Last year, comprehensive climate and energy legislation was well on its way to becoming law. After a version passed the House, pundits were concerned mostly with whether it would be passed in time for the Copenhagen climate talks last December. But Senators balked, and a drive this summer to put some sort of bill together has stalled.

Yesterday, Senate Majority Leader Harry Reid (D-Nev) threw up his hands, giving up on a comprehensive bill for now in favor of a narrow energy bill without any limit on greenhouse gas emissions or regulations to require renewable energy. What's left are measures to hold BP accountable for the oil spill, to invest in natural gas trucks (the pet project of oil and natural gas tycoon T. Boone Pickens), to improve home energy efficiency, and to restore money to the Land and Water Conservation fund.

Reid says he'll still work on a comprehensive bill, but it looks like it's out of play for the year.

Last week researchers and policy experts gathered at MIT to talk about geo-engineering--a subject that's becoming more popular in the face of concern over inaction on climate change.

The upcoming United Nations climate change convention in Copenhagen seems unlikely to produce the binding and stringent agreement needed to sharply curtail greenhouse gas emissions. Meanwhile, greenhouse concentrations continue to mount, driving scientists who were once opposed to the idea of tinkering with the planet to reconsider it.

Now they've got another reason to be worried. Earlier this year a climate bill that would've limited greenhouse emissions and helped renewable energy sources compete with fossil fuels seemed well on its way. In June a version passed the House. But then other matters--mostly health care reform--distracted Congress, and a Senate version of the bill got bogged down. The Senate recently took up the bill again, but yesterday a report in the Washington Post declared that "there is almost no hope for passage" of the bill.

Democrats are divided over the bill, and Republicans have been vocally opposing it. If the report is right, countries meeting in Copenhagen will have even more reason to criticize the U.S. for inaction, and to use that as a reason to delay a climate treaty or water it down.

That's one way to look at it, at any rate. Here's another: Copenhagen is probably doomed already--why the rush to push legislation through? That's essentially what Republican Senator George Voinovich (Ohio), who opposes the current bill, reportedly said last week, "Wouldn't it be smarter to take our time and do it right?"

It certainly is hard to be against getting something right. But will slowing things down lead to a better climate bill? Probably not, as long as the chief objection is that the bill will make energy more expensive, something that seems unavoidable. But if the delay can lead to a better system for distributing those costs equitably, and if along the way inefficient subsidies can be weeded out and emissions caps tightened (wishful thinking?), it could be worth the wait.

One of the potential problems with the energy and climate bill now working its way through Congress is its size. It's bound to be full of hidden loopholes that could help various interest groups, probably making doing something to slow climate change more expensive.

Economists have already pointed out at least one subtle problem that could lead to higher costs. Certain industries, such as the steel industry, will be awarded allocations for emitting greenhouse gases according to how much they produce in the first place, and these allocations will be updated periodically, as their output changes. This gives them the perverse incentive (as economists like to put it) to generate more emissions so that they can reap more of the potentially valuable allocations, which they can sell on a carbon market. The overall carbon emissions for the United States won't increase--the overall cap doesn't change. But giving more allowances to steel manufacturers means that other industries won't get as many. That could drive up the cost of electricity, for example.

The solution, says Gilbert Metcalf, a professor of economics at Tufts University, is to change from output-based updating of allocations to setting allocations based on emissions before the law goes into place.

Today, the Washington Post uncovers another subtle detail of the bill that it says could be worth millions of dollars to oil refiners.

During the final days of the drafting of a 946-page climate bill, Rep. Gene Green (D-Tex.) won support for an amendment that deleted a single word and inserted two others. The words could be worth millions of dollars to U.S. oil refiners.

The Green amendment deleted the word "sources" and inserted "emission points." In the arcane world of climate legislation, that tiny bit of editing might one day give petroleum refiners valuable rights to emit carbon dioxide when it otherwise might not have been allowed. Refiners could get the extra allowances in return for cutting carbon emissions by 50 percent at a single point of a vast refinery complex instead of slashing emissions by 50 percent for the entire facility.

The article goes on to mention a couple more loopholes, and surely in this long and convoluted bill there are more that aren't obvious. Some more may simply be the result of unclear wording. Again, they won't change the total emissions as long as the overall cap stays in place, so the bill still has some teeth. Indeed, Robert Stavins, director of the Environmental Economics Program at Harvard University, says that the political wheeling and dealing could be a good thing: it could get more people behind the bill, which could make it more likely to pass.

That said, some of the worst polluting industries--as long as they have strong lobbyists--might get away with doing little to change their ways, passing on the burden to others.