This book envisions a future in which humans have destroyed the planet through chemical emissions and radiation. The ‘Alternative Energy Source’ century probably refers to a time when people were forced to look for alternative energy sources because fossil fuels had run out (a situation looming in our own not too distant future). The mention of radiation suggests that one of the solutions followed was nuclear power. Nuclear power stations provide energy from nuclear fission (splitting the nucleus of an atom). Nuclear power is used today, but its safety is hotly debated. Nuclear stations produce nuclear waste that remains radioactive for a very long time, and so requires permanent and safe storage. If this nuclear waste leaks or is not stored responsibly it can be very dangerous to humans, animals and the environment. Serious nuclear power plant accidents have also occurred, releasing huge amounts of dangerous radiation into the atmosphere. Rick also refers to ‘Old World chemicals,’ which are most likely the chemical emissions released from coal power plants, cars, factories and other sources of pollution today. These all have damaging effects on the environment, and will cause many problems for future generations unless they are reduced. The world that Rick lives in is not an unbelievable future for our own world.