If we do nothing, we still get to a post-carbon future, but it will be bleak. However, if we plan the transition, we can have a world that supports r… - Richard Heinberg

Fossil fuels enabled a dramatic expansion of energy usable by humanity, in turn enabling unprecedented growth in human population, economic activity, and material consumption.

Using science, technology, and cheap energy, we expanded farmlands, chain-sawed forests, exploited fisheries, mined minerals, pumped oil, and flattened mountains for their buried coal. And we did these things in a way that was not remotely sustainable. By harvesting renewable resources faster than they could regrow, by using non-renewable resources that could not be recycled, and by choking environments with industrial wastes, we were borrowing from future generations and from other species.

During the last 200 years, per capita energy usage grew eight-fold, while human population expanded at about the same rate. As a result of energy growth, all the things we do with energy became more doable. Transportation, manufacturing, agriculture, and mining exploded in scale. Energy became so abundant that it seemed we could solve any human problem, now or in the future, just by throwing more energy at it. We even reconfigured our economic system so that it assumes and requires perpetual growth. But growth in fossil-fuel energy can’t continue much longer: depletion and climate change will see to that. And even if we make a wholehearted effort to switch to low-carbon energy sources, we face limits to nature’s supplies of materials with which to make solar panels, wind turbines, nuclear reactors, and batteries.