President Barack Obama speaks on climate change at Georgetown University on June 25. REUTERS/Larry Downing Today, President Barack Obama laid out an aggressive regulatory agenda to reduce carbon emissions, most of which won't require any approval from Congress.

Now, Republicans have two options.

They can respond to his plan with maximum political and legal resistance. This strategy comes intuitively to Republicans, and the conservative base would like it.

According to an April Gallup poll, 64% of Republicans think the threat of global warming is overstated and only 18% think it will pose a serious threat to themselves in their lifetimes.

But it's not likely to be an effective strategy for shaping policy. Obama is acting under legal authority he already has and a Supreme Court decision that forces the EPA to regulate carbon.

Republicans should instead do something they're not used to: Work with Obama to come up with a better alternative to his plan.

Obama has only taken a heavy-handed regulatory approach because that's what he can do without congressional action; if Republicans would agree to a carbon tax or a cap-and-trade system, he'd gladly take that over the plan he laid out today.

The R Street Institute has been a lonely but relentless conservative voice on this issue. Senior Fellow Andrew Moylan wrote today:

Regardless of one’s views on climate change, the simple reality is that federal policy is going to address the matter. That can happen through ill-advised regulations, like those proposed by the President today, or it can happen through a vibrant market with clear price signals attached to all fuels. Conservatives should seize the opportunity to once again emphasize the superiority of free markets over central planning.

He's right. But if the health care fight is any guide, Republicans are not likely to listen.

The Republican strategy of total resistance to health care reform led to a bill passing only with Democratic votes. That meant a bill that was less market-oriented than it would have been with Republican input.

Obama also had to buy off more constituencies than he would have needed with a broader coalition, so the bill contained costly accommodations to doctors, hospitals, pharmaceutical companies and more. If Republicans had played ball, we would have gotten a health bill that was both more aligned with conservative ideas and substantively better.

Of course, conservatives don't like to hear this observation: pointing it out is what got David Frum fired from the American Enterprise Institute. Three years after passage, Republicans still haven't come to terms with the fact that Obamacare is the law.

They shouldn't make the same mistake with climate change. But they probably will.