"It's not our long-term solution because of the competition with feed, and fuel competition, but it is prompting us to put into place a refueling infrastructure that could be used with cellulosic ethanol, " made from other types of plant material such as timber waste or switch grass.

CNN: Ethanol: Is it friend or foe?

But snubbing Islamabad, especially given Washington's historical support, would have been an insult that could fuel Pakistan's sense of isolation, feed its paranoia about India, and strengthen the hands of its anti-democratic elements.

CNN: Delicate Diplomacy

One of his projects has been to create a coalition of governments, corporations and non-profits to develop cheap, hygienic cooking stoves for the millions of women around the world who have to forage for fuel to feed their families.

ECONOMIST: American diplomacy

Tourism is creating other problems for the local environment, too, including increased population density, over-dependence on wood as a fuel and construction source and the overgrazing and cutting of mountain slopes to feed livestock.

BBC: Everest's growing problem

American farmers and ranchers are proud to grow the food, feed, fuel, and fiber that enhance our national security and prosperity, and remain steadfast stewards of the land they love.

WHITEHOUSE: The White House

But much of the cynicism is centered on corn-based ethanol that some consider not just an inefficient fuel source but also one that also creates food shortages, driving up the cost of feed for livestock producers.

FORBES: Can Ethanol Cut Foreign Oil Imports?