Since Hillary Clinton announced her support last week for suspending the federal gas tax between Memorial Day and Labor Day, the press has marshaled economists and environmentalists from around the country to wholeheartedly denounce the idea. Of course, it’s not really the soundness of the plan that the media are after, or else they would have mounted a similar charge when Republican John McCain called for the gas-tax “holiday” in mid-April. Journalists jumped into action this time because Clinton’s proposal created a situation in the Democratic party that is no longer possible on the GOP ticket: division.


Division between Clinton and Barack Obama, who has called her gas-tax proposal a political “gimmick,” is a good thing, though, especially when it comes to energy issues, upon which they have mostly agreed until now. As evidenced by the lack of critical attention to McCain’s call to suspend the 18.4-cent federal tax, however, the press often doesn’t get around to teasing out division until it is blatantly obvious (and in this case, perhaps, short-lived, after Clinton’s anemic performance in Tuesday’s primaries).


That’s too bad, because the recent debate about the gas tax hints at a parallel and equally important, but largely unexplored facet of the cap-and-trade legislation that both Clinton and Obama (and McCain for that matter) support: the so called “safety-valve” clause.


One of the reasons that the safety-valve clause hasn’t received much attention from the media is that it’s nominally a feature of the Low Carbon Economy Act, a cap-and-trade bill sponsored by Senators Jeff Bingaman, a New Mexico Democrat, and Arlen Specter, a Pennsylvania Republican. The safety valve guarantees American companies that the price of one carbon credit (which is a permit to emit one metric ton of carbon dioxide or its equivalent in other greenhouse gases) will not rise above $12 in the first year, and increase 5 percent annually beyond inflation after that.


The Bingaman-Specter legislation has not received anywhere near the amount of coverage that the stricter, but more popular Climate Security Act has gotten. The Act, which was introduced by senators Joe Lieberman, a Connecticut independent, and John Warner, a Virginia Republican, doesn’t have a safety-valve clause, but it has something similar - a Carbon Market Efficiency Board that will release credits to bring down the cost of polluting if the price of emissions gets too high and threatens the economy.


The safety valves in the two pieces of legislation are different from the gas-tax holiday in many respects, but essentially they’re all designed to pull the plug on high carbon prices if Americans (especially those in the lower economic strata) begin to struggle financially. And ultimately, both the safety valves and the gas-tax holiday favor consumers and benefit the fossil-fuel industry by hobbling, to some degree, programs that were designed to facilitate the shift to renewable sources of energy. Thanks to the last week of electoral bickering, we know how each of the candidates feels about suspending the gas tax, but what about the safety valves in the two cap-and-trade bills?


Clinton, Obama, and McCain all support some form of cap-and-trade legislation. Clinton voted for the Lieberman-Warner bill in an Environment and Public Words committee markup, but Obama’s and McCain’s inclinations are still unclear. Regardless of political backing for either bill, though, the press has failed miserably at comparing them in any useful or analytical way. There have been reams of stories, of course, that dissected the cap-and-trade system more generally and compared it to a carbon tax, which is an alternative emissions reduction strategy. Few journalists have picked apart any of the fine differences between various forms of cap-and-trade, however.


Last week, Ceres, a coalition of investors that pushes companies to reduce emissions, and the National Resources Defense Council, released a little-noticed report that specifically compared the financial impacts, on power companies and consumers, of the Climate Security and Low Carbon Economy Acts. According to Ceres’ chief press officer, Peyton Fleming, the group based its calculations on a carbon emission price of $10 per ton, an admittedly low value, in part because of the safety valve clauses in the two bills. “We recognize that the cost of emissions is likely to be higher,” he said in an interview, “but we didn’t want to use that immediately and have [the bills’ sponsors] turn around and complain that safety valve will keep prices down.”


Keith Johnson at The Wall Street Journal’s Environmental Capital blog picked up the Ceres/NRDC report, making him one of the few journalists to base an article (or blog post as it were) on a comparison of the two climate bills. Still, because the report did not explicitly mention the safety valve or how it factored into the equations, the Journal entry didn’t either. “The gas tax is something that will affect people within the next four months,” Fleming said when asked about the dearth of coverage, “The safety valve is a complicated issue that won’t come into play until at least 2012.”


An article in E&E Publishing’s recently launched ClimateWire news service seems to be one of only two media accounts to dedicate their entire length to the subject (the other came from the Marketplace radio show last October). It is a long and fascinating account of the thirty-year history of the safety valve concept. It didn’t start with climate, but has evolved over the last decade to fit the mold. In 1997, the Clinton administration considered adding a safety-valve clause to the U.S. position at the U.N. climate negotiations that led to the Kyoto Protocol. It was dropped, however, after the idea met strong criticism from environmentalists. Bush thought about including a safety valve after his campaign pledge to regulate carbon dioxide, but he eventually abandoned regulation entirely.


McCain rejected a proposal to include a safety valve in the 2003 Climate Stewardship Act he sponsored with Lieberman. A year later, however, the National Commission on Energy Policy, a bipartisan coalition of industry, environmental, and political representatives, recommended that one be added to any cap-and-trade scheme in order to make it politically feasible (i.e. acceptable to industry and consumers). Apparently heeding that advice, Bingaman did exactly that when he pitched his draft legislation to Republican senators, including Specter, in 2005. Since then, debate has raged, pitting environmentalists, who think safety valves cripple climate legislation, against industry, which thinks having the failsafe is the only way to make cap-and-trade work.


It’s unclear what Obama and Clinton think. Yesterday, Grist’s David Roberts had an interesting Q&A with Jason Grumet, a climate and energy adviser to the Obama campaign who is also executive director of the National Commission on Energy Policy, which authored the 2004 report promoting the safety valve. Roberts notes as much in his introduction, but then, somehow, the safety valve doesn’t come up in the ensuing conversation. The interview is still well worth a read, but it’s too bad that contentious, but central element of the cap-and-trade legislation was once more overlooked, especially given the intense national interest in the gas-tax holiday.


Last month, Grumet sat on a panel in Washington, D.C., sponsored by the Society of Environmental Journalists, with representatives from the Clinton and McCain camps to “debate” the candidates’ green credentials. According to Darren Samuelsohn, who authored ClimateWire’s notable piece on the safety valve and attended the event, the subject of a mechanism to check runaway emissions prices did not come up. “It’s not been a factor in the presidential race,” Samuelsohn wrote in an e-mail. “Maybe when we get to the general, but it’s down in the weeds for the candidates for sure.”


Perhaps that would be different now, in the wake of the gas-tax debate-a reporter could very reasonably stand up and ask Clinton (assuming she stays in the race), “You support pricing mechanisms to bring down the cost of gas; would you support them to bring down the cost electricity?” And beyond that, what’s better-the simple, $12 safety valve ingrained in the Bingaman-Specter bill, or the Federal Reserve-like oversight board described in Lieberman-Warner? And what about other important facets of cap-and-trade: to what extent should credits be auctioned rather than allotted; should initial allotments to companies be based on their current emissions or the amount of electricity they produce; and how will the system play out in regulated versus unregulated electricity markets? Sooner or later we will have to know where the candidates stand.

Correction: An earlier version of this story mistakenly stated that Obama, Clinton and McCain all support the Lieberman-Warner climate bill. In fact, they all support some form of cap-and-trade legislation and only Clinton has specifically backed the Lieberman-Warner bill.

Curtis Brainard is the editor of The Observatory, CJR's online critique of science and environment reporting. Follow him on Twitter @cbrainard.