No one knows what 40% of fossil fuels is. There is almost limitless methane...and more is created constantly. No one also knows what the potential for carbon sequestration is. That can also be enormous.
"There is almost limitless methane...and more is created constantly."
yes !
nature generates a lot of methane, nature always has generated a lot of methane and nature always will generated a lot of methane
this has be ongoing for billions of years, , organic material rots and creates methane
however methane atmospheric concentration is 0.00018 % >>> parts per billion
this is because methane gets oxidized into CO2, which is only 420 parts per million
that should be a clue for you that nature dominates over mankind's emissions
'the potential for carbon sequestration is. That can also be enormous.'
it would be enormously energy intensive, enormously expensive and very likely to be an enormous failure