"The Market response to global warming and oil shortages is to use food for fuel"Don't think that's entirely true, Les.
The market's response to global warming is to offer "carbon offsets" for the terminally guilt-ridden.
The market's response to oil shortages (more strictly, to the increased prices which are only partially due to shortages) is to open new fields which were previously uneconomic (or exploit tar-sands ditto).
The market's response to subsidies on bio-fuel is to use food for fuel, but subsidies are the cause, not the market.