They seem to be aware of the size of the problem, but are unable or unprepared to take a holistic approach to finding solutions and instead have decided to blame cattle for everything.

I have a problem with statements claiming that some thing (e.g. cars, buildings) or system (e.g. food) is responsible for a certain portion of GHG emissions. People - in the decisions and choices we make - are responsible for nearly 100% of emissions. In the case of food, our decisions as to how we grow, process, distribute and consume it, and what we do with food waste, are responsible for emissions related to food. If we change these decisions, we change the emissions. We need to keep the focus on behaviors and choices. If we start by talking in those terms, we will get to the solutions faster.