Well, the Keystone XL pipeline was delayed, to much applause from environmentalists and local farmers. The supporters of oil tube claim we've just thrown away a hefty number of jobs. Both sides have a point here, and quite frankly, neither is wrong. If you're sane, you can't really argue against environmentalists (I mean their overarching goals, not their means of implementation). And yes, this pipeline would have created jobs, at a juncture when said jobs are quite badly needed.
Let me clarify the point about environmentalists. Perhaps we all don't advocate attacking tune fishing ships in the middle of the Atlantic Ocean, but most of us agree that we should be vigilant about "protecting the Earth" and the climate change is a real issue that needs to be contended with. Just because most of us (sane) people agree with those claims, doesn't mean we're all environmentalists, or, more specifically, that we were all overjoyed at the blocking of this pipeline. So, why not?
This is all about ideology, not science. There's no point in discussing the critics who refute the science, since they probably don't believe in evolution either, and they're idiots. But there is a "time-horizon" difference in ideologies that does create this gap. In a gross generalization, I'll say that the environmentalists among us have a rather far-reaching view of the world. Their concerns lie in "tomorrow and after." What will the natural state of the planet be like in 50 years? This is a good question, and if the answer doesn't look so appealing, then yes, it's time we took measures to better the world. The critics take a much more "here today" viewpoint (another generalization). Mostly, their favorite tune is, "The costs of implementing too many pro-environmentalist changes are too high. We'll be hurting people NOW." (E.g.- No jobs from the pipeline).
I agree with the blocking, in this case. Being of a liberal bend, I'm all for protecting the environment whenever possible. And, from an economic point of view, I don't think sustained job growth comes from one-off projects like the pipeline. I do, however, get surprised when people on both sides of this argument appear to be dumbfounded by the fact that there is any opposition to their viewpoints. This battle over climate change has become so vicious and has involved so much teeth-gnashing, that at this point compromise seems very difficult to foresee.