Today Slate answers the age old riddle of which milk/"milk" is better for the planet: soy vs. regular.
The answer may not surprise you. Or it may surprise you!
Soy milk, basically!
But the catch is that they're made really differently and thus difficult to compare. Cows require a huge amount of energy to raise, but the process of getting milk from the cow to the store isn't actually that complicated, whereas the process of actually making soy milk is fairly complicated, but there aren't any giant farting animals to take care of.
Cows: 14 calories of fossil fuel to produce 1 calorie of milk protein.
Soy beans: 0.26 calories of fossil fuel to produce 1 calorie of soybean.