Energy is a natural resource and, for the most part, finite. Exhaustion of fossil fuels (coal, oil, and natural gas) is not imminent, although we may be at the onset of negotiating a slippery slope with regard to oil production. Interestingly, we have a history of responding to finite natural resources in danger of exhaustion. We exhausted forests in Europe at the start of the Industrial Age in our quest for making glass and metals, and we nearly drove whales to the point of extinction during the nineteenth century in our quest for whale oil. Fortunately, we found ways to avert what could have been a terminal crisis. The forests in Europe were saved from the axe by the discovery of coal as an alternative to wood in glass-and metal-making. Whales were saved from extinction by finding an alternative source for their oil for lighting in the form of kerosene. In the twentieth century we took effective action to rejuvenate a threatened species of marine animal life, but at the same time we discovered the technology to strip-mine the open oceans of fish life. As we exhaust open-ocean fishing, an alternative has been found in aquaculture or fish farming. Aquaculture is similar to relying on sustainable biofuels whereas open-ocean fishing, when fish are caught faster than they can reproduce, is similar to exhausting fossil fuels.