From burping cows and food miles to greenhouse gases
The global livestock population is at an all-time high of 28 billion animals, and animal agriculture is the highest source of greenhouse gases methane and nitrous oxide.
The amount of methane produced by livestock farming is predicted to rise by 60 percent over the next 11 years, which could be catastrophic for combating climate change. So what changes should we make to our eating habits?
David Shukman reports.