It's not what you eat, it's what you believe....
Today Yahoo had a link to a story on Science site Live Science has an article about how substituting chicken for beef can make more of a different than even buying locally. The conventional wisdom is that transportation is the primary cause of greenhouse gases related to food. However, production is seriously underestimated:
The production phase is responsible for 83 percent of the average U.S. household's greenhouse-gas burden with regard to food, while transportation accounts for only 11 percent, the new study found. The production of red meat, the researchers conclude, is almost 150 percent more greenhouse-gas-intensive than chicken or fish.
This has been the conventional wisdom, in the various diets for a hungry planet, the calculation is that the grain required to raise a cow for slaughter is many times what could be used to feed people directly. So forget the knowledge in the article is old hat, take a look at the comments. What is clear, is that the challenge is not the knowledge, it's the ability to consider new points of view.