My family and I decided to replace the furnace in our house, one that burned natural gas, with an electric heat pump system. We also installed a solar photovoltaic system including an array of solar modules or panels on our roof. In that way, we could generate most of the electricity used by our house from renewable solar energy. Weaning the entire world from fossil fuels, however, is a staggeringly complex and difficult task. Imagining a better world for tomorrow is relatively easy. Getting to that better world, starting from the existing world of today, is not easy at all. Vaclav Smil, in his 2022 book How the World Really Works: A Scientist’s Guide to Our Past, Present and Future, makes the case that this task will require immense changes in many areas where fossil fuels are now vital to the production of massive amounts of materials indispensable to modern civilization. Smil calls ammonia, steel, concrete, and plastics, “the four pillars of modern civilization.” All four pillars require very large amounts of fossil fuels to produce. Smil estimates that completing the transition of weaning the world from fossil fuels will likely take several decades or even longer.