> they are by far and away one of the largest contributors to greenhouse gasses as a group Not sure what you mean by "group", but animal agriculture beats all

> they are by far and away one of the largest contributors to greenhouse gasses as a group Not sure what you mean by "group", but animal agriculture beats all transportation (road, sea, air) combined when it comes to greenhouse gases and the greenhouse effect. There are a few different sources from the UN on this (plus some other sources with even higher numbers).