Well, as you might guess, I and pretty large contingent of scientists disagree mightily with that statement.
they add to the demand of scarce ariable land and water needed for food production and their impact WILL be negative on food costs, worldwide.
Reading the news, I can't agree with that. Because of the demand for corn to produce ethanol, farmers were reported as putting fields that weren't being farmed back into agricultural production. If there's such a demand for food crops, then why weren't those fields being farmed? Furthermore, the cost of oil to produce food crops has to be factored in. If the cost of oil goes up (which it's been doing for awhile) this affects both farming and transport (plane, train, truck, and ship). So energy is a major factor in food costs, and as oil prices stay high, they put pressure on food costs.
Finally, let me point out a broad area of agreement. Reducing our reliance on fossil fuels and fossil fuel imports will require a full spectrum of energy sources; there is no "be-all, end-all" solution (except maybe for controlled nuclear fusion - chuckle, laugh, guffaw, riotous laughter). Ethanol and biofuels address one sector, primarily vehicular transport.
“Well, as you might guess, I and pretty large contingent of scientists disagree mightily with that statement.”
That “pretty large contingent” is dominated more by “scientists” with no expertise whatsoever in climatology or any related scientists and among climatologists themselves there is no “consensus” regarding MAN-MADE GLOBAL WARMING and the only “majority” viewpoint of actual climatologists is that the man-made CO2 factor is not significant enough on any scale to be the driver of any current “warming trend”.
MAN-MADE GLOBAL WARMING is more political science than pure science.
As for “alternative fuels” themselves, they are based on another faulty premise - that the economics of demand for fossil fuels alone will neither improve the efficiency of THEIR use or the extent and efficiency of their supply and extraction. That fits fine with “peak oil” theory which has been proven consistently wrong.