You’re an environmental activist, and President Obama has finally catapulted global warming into the top tier of national issues after four years of near-silence. What do you do?

In Obama’s second inaugural address, perhaps the most prominent speech of his second term, the president promised to “respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations.” More specifics are certain to come soon in the State of the Union Address. Now, then, is your time to press for big, creative policy that will demonstrate to other nations that America will cut its carbon dioxide emissions, if they will, too.

You could also declare war over a near-irrelevant side issue.

Yes, certain environmental groups seem determined to waste more time generating gratuitous and distracting strife over the Keystone XL oil pipeline. Over the last few days, signs advertising a big anti-Keystone XL rally in February have been pasted up all over Washington. Following Obama’s Monday speech, Environment America’s Margie Alt said that the president must first reject the pipeline if he is to make climate change “a central priority.” Sierra Club Executive Director Michael Brune even said that, in the fight against Keystone XL, his storied organization is willing to commit acts of “civil disobedience” despite its ban on such tactics.

But trying to reduce national or global emissions by blocking an oil pipeline or two is like trying to hold back the sea by sticking fingers in a leaky dike. If Keystone XL’s 700,000-800,000 barrel per day capacity didn’t come online, Canada could still export a few million barrels a day just with existing pipelines. Canadian oil firms would also build others that run to their west coast. And if that didn’t work, they would expand existing ones. And if that didn’t work, they would increase the use of trains to transport their crude, as they already have. There is even talk of moving crude east to the St. Lawrence seaway. There are doubtless many more options that motivated Canadian energy companies could devise. As long as there is high world demand for crude at prices that make it economically viable to extract from Canada’s “tar sands,” lots of supply will find its way to buyers.

If the future of the climate really hinged on a Canadian oil pipeline or two, Alt, Brune and like-minded others might still have a case. But it doesn’t. The Council on Foreign Relations’ Michael Levi points out that the dire warnings circulating rely on absurd calculations — it would only be “game over” for the climate if we burned Canadian “tar sands” crude continuously well past the year 3000. On shorter timescales, Canadian unconventional oil is only 5 to 15 percent worse than conventional crude, and there is lots of pretty dirty oil from lots of other places we can and will burn well before clearing the Alberta tar sands.

The future of the climate hinges on policies and technologies that discourage demand for coal and oil, no matter where it’s from and no matter how it gets to market, either by making fossil fuels more expensive or clean sources of energy cheaper. Doing that without unduly harming human welfare — which, unfortunately, still depends on steady supplies of energy-dense, easily transportable hydrocarbons such as oil — requires a slow, managed transition, not the haphazard rejection of infrastructure.

If world governments successfully transition their countries off fossil fuels, eventually no more tar sands oil will come out of the ground, because no one will want it. So push for carbon taxes and demand energy efficiency requirements; get rid of fossil-fuel subsidies and invest in energy technology research; figure out how to bring China on board, not to mention Congress. These are things to march for.

Transferring national focus from real global warming policy is among the harmful effects of the anti-Keystone XL crusade. But most offensive is the implication that it is impossible to really care about global warming if you don’t want to kill the pipeline — that the president’s decision on the matter will be some sort of “test” of his desire to avoid the risks of pumping carbon dioxide into the atmosphere. In fact, it should be very easy for those of us who care about climate change to keep sight of the big picture, accepting that Keystone XL is just one of many pieces of energy infrastructure that will keep the oil flowing as long as we need so much of it, while working to ensure we don’t need so much of it for much longer.