Yeah, an idyllic vision but totally naive, ignoring orders of magnitude.
Right here (
http://www.amisdelaterre40.fr/spip/spip.php?article230 ) Friends of the Earth's analysis of methanisation applied on a somewhat more realistic scale (but far from covering a significant part of the needs) in Germany; there is a long way to go.
So, yes, biomethanation is a possible path, or liquid biofuels, but it is far from being the miracle solution presented by this petition; it is at most a way to supplement at the margin an energy mix, perhaps for some specific needs ... with nuisances and limits well pointed by Friends of the Earth, little suspected of being nuclear and anti -environmentalists...
Moreover, to avoid locking ourselves into false debates, would it be so difficult to recognize that a decarbonated energy transition will inevitably lead to a global mix composed of all low GHG emitting energies, developed in a differentiated way according to the geographical situations and climatic. There is no universal miracle solution, and personally, I have no problem to assert that solar is perfectly valid in the tropics and wind in countries regularly wind, that the possibilities of hydropower are still largely untapped in Asia, Africa and America (but not in Europe), and that nuclear is an obvious solution for countries lacking other resources. But all these sources of energy have disadvantages (
all), and it is advisable to make your choices according to the local availabilities ...
Nobody has ever affirmed that nuclear power should constitute, everywhere, the only source of energy (in France, despite some imprudent assertions, nuclear energy represents only 20% of the energy consumed); on the other hand, it would ideally replace coal and some of the hydrocarbons.
The obvious benefits that a thorium-salt-salts sector would bring in terms of safety, drastic reduction of waste and sustainability of the resource (several millennia) are enough to make nuclear acceptable to those who are violently opposed to it? I have some doubts in view of the irrational dose inherent in these debates, but as global warming is more pressing, and fuel resources running out, we may think that the need will be law ... Much to prepare the future...
nb This debate has been focused on thorium, but a breeder station with molten salt breeder can burn uranium238, whose stock in France reaches several hundred thousand tons (several millennia without importation or mining); it's a little less virtuous than thorium, but it's interesting anyway ...