Phil's explosive picture sums up exactly what I was trying to say about the methane problem. Dont strike any matches beside a cow near you today!
Ross makes a fair point there but on the grand scale of things, and in general terms, the poor ould cow in the field has grazed away merrily for a thousand years, has provided us with milk and meat and butter and added to the nice pictorial landscape. We are in danger of getting silly on the green issue. It's also becoming something of an unfortunate marketing tool. My company is greener than yours!..kind of thing.