Here's an intriguing story to kick off the new year with a little retrospection...

Flash back to 2008, and nearly all of the top GOP contenders for a 2012 presidential run were taking global warming pretty seriously and offering real, if measured, endorsements of Congressional or state action to curb pollution and GHGs.

On the campaign stump, in books, speeches and nationally-televised commercials, aspiring GOP White House candidates such as Tim Pawlenty, Mike Huckabee and Mitt Romney have warned in recent years about the threats from climate change and pledged to limit greenhouse gases. Some have even committed the ultimate sin, endorsing the controversial cap-and-trade concept that was eventually branded “cap and tax.”

Back in 2008, Newt Gingrich took to a couch next to the Right's current-day arch-nemesis, Nancy Pelosi, to endorse Congressional climate action in an ad sponsored by Al Gore's Alliance for Climate Protection.

And as Politico notes, even Sarah Palin has flip flopped on the issue:

Just days after McCain picked her as his running mate, Palin told ABC News she believes human activities "certainly can be contributing to the issue of global warming, climate change" and that "we’ve got to do something about it, and we have to make sure that we’re doing all we can to cut down on pollution."

Politico's Darren Samuelsohn calls it the McCain effect, with John McCain's prominent endorsement of cap and trade legislation making it safe for GOPers to talk about climate.

"I think McCain is moving in a responsible direction," then-House Minority Leader John Boehner (R-Ohio) told E&E News in May 2008. "Clearly the issue of climate change is on the minds of a lot of people. Humans clearly contribute to this. It just really depends on what kind of a cap-and-trade system, what kind of safety valves are in there."

Flash forward just a few years and each of these prominent GOPers are likely running for an excuse, a mea culpa, or another way to distance themselves from green records that are now liabilities with a Republican base strongly influenced by the Tea Party movement.

So what happened? Was it simply the polarizing direction of the cap and trade debate? The shift in the economic winds? The rise of the Tea Party? The inherent politics of a proposal centered on making our current base of energy sources more expensive, rather than making the cleaner alternatives cheaper?

Whatever the constellation of causes, the change is quite stark. Looking ahead to 2011 and beyond, can we build a new and enduring consensus around an innovation-centered approach to energy reform, building a clean economy, and responsibly reducing pollution? And can we make it sustained enough to avoid the factors that turned the endorsements of prominent GOP leaders into liabilities just a few years later?

We welcome thoughts from readers...