Dr David Johansson and Dr Fredrik Hedenus note that many sources of methane are non-point emission sources. This makes it harder to regulate and control methane emissions than most carbon dioxide emissions. The most important single sector emitting methane is livestock production, and the technical measures available to reduce emissions from livestock are small. The combination of being a non-point emission source and having few technical abatement measures implies that output based policies may be appropriate policies for reducing these emissions. Their back of the envelope estimates point to a benefit-cost ratio of about 2 of having a beef meat tax of US$ 1 in OECD countries. This would reduce global emissions by 30 to 70 M ton CO2 equivalents per year using GWP calculated over 100 years.