Smog over Los AngelesPresident Obama is betting that a cap-and-trade program can help solve the climate crisis. Southern California leaders hoped the same thing when they set up a cap-and-trade program to clean up the region’s air. The results? See above. Photo: jordansmall via Flickr

Nearly 20 years ago, a novel program called “cap and trade” was rolled out by Congress and the U.S. Environmental Protection Agency. The aim was to keep rural Northeastern lakes from being tainted by corrosive “acid rain” created by power plant emissions hundreds of miles to the west.

Under the cap and trade, everybody would win. A whopping half of all the sulfur dioxide-the key ingredient in acid rain-would be cut more quickly and cheaply than if the companies were forced to do it under straight regulation. Lakes, forests and streams, and the fish and people living in and around them, would be spared further ravages.

The program succeeded spectacularly, with emissions targets reached three years ahead of schedule, at an estimated 75 percent in industry savings.

But did it halt acid rain?

Not exactly. In fact, researchers say many lake and stream beds are still highly acidic, and the problem is now spreading to the Southeast. They estimate another 50 percent to 70 percent cut in the remaining sulfur emitted by power plants is needed to really lick the problem.

If the House American Clean Energy and Security Act survives the Senate, what exactly has Congress bought into on behalf of the American public? There is a long, little discussed track record for other cap-and-trade programs. Leaving aside the money, the results are sobering. Not one has definitively cleaned up a major environmental problem. Adding insult to injury, environmental justice advocates say the market programs have allowed power plants and other industry routinely sited in poor, minority neighborhoods to keep spewing out toxic pollution by buying credits from elsewhere.

It’s true that some cap-and-trade programs are still new and others have demonstrably helped reduce pollution. But there is simply no precedent showing that a cap-and-trade system would deliver in time the significant cuts in greenhouse-gas emissions that scientists say are critical to prevent catastrophic climate change. To the contrary, past programs have been dogged by start-up challenges and, even more disquieting, surprises from Mother Nature.

It helps to think of existing programs as a family while delving through the acronyms and mind-twisting verbiage of cap-and-trade policy. There’s the founding father patriarch in D.C., the “out there” California uncle people tend to forget about, the globe-trotting European cousin, and Reggi, the new kid on the block in the Northeast, jumping up and down yelling “look at me, Ma!”

Below is an overview of the cap-and-trade family tree based on interviews with staff and online documents. We’ll leave the shouting to others for now.

What is cap and trade?

The “cap” is a legal limit set on one type of air pollution. A coal fired power plant is told it cannot emit more than a certain number of tons of carbon dioxide per year, and is allocated one credit for each ton it is allowed to emit. Each year the cap is lowered, until the pollution is reduced to a level that scientists and regulators deem safe.

The “trade” refers to the market trading of those pollution credits. Polluters who clean up their act so much that they are well below their yearly cap can sell the leftovers for a tidy profit to others that cannot or will not meet their own cap. In some cases the government auctions the allowances instead of allocating them.