I must admit it’'s not super intuitive to me either, but it seems the consensus is pretty strong among experts, and I haven’t taken the time to really delve in deep on the issue.

But apparently a significant part of the problem is that cows make a lot of methane, that is a very bad greenhouse gas, and when it breaks down it’s to CO2 which is still a greenhouse gas. So kind of a bad double dip as I understand it.