WASHINGTON -- With the cap-and-trade bill passing the House of Representatives last week by seven votes, the eight Republicans who supported it were bound to feel some rapid, political warming. Conservative Internet and radio accused them of single-handedly passing President Obama's "cap-and-tax" legislation, which is a myth; Speaker Nancy Pelosi likely would have forced the requisite number of Democratic votes in the absence of Republican backing. But these eight Republicans were still termed "traitorous."

It is typical that we praise independent judgment and political nerve in our elected officials -- until they actually show those qualities.

Admittedly, this was not the best time to display conspicuous Republican environmental conscience. Obama's ideological overreach on issues from the fiscal stimulus to health care nationalization has put conservatives in a scrappy mood. The recession has brought the public's economic anxiety into sharp focus, while moving environmental concerns -- droughts in the Sahel or floods in Bangladesh -- into the hazy distance. And the House cap-and-trade bill itself was a riot of loopholes, concessions and offsets -- legislative sausage-making with an excess of offal.

But none of these political considerations change an underlying reality. A serious concern about global climate disruption remains the broad (not unanimous but predominant) view of the scientific community, including the National Academy of Sciences. Global warming since the 19th century is undeniable -- a trend not disproved by year-to-year variations. These changes are closely correlated with increases in the atmospheric concentration of carbon dioxide since the Industrial Revolution. Climate disruption has become so rapid in some places that it is overwhelming the natural process of adjustment, reducing crop yields and leading to the extinction of species. Meanwhile, global carbon emissions are increasing faster than expected. Some scientists warn of possible "tipping points" -- the rapid disintegration of the ice sheets, the sudden release of methane from warming northern soils -- that could turn a challenge into a catastrophe of lethal heat waves and rising sea levels.

Is this scientific viewpoint certain or guaranteed? Not when the scientific models concern a system as complex as the Earth's climate. Neither is it guaranteed that an Iranian nuclear weapon would be used against that country's enemies. But the realistic possibility of disaster, in both cases, would recommend a serious response.

The range of serious responses is limited. The federal government might spend directly on new technologies that produce energy without emitting carbon. But government's record in picking technological winners and losers is poor.

Others propose a carbon tax -- a cost per ton emitted, with no special exemptions. This system would be simple to implement and difficult to game. But it would also disproportionately punish some energy-intensive American industries -- cement, glass, steel and paper -- that face intense international competition.

The final alternative is a cap-and-trade system, which sets an overall limit on carbon emissions while directing relief to specific industries through rebates and offsets. Cap-and-trade has been used with dramatic success to reduce acid rain -- but it has never been employed on the massive scale that the regulation of carbon requires.

Critics argue that carbon restrictions, even if fully implemented, would only reduce global temperatures by minor amounts, which is true. We are not going to regulate our way out of global climate disruption. The only eventual solution is technological -- the ability to produce affordable, clean power on a large scale.

But conservatives seem strangely intent on ignoring the power of markets to encourage such innovation. Right now, the emission of carbon is essentially cost-free. Putting a price on carbon would make the development of cleaner energy technologies more profitable. New technologies could be employed, not only by America, but also by China, India and the rest of the developing, polluting world. And it is an added (but not minor) benefit that American resources would no longer be transferred to Saudi princes, Russian autocrats and Venezuelan dictators.

It is perfectly legitimate to argue that the House cap-and-trade system is flawed beyond redemption -- so complex and confusing that it only benefits regulators and the lobbyists who outwit them -- and that Congress should start over with a carbon tax.

It is also legitimate to contend that, while the cap-and-trade system is flawed, it is better than inaction and necessary to spur innovation. And for eight House Republicans who took this stand at great political risk, it is not only legitimate; it is admirable.