If you are a true long-term investor, the time has come to change your entire frame of reference - to recognize that we now live in a different, more-constrained world in which the prices of our finite resources will rise and shortages will be common.
Accelerated demand from developing countries, especially China, has caused an unprecedented shift in the price structure of raw materials and finite resources: After 100 years or more of price declines, resource prices are now rising, and in the last eight years have undone, remarkably, the effects of the last 100-year decline!
The world is facing an unsustainable surge in demand. In fact, it's no longer just a question of "peak oil" - we're now facing a future of "peak everything." How we deal with this unsustainable surge is going to be the greatest challenge facing our species.