We have lots and lots and lots of fuel, in part because rocket fuels are varied. Many of them can also be synthesized through the use of water, atmospheric gass

We have lots and lots and lots of fuel, in part because rocket fuels are varied. Many of them can also be synthesized through the use of water, atmospheric gasses, and power. For example, Blue Origin and SpaceX are developing launchers that run on methane - fantastically plentiful on Earth in the form of natural gas. Delta IV runs on hydrogen, which can be synthesized through gasification or electrolysis. Falcon 9 and Atlas V burn kerosene, also very common. The real issue is whether, at high launch rates, this will become a meaningful contributor to climate change; hopefully through use of space-based resources we can reduce the up-mass requirements enough to avoid that problem.