Ruminants contribute to global greenhouse gas (GHG) emissions, principally as enteric methane (CH4) emissions. Direct selection for reduced CH4 emissions through combined selection for both low residual feed intake and methane yield could potentially provide a long term reduction in enteric methane production of 40-45%. If a methane-related trait were to be implemented by a livestock industry it will most likely be via genomic breeding values, which demand large numbers of measured animals in the reference population. Given the size of the reference population required for methane traits, it is imperative that wherever possible groups around the world collaborate on methodologies for measurement and collection of data. This has been the primary focus of the Animal Selection Genetics and Genomics Network (ASGGN) of the Livestock Research Group of the Global Research Alliance to reduce GHG emissions from agriculture.