We're Carboholics. Make Us Stop.

I am a carboholic. As Americans, we are all carboholics, but I am more so than most. The company I run, NRG Energy, emits more than 64 million tons of carbon dioxide (CO2) into the atmosphere each year -- more than the total man-made greenhouse gas emissions of Norway.

And we are only the 10th-largest American power generation company. Imagine the CO2emissions of Nos. 1 through 9.

Why do we do it? Why does America's power industry emit such a stunning amount of greenhouse gases into the atmosphere in this age of climate change?

We do so because CO2emissions are free. And in a world where CO2has no price, removing CO2before or after the combustion process is vastly more expensive and problematic than just venting it into the atmosphere.

Congress needs to act now to change our ways. Lawmakers should regulate CO2and other greenhouse gas emissions by introducing a federal cap-and-trade system, which would put a cap and a market price on CO2emissions.

If Congress acts now, the power industry will respond. We will do what America does best; we will react to CO2price signals by innovating and commercializing technologies that avoid, prevent and remove CO2from the atmosphere.

I emphasize the word "now." We are not running out of time; we have run out of time. Decisions we make today in the U.S. power industry will have a significant impact on the size of the problem we bequeath to our children.

Without a price on CO2, our industry will build a veritable tidal wave of traditional coal-fired power-generation facilities. Traditional coal plants are, and will be for some time to come, the least expensive and most reliable way to generate electricity on a large scale in the United States, China, India and much of the rest of the world -- that is, so long as the CO2emissions associated with burning coal in these countries remain free.

We absolutely need to use coal for power-generation purposes. We probably even need to build a few more traditional coal plants in fast-growing parts of the country where there is no practical alternative. But we need to move as quickly as possible toward implementing the low-emissions ways of combusting coal that are under development or, in the case of "coal gasification" technology, are ready for commercial deployment.

A federal cap-and-trade system would push the power and coal industries toward deployment of CO2capture and sequestration technology, which is essential to reducing our domestic emissions and, ultimately, to weaning China and the rest of the fast-growing (and emitting) developing world off traditional coal technology. Effective incentives for these new technologies could easily and readily be included in a cap-and-trade regimen. Lawmakers need to provide both the carrot and the stick to get the CO2out of coal.

Energy legislation under consideration in Congress focuses almost exclusively on renewables and conservation; both are worthy initiatives that deserve our support. But in a world where a CO2-emitting traditional coal plant is built every week, renewables and conservation are a sideshow at best.

The vast amount of CO2being emitted worldwide by coal-fired power plants is the heart of the global warming issue. Progress against those emissions depends on three critical initiatives: replacing traditional coal with "clean coal" plants, displacing additional traditional coal plants with new zero-carbon-emissions nuclear plants and implementing a federal cap-and-trade system on greenhouse gases.

Global warming should be at the top of Congress's agenda -- because action by this Congress will turn the tide of climate change around the world. Never before have we faced the prospect of fundamentally damaging our global ecosystem by the day-to-day activities of each and every one of us. A cap-and-trade system is the place to start. America must act now to protect our future.

David Crane, chief executive of Princeton, N.J.-based NRG Energy Inc., a wholesale power generator. NRG, which owns power plants capable of serving 19 million households, recently filed for a license to build two nuclear reactors in South Texas.