As the leading national consumer of fossil fuels, the United States churns out almost a quarter of all the industrial carbon dioxide worldwide. Apologists say this is the price that must be paid in exchange for driving the global economy. Realists see such hubris as eventually undermining human viability on Earth through pollution and climate change.

U.S. inaction on its oil dependency is doubly frustrating because there are now "renewable" energy sources that offer practical alternatives to coal and oil. If the U.S. were to begin the switch to renewables now, there is every reason to expect a global win-win situation within decades, economically and environmentally.

America's passive acceptance of fossil-fuel dependence is also particularly disheartening because it is the only nation with the wealth, technological expertise and international leverage needed to lead a global energy revolution. If the U.S. does not bring its own energy juggernaut under control, then unprecedented international cooperation will be required for the world community to set a new and saner course.

U.S. President George W. Bush has already proved himself wedded to U.S. and Saudi oil interests, meaning his administration will never seriously promote alternative energies.

The probable Democratic Party presidential candidate, Sen. John Kerry, is a disappointment, too, for not championing this issue. His call for a "Manhattan Project" on energy appears limited to supporting more efficient cars and ethanol fuel, which -- being made from corn -- is cleaner than gasoline, but is more likely aimed at appeasing farmers than ending U.S. oil dependence.

It is no wonder this year's election has environmentalists woefully uninspired. Still, there is reason for optimism, as well as a potential field day on the horizon for investors and socially responsible lobbyists.

One group keeping a close eye on renewables is the Worldwatch Institute, an independent, Washington-based research organization which recently published a booklet titled "Mainstreaming Renewable Energy in the 21st Century." Authored by Janet L. Sawin, this takes a short, but encouraging, look at replacing fossil fuels with clean renewable energies.

So first the bad news on alternative sources of energy. "New renewables," as Sawin calls them, currently supply just 2 percent of total global energy demand. In fact, "a mere six countries -- Denmark, Germany, India, Japan, Spain and the U.S. -- account for about 80 percent of global photovoltaic and windpower capacity," she writes.

New renewables include all renewable energy sources except those from large-scale hydropower (dams) and traditional biomass, such as wood that is burned for heating and cooking. The best known of these new power sources are wind, solar, geothermal (underground steam and hot water) and tidal energy. However, even as global energy demand climbs, renewables are lamentably underexploited. Fully 2 billion people in the developing world still lack electricity and, as Sawin notes, the International Energy Agency predicts that by 2030, "global energy consumption will increase 66 percent and electricity use could double."

Either because they are ignorant or in denial, most nations still blithely expect oil to provide this energy. Mother Nature, though, has a shock in store. Now, at a time when we are wholly dependent on oil for most of our energy needs, world oil production is about to peak. In fact, some observers say it already has. This means even higher prices and increasing conflicts over a grimy fuel that degrades our environment at every step, from its extraction to its transportation, refining and burning.

The irony is that most of us don't care where our energy comes from, we just want unlimited energy now -- and we want it cheap.

All of this plays right into the hands of multinational oil companies. Their advertising campaigns assure us they are committed to pursuing new energy sources, but out of their billions in annual profits, mere millions go to bringing alternative energies online.

"Change is never easy, and there are strong forces (including politically powerful industries) acting to maintain the status quo," Sawin notes early in the book. She concludes it on the same point: "Today most of the world is locked into a carbon-based energy system that is neither better nor necessarily cheaper than renewable energy, but merely the legacy of past policies and investment decisions."

But there is good news that offers hope for change. Forward-looking policymakers worldwide are beginning to recognize that renewables offer a clean and sustainable energy future.

"Political support for renewable energy is on the rise as strong new legislation opens markets for renewable energy in a rapidly growing list of countries. Many nations view renewable energy as not only a credible alternative to fossil fuels, but also a necessity to meet growing energy needs without sacrificing quality of life, human health, the natural environment and national security," explains Sawin.

Investment is up, too. In 2003, global investment in renewable energy topped $20.3 billion, "about one-sixth of total global investment in power-generation equipment," according to Sawin. In fact, the fastest growing energy sources in the world are wind and solar power, and global wind-energy generation capacity has grown at an average of almost 30 percent annually over the past 10 years.

Got shares in an oil company? Dump them quick. Renewables are the next Microsoft.

"Though a transition to renewable energy will require considerable upfront investment, numerous studies conclude that it would be cheaper over the long term [than fossil fuels], while also providing tremendous social, economic, security and environmental advantages," asserts Sawin.

In the U.S., California is leading the switch, and Japan and Germany have already made good progress in solar- and wind-energy generation respectively, proving that not all governments have their heads stuck in desert sand.

And government action is key. "In all cases, the advancement of renewables has been spurred by strong government policies designed to nurture nascent energy industries and to create demand for these technologies, often in markets dominated by mature, heavily subsidized fossil fuel and nuclear power," says Sawin.

But unless we demand clean energy, oil lobbyists will continue smoozing politicians into spending your taxes on subsidizing their industry, with tax breaks for oil and coal and legislation that slows a switch from antiquated fossil fuel infrastructure to clean renewables.