Cap carbon now

Sixth in a series

From the day four years ago when President Bush reversed his campaign pledge to limit carbon dioxide emissions by US industry, the federal government has ignored climate change, the greatest threat mankind has caused to the well-being of the planet. It falls now to the Senate to steer the country toward a more responsible course by including in its energy bill a cap on carbon dioxide emissions.

Electricity generation produces 40 percent of the nation's greenhouse gases, and this page has focused for the past week on ways to provide power without carbon emissions. All of the alternatives considered -- from wind power to conservation to nuclear energy to coal gasification -- deserve more emphasis, but none is cost-efficient enough to make a significant dent in America's production of greenhouse gases unless the carbon emitted by fossil-fuel power plants is taxed or capped.

Bush was right in 2000, wrong since. The United States, which produces 25 percent of the world's greenhouse gases even though it has just 4 percent of its population, has to put its enormous scientific and technological resources to work making carbon-free kilowatts, at the same time the country is tackling CO{-2} emissions from cars and trucks, the other main source of greenhouse gases.

To their credit, some industrial and academic leaders -- even in the absence of leadership from Washington -- are working to curb global warming. General Electric has recently acquired wind and coal-gasification technology and is part of a consortium of companies planning to test new nuclear licensing procedures. Forward-looking energy executives, including Cinergy's James E. Rogers, favor carbon limits so that utilities like his will know what the future holds for them.

The future would be clearer with passage of the carbon cap being pushed by Senators John McCain and Joseph Lieberman. Another proposal before the Senate would also limit CO{-2}, but much less effectively. While McCain and Lieberman aim to cut emissions to the 2000 level by 2010, Senator Jeff Bingaman would let firms slow their rates of emission increases so that by 2020 emissions would be at the 2012 level. His plan would also give industry a cheap way to buy itself out of carbon constraints. A third plan by Senator Chuck Hagel proposes voluntary curbs.

The McCain-Lieberman cap is less rigorous than the Kyoto Protocol, which is endorsed by most major industrialized nations. But it begins to answer the challenge laid down this month by the science academies of the US and 10 other countries. The academies said, ''The threat of climate change is clear and increasing." Alternative energy sources must be part of the answer, and enactment of the McCain-Lieberman cap is a necessary first step toward cutting carbon out of power generation.