c sequestion
the theory is we can burn as much coal and oil as we want. as long as we sequester the carbon into the ground instead of releasing it into the atmosphere. unfortunately reality often differs from theory. the technology for sequestering carbon is going to be much more expensive than was previously assumed. if it's even possible at all. apparently injecting carbon dioxide into the ground changes the ph. which dissolves limestone. which releases twice as much carbon dioxide as you tried to sequester. sigh. the number of suitable sites for long term storage of carbon is actually quite small. the volume of carbon that can be sequestered is disappointingly low.