Depends on how it's used. Fundamentally, peak $resource refers to the peak in production of $resource, which under laws of physics as we understand them will ne

Depends on how it's used. Fundamentally, peak $resource refers to the peak in production of $resource, which under laws of physics as we understand them will necessarily happen eventually. Barring changes in demand, $resource whose production has peaked will become more expensive; peak $resource implies peak cheap $resource in this case. Unfortunately, peak $resource has been used, reused, and abused in so many different ways that stating one way is the definitive is bound to be incorrect.