, could save enormous amounts of energy by making motors and power lines much more efficient.

So why aren't these bright ideas already adopted? Because the fossil fuel industry, which has been developing since the dawn of the Industrial Revolution, can deliver energy cheaply in the short run. If we overheat the planet, however, cheap gas may seem like a devil's bargain.