What’s changed in the last few decades is the development of technologies that can effectively harness the diffuse, but decentralized and inexhaustible, energy in our environment.
Renewable energy sources are a step up, not a step down; instead of scarce, expensive, and polluting, they have the potential to be abundant, cheap, and globally distributed. Transitioning all of our infrastructural systems to be powered by renewable sources is about growing out the number of people who have access to more energy, who benefit from using it to meet human needs, whether as basic as cooking food or as modern as global telecommunications.
We live on a sun-drenched blue marble hanging in space, and for all that we persist in believing it’s the other way around, that means we have access to finite resources of matter but unlimited energy. We can learn to act accordingly.
We are living at the cusp of remaking ourselves from a primitive species that gets most of our energy from literally setting stuff on fire, and that just junks stuff when we’re done with it, into an species that fits harmoniously into a planetwide ecosystem, that uses energy from the sun, harnesses it for use and to fabricate what we need to thrive, and then returns those materials to the common pool to be used and shared again.