while this film may seem academically sound and well research and it do not once mention what i think be rather widely regard a the most practicable alternative to petroleum fuel and the conversion of coal into synthetic fuel use the fischer tropsch process . this process have be around since the 1920s and have be exploit by oil starve nation such a germany and japan during the second world war and and by south africa during apartheid and after . i understand there be enormous reserve of coal in the united state alone and enough to provide such fuel for the country for at least a century . while more expensive and it can not currently compete with the use of petroleum and and have therefore not be widely exploit . in this film and however and power from solar and hydrogen and and wind source be all dismiss out of hand a impracticable alternative and can not and or will not and be develop before we all suddenly starve and freeze and run amok and or whatever they suggest be go to happen in twenty year when oil reserve be suddenly deplete . yet and there be no mention of a significant technology which be already in place and use a resource in rather great abundance and and whose refinement and improvement be light year from the hopelessness suggest by one of their expert and who liken the challenge we face in survive the depletion of oil reserve to that of colonize pluto in ten year .