The problem with meat!
“Collectively, the world’s livestock produce 10 per cent of all the greenhouse gases, including 25 per cent of the methane, among the most potent of all. Then there is water, which is rapidly becoming the greatest check on overall food productivity. It takes 500 litres to raise a kilo of potatoes; 900 for a kilo of wheat; nearly 2000 for rice or soya; 3500 for
a kilo of chicken; and a staggering 100,000 litres for a kilo of beef.” “…2 kilograms of feed for each kilogram of chicken, 4 for pork, and 7 or more for beef” The latter two quotes are from an article printed in New Scientist. While I take most things that Greenpeace say with a grain of salt, the New Scientist article and the Greenpeace article agree at least on the amount of feed required to produce a kilo of beef. Some more information on this topic can be found here.