Due to my background in physics, I like to think of things in terms of energy. At the moment our energy comes from two main sources: nuclear energy and solar energy. “What about coal, oil, and other fossil fuels?” Let me explain.
I’m considering solar energy every energy source who’s origin is our friendly sun. Energy from solar panels is obvious. Less obvious is wind energy. But our sun is providing the heating differential that drive those climate patterns and resulting wind. Hydroelectric power? Also caused by evaporation and later precipitation due to the sun’s heat. The sun does the work to take water from the ocean and place it in our mountainous regions. We harness the energy from that water as it travels back to the seas. Coal and oil are merely forms of solar energy captured by plant and animal life from millions of years ago sequestered by our earth. Photosynthesis allowed the plants to grow and the swamps and forests later got buried and became oil and coal. We’re merely utilizing this ancient reserve of energy to fuel our cars and power plants today. But, the energy’s origin is still solar.
Nuclear decay is also a great source of energy. It’s what is keeping the inside of our planet molten, and provides geothermal energy for a few locations on the planet. If we concentrate nuclear isotopes, we can generate nuclear energy in a more controlled fashion. But, it’s still essentially heating water and using the resulting steam to turn turbines.
For billions of years our planet has been storing solar energy (very inefficiently I might add) in the form of fossil fuels. In the past few hundred years we’ve learned to harness those vast resources of energy. And we’re depleting those energy stores at an amazing rate. Oil companies are constantly on the search for new reserves of energy, as the old wells are drying up. Eventually, and it could be 100-200 years, we will have to go back to getting almost all of our energy from the sun again. This change can be slow and gradual, or sudden and catastrophic, that’s up to us. But the change MUST happen, for the simple reason that there is not an infinite amount of oil and gas on this planet.