The House Energy and Commerce Committee last week took a major step toward reducing greenhouse gas emissions. It approved a bill that would cap releases of heat-trapping gases and create a national market to trade pollution credits.

The bill comes on the eve of talks that will set the stage for a new international treaty to reduce carbon dioxide emissions. The old treaty — the much-discussed Kyoto Protocol that the United States refused to sign — is set to expire in 2012.

Any new agreement will have to ask more of developing countries - including China and India — that were exempted from previous limits. But the United States can't credibly ask them to reduce their emissions if it refuses to curb its own.

The climate change bill approved last week faces many serious challenges before it can be considered by the full House of Representatives. It already has been watered down to satisfy some powerful interests. But that hasn't stopped critics from mounting a major disinformation campaign to defeat it.

At the heart of this disinformation campaign is a false choice — vote for the so-called cap-and-trade bill and face higher energy prices, or do nothing and keep costs low. It's a seductive but specious argument.

In reality, the status quo comes at an unsustainable cost. Global warming already is occurring. Even if all greenhouse gas emissions stopped tomorrow, the effects would be felt for decades.

Climate change imposes very real costs on all of us, on our children and on our grandchildren. We are subsidizing current energy prices at the expense of our progeny. The longer we defer payment, the higher those costs will be.

In a landmark 2006 report, the British Government Economic Service warned that delay could reduce the world's gross domestic product by between 5 percent and 20 percent. That would occur because of a simultaneous need to switch from carbon-based energy to some other source and to address negative effects of climate change that were decades in the making.

It is as if we are financing our lifestyle with an interest-only mortgage. There's a big balloon payment looming in our future, but we've refused to set anything aside to pay it.

As originally proposed, the cap-and-trade system would have required companies to bid for permits that would allow them to emit greenhouse gases.

The idea was to encourage them to reduce emissions and reward those that succeeded. Companies that failed to cut back would pay a penalty; they'd buy permits from the companies that no longer needed them.

But that's not how the bill approved last week works. Most permits would be given away, many to utilities like Ameren that generate electricity by burning coal.

Giving away permits reduces the financial impact on consumers. But it also substitutes political considerations for market forces to determine who gets to pollute. Favored industries like electric companies get lots of credits. Less favored industries like oil companies get very few.

Despite those drawbacks, the cap-and-trade bill represents an important advance because it has a realistic chance of being approved.

If we do not start reducing our global warming liabilities now, we will be overwhelmed with the debt later. We can't do that by wallowing in denial.

REPRINTED FROM THE ST. LOUIS POST-DISPATCH.