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Jeffrey S. Dukes, "Burning Buried Sunshine", 2003, gives an excellent breakdown on how coal, oil, and gas are formed, their energy equivalents in current biomass, and a few other odd bits. http://globalecology.stanford.edu/DGE/Dukes/Dukes_ClimChange... Yes, there's a lot of sunlight. But consider that 70% of it falls where you cannot walk, unless you carry your own cross, and much the rest of it is called on elsewhere in the ecosystem. That still leaves a great deal available to humans, but an order or two of magnitude less than that 1,000 times more than we need in a year. Plants are far closer to 1-3% efficient at converting sunlight to stored energy, so you're off by an order of magnitude there. I've scoped out the biomass equivalent acreage for US petroleum consumption under several scenarios, and it's not pretty. See the table about halfway down this page: https://www.reddit.com/r/dredmorbius/comments/2cvap7/the_int... Consider that much the world would like to be at US levels of energy consumption, and the population continues to increase. If you want to do some useful reading, start going through Vaclav Smil's books. Most ecology texts are also quite useful. Howard and Eugene Odum have written several excellent ones, both general to ecology, and specific to humans and energy. Keep in mind that energy is among our immediate problems, but is hardly the only one. |
However, even if you use 2% that's still easily 20x the energy from Oil. Also of note, we eat fish grown that eat fish... that eat plankton so we do capture energy from the oceans just really inefficiently.
Yes, this may seem pedantic but recreating a western style lifestyle is hard in very large part due to indirect energy costs for meat. Buildings, transportation, or manufacturing can be 10x efficient corn and thus cows not so much. Yes, ethanol takes 40% of corn but cows take 36% and some leftovers from ethanol.