If great nations are defined by their ability to respond effectively to great challenges, America is in trouble. Witness what happened on Capitol Hill to comprehensive climate change legislation. The political process succumbed to greed, cowardice and the sclerotic effects of partisanship.

Climate change is real, according to the worldwide scientific consensus, a point underscored repeatedly by the National Academy of Sciences. The deniers of reality who had claimed that leaked e-mails from climate scientists proved the theory bogus have since been confounded by reputable investigations.

Mother Nature itself has seemed to make the point this year with a record-breaking stretch of hot weather (although too much can be made of this because the long-term trends are what count). To top it off, the Gulf oil spill has reminded Americans of the devil's bargain struck by dependence on fossil fuels that beget greenhouse gases.

An observer from another planet might think the time had never been more ripe to meet this challenge. And, tantalizingly, it seemed this summer that comprehensive climate change legislation stood a chance if its proponents fought hard. But no. Senate Majority Leader Harry Reid has folded.

The special interests that have Congress in their thrall have done their work. Cap and trade, a market mechanism to regulate and limit greenhouse gases that started life as a Republican idea, was so demonized by the GOP as a tax that in the end the Party of No didn't have to bother to vote "no."

In its place, Mr. Reid offers the Clean Energy Jobs and Oil Company Accountability Act, which bids goodbye to cap and trade. In its place is a face-saving grab bag, which seeks to impose conditions on oil companies dealing with oil spills by increasing the liability cap from $1 billion to $5 billion and requiring them to pay 49 cents a barrel into an oil spill liability trust fund. Among other provisions, $5 billion would be provided for the Home Star program, which will offer sales rebates to homeowners to make energy efficiency upgrades.

These steps, which Congress will act upon as early as today, may do a little good -- but, sadly, a little good will not be good enough to meet the planet's critical environmental challenges.

Cartoonist Rob Rogers does "Rob's Rough," an early look at his work and his creative process, exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.