In environmental circles, there's definitely some discomfort with leading GOP contender John McCain on the subject of global warming.

Granted, we all know McCain has a strong history on the issue.

He was co-sponsor of the 2003 McCain-Lieberman legislation, a failed attempt to achieve a cap on U.S. carbon dioxide emissions. And there's no doubt that McCain is much more serious about taking mandatory action than other Republican hopefuls, like Rudy Giuliani and Mitt Romney—who has been bashing the Arizona senator repeatedly for being too strong on the climate issue.

But at the same time, while Democratic candidates like Hillary Clinton and Barack Obama have released detailed energy and climate policy proposals, you'll find nothing of the sort on McCain's official campaign website.

Instead there's just a brief snippet of text [7] explaining how McCain is the next Teddy Roosevelt, a green Republican, and saying of the Arizona senator, "He has offered common sense approaches to limit carbon emissions by harnessing market forces that will bring advanced technologies, such as nuclear energy, to the market faster, reduce our dependence on foreign supplies of energy, and see to it that America leads in a way that ensures all nations do their rightful share."

McCain's campaign website then goes on to talk about how we can "meet our obligation to be proper caretakers of creation." This is clearly a presentation geared towards Republican voters—rather than wonks who want to know precisely what a McCain presidency would mean for our most pressing environmental challenge.

Indeed, recently McCain got caught egregiously spinning [8] during the January 24 GOP debate. No kidding: He dared to suggest that a cap on emissions (which he supports) is something other than precisely that—a cap. The Straight Talk express crashed and burned that evening, and that's dismaying.

Nevertheless, if you look through the full record—and past the present, high-stakes political moment—it's still possible to reach a much more optimistic outlook about how a President McCain would presumably handle climate change.

Arguably the chief document in this regard (at least if we seek something recent—and before the political pressure of the primaries) is McCain's January 30, 2007 testimony [9] to the Senate Committee on Environment and Public Works on the subject.

In his Senate testimony, McCain outlined five broad principles that must characterize any policy to address global warming:

 

1. "rational, mandatory emission reduction targets and timetables"

2. "a market-based, economy wide 'cap and trade' system"

3. "mechanisms to minimize costs and work effectively with other markets"

4. "it must spur the development and deployment of advanced technology"

5. "it must facilitate international efforts to solve the problem"

McCain is strongly opposed to the "carbon tax" route. He's also a big supporter of nuclear energy—he thinks that given how much power it provides today it has to be part of any solution, though he acknowledges outstanding waste disposal issues. In fact, according to [10] the Washington Post, the failure to embrace nuclear power explicitly was a chief reason McCain did not add his name officially to the current, moderate and bipartisan Lieberman-Warner climate bill.

Nevertheless, McCain's outlook very much shares the spirit of that bill—he wants compromise, rather than trying to ram through a very ambitious policy very quickly. Above all, McCain preaches pragmatism on climate policy.

As he put it in another speech [11] at the Center for Strategic and International Studies:

 

The policy must include mechanisms to control costs and protect the economy. Just as there is danger in doing too little, there is peril in going too far, too fast, in a way that imposes unsustainable costs on the economy. I believe "cap and trade" is the best way to manage cost and maximize benefits, but we must look at other market-based means to give added assurance that our policies are an instrument of job creation, economic progress, and environmental problem solving.

So what's the upshot here? What would a McCain presidency really mean for our planet?

First, it's too bad that McCain has been spinning lately (presumably to protect himself from Romney), and that he hasn't laid out more explicitly a policy plan for addressing climate change if elected president. However, McCain's history on the issue ought to convince anyone that he's serious about taking action—and anyway, a policy plan outlined now may not be the best approach for the very different political context that will most assuredly exist in 2009.

Second, it seems unlikely that a McCain policy on climate will go as far as the policies proposed by the leading Democratic contenders, which call foran 80 percent reduction in emissions by 2050. Given his focus on cost containment and pragmatism, and his history of working with the very moderate (or even conservative) Joe Lieberman, we should expect that McCain would shy from so ambitious a target. And that's something that will make environmental groups somewhat less than ecstatic of his approach (although of course they'll still recognize that he's vastly better than Romney or Giuliani).

So where does that leave us?

There seem to me to be two fundamental points. One: Anyone who cares about global warming should want McCain to vanquish his Republican opponents in the primaries. If we get McCain versus one of the Democrats in the general election, we'll have two candidates who want strong action (even if their precise stances may differ). Whoever wins in that scenario, we'll be better off in the climate arena than ever before—and we can count on action finally happening.

The other fundamental point is this. While McCain's support of nuclear power and his more cautious approach to greenhouse gas regulation each can be criticized, neither rates, in my view, as an irredeemable flaw. Politics is too messy for purism on these matters—and the climate problem too urgent.

A McCain presidency would certainly be a great step forward on climate, and given our nation's past history on this issue, well…that's more than a start.