Peak oil has never been a popular theory among market analysts. After all, the peak has been prophesied repeatedly, but still hasn’t come to pass. Time after time, new areas have been opened to development and new technologies have come to the fore, putting off the peak for another day.

Yet the specter of peak oil has had beneficial consequences. In recent years, fears of peak oil energized efforts to improve efficiency and promote alternatives. The threat of peak oil was conflated with the risk of dangerous climate change, encouraging more people to support policies that tackle greenhouse gas emissions. Many of these actions were valuable even if their impetus was unsound: greater efficiency and more abundant alternatives are largely good economic and security news, and smart climate policies are good for the environment.

So perhaps we should be at least a little worried that booming U.S. oil production, along with discoveries elsewhere in the world, seems to be killing off the peak oil narrative. Don’t get me wrong: better understanding of our energy predicament is generally a good thing. But it’s difficult to escape the conclusion that there are some troubling wrinkles here. In particular, I’ve recently heard more than one European analyst emphasize how important the specter of peak oil was in pushing Europe to diversify its energy supplies and improve its energy efficiency. But now, they say, the shale oil boom has helped kill that meme. The upshot, they fear, is that interest in climate and efficiency policies -- some of which were foolish but many others of which were valuable -- are weakening.

To be certain, Europe may be an outlier. The fear of peak oil was never as much of a policy driver in the United States. And Chinese efforts to improve efficiency seem to have been driven more by basic economic and security concerns. Still it’s worth keeping an eye out for changes in the offing. If the stories from Europe are accurate, they’re a useful reminder that the consequences of the U.S. oil boom will be felt in all sorts of odd ways.