A growing and increasingly influential movement of philosophers, ethicists, law professors and activists are convinced that the great moral struggle of our time will be for the rights of animals.
Anyway, in my writing I've always been interested in finding places to stand, and I've found it very useful to have a direct experience of what I'm writing about.
Corn is an efficient way to get energy calories off the land and soybeans are an efficient way of getting protein off the land, so we've designed a food system that produces a lot of cheap corn and soybeans resulting in a lot of cheap fast food.
Fairness forces you - even when you're writing a piece highly critical of, say, genetically modified food, as I have done - to make sure you represent the other side as extensively and as accurately as you possibly can.
For at the same time many people seem eager to extend the circle of our moral consideration to animals, in our factory farms and laboratories we are inflicting more suffering on more animals than at any time in history.
I have had the good fortune to see how my articles have directly benefited some farmers and helped build markets for their products in a way that preserves land from development. That makes me a hopeless optimist.
In addition to contributing to erosion, pollution, food poisoning, and the dead zone, corn requires huge amounts of fossil fuel - it takes a half gallon of fossil fuel to produce a bushel of corn.
In corn, I think I've found the key to the American food chain. If you look at a fast-food meal, a McDonald's meal, virtually all the carbon in it - and what we eat is mostly carbon - comes from corn.
In general, science journalism concerns itself with what has been published in a handful of peer-reviewed journals - Nature, Cell, The New England Journal of Medicine - which set the agenda.
Now that I know how supermarket meat is made, I regard eating it as a somewhat risky proposition. I know how those animals live and what's on their hides when they go to slaughter, so I don't buy industrial meat.