RE: ethanol
Here is an interesting fact about oil:
In the past 140 years since oil has been used, about 1.1 trillion barrels of oil has been used. (1100 billion barrels)
This sounds like a huge amount of oil, but if you put all that oil into containers that measure 1 mile per side (a cubic mile), it would only fill 42 cubic miles. Much smaller number, just 42 containers of 1 cubic mile each.
Still sounds like a lot?
Well, if you spread all that oil over the entire surface of the Earth, how thick would resulting oil film be?
When you run all the numbers, it come out to be 0.0135 inch, thinner than 4 sheets of copier paper from your printer. Actually a single sheet of copier paper is 0.004" thick, so it is closer to the thickness of 3 sheets.
That not the amount of oil we use each year, it's the amount that has been used the last 140 years.