As many have reported, climate change was conspicuously and completely absent from all four national debates in this election cycle, for first time since 1984. Here's Lloyd Bentsen and Dan Quayle discussing climate in 1988, in the famous "I knew Jack Kennedy" VP debate. Both the level of seriousness and the degree of agreement in 1988 are surprising (though the exchange is admittedly brief).
In 2012, climate isn't just absent from the debates - it's absent from the Republican platform (as Ray Kopp laments here), almost never mentioned by Democrats, and therefore outside the current political conversation. Climate's most significant political appearance this cycle was as a punchline - Romney's line that "President Obama promised to begin to slow the rise of the oceans… My promise is to help you and your family."
Regardless of how one feels about climate change and climate policy, their complete absence from political debate is bad for the country. But why is it the case? What's different about 2012 compared to every other cycle since 1984? I can think of four possible reasons. None of them are very good.
One reason is fatigue. Battles over cap-and-trade in 2009-10 were the culmination of decades-long policy debates on climate. That legislation failed, and the policy cycle needs some time to "reset" after the political fallout from those battles (remember Joe Manchin (D-WV) shooting the Waxman-Markey cap-and-trade bill). But 2010 was a long time ago in political terms. Memories are short. And while this might explain why climate is not a headline issue, it doesn't explain why it's gone away completely.
Another possibility is the sheer dominance of the economy as a political issue. But this also doesn't explain why climate doesn't appear among other B- or C-list issues like health care, education, or trade. This is particularly true in last night's debate, ostensibly focused on foreign policy. Major domestic issues are (or at least were supposed to be) off the table. And climate is fundamentally a foreign policy issue. International cooperation, especially with China, is critical. It's also a security issue - ask the Department of Defense. What's particularly shocking is how important energy was in the debate without any mention of climate at all.
A combination of these two might result in climate being ignored for political marketing reasons. It's much easier to criticize positions on climate than defend them. Democrats don't want to mention climate since Republicans will accuse them of damaging the economy. But Republicans don't want to bring it up either since, as John Krosnick's public opinion research suggests, support for long term action on climate is high. The result is neither side wants to make the first move. It's an odd equilibrium, but equilibrium nonetheless. Krosnick's research suggests it's based on misperceptions of public feelings on climate.
A slim possibility is that climate is less important because of the recent drop in US emissions - though that's perhaps giving the candidates too much credit. The President might be unwilling to discuss that drop because it is in part due to economic weakness on his watch. And Romney might be unwilling to discuss since it undermines his argument that US should expand fossil fuel use, especially coal. But I don't think this explains much. The energy policy community is still trying to understand recent trends in U.S. emissions. The wider policy community hasn't grasped this yet, much less politicians, speechwriters, and pundits.
All of these are more or less plausible reasons why climate is not a headline political issue. But none of them are adequate to justify its absence from the political conversation. Combinations of some or all of the above are likely, but still insufficient.
Ultimately, I think a big part of the blame falls on the media. When neither candidate finds it convenient to discuss a crucial issue, the role of the press as shapers of the political conversation compels them to raise that issue. Specialist energy/environment journalists (and a few wonkish generalists) are trying to do that, with little mainstream success. Major publications and commentators, including the debate moderators, have not. (David Brooks aside, though I can't tell if his recent piece is satire, senseless, or sneakily, sadly right).