Abstract: Agricultural elements have been covered in the scenario process on shared socio-economic  pathways (SSPs) incompletely and pathways have not been specified for the future  development of the European Union. We will therefore devise a general framework on  European Representative Agricultural Pathways (EU-RAPs), where we cover different  aspects of agricultural development, as for example European and domestic agricultural and  environmental policies, or different livestock and crop management systems, and describe  future developments of the confederation of the countries of the European Union. For the  agricultural elements we distinguish between elements that can be derived from the  definitions in the Shared Socioeconomic Pathways, as for example irrigation efficiencies  which are linked to technological development, and elements that have to be newly devised  such as the development of the Common Agricultural Policy. For the future of the European  Union we develop five different worlds which correspond to the SSPs. Finally both  frameworks are combined.

Abstract: Livestock directly contribute to greenhouse gas (GHG) emissions mainly through methane (CH4) and nitrous oxide (N2O) emissions. For cost and practicality reasons, quantification of GHG has been through development of various types of mathematical models. This chapter addresses the utility and limitations of mathematical models used to estimate enteric CH4 emissions from livestock production. Models used in GHG quantification can be broadly classified into either empirical or mechanistic models. Empirical models might be easier to use because they require fewer input variables compared with mechanistic models. However, their applicability in assessing mitigation options such as dietary manipulation may be limited. The major driving variables identified for both types of models include feed intake, lipid and nonstructural carbohydrate content of the feed, and animal variables. Knowledge gaps identified in empirical modeling were that some of the assumptions might not be valid because of geographical location, health status of animals, genetic differences, or production type. In mechanistic modeling, errors related to estimating feed intake, stoichiometry of volatile fatty acid (VFA) production, and acidity of rumen contents are limitations that need further investigation. Model prediction uncertainty was also investigated, and, depending on the intensity and source of the prediction uncertainty, the mathematical model may inaccurately predict the observed values with more or less variability. In conclusion, although there are quantification tools available, global collaboration is required to come to a consensus on quantification protocols. This can be achieved through developing various types of models specific to region, animal, and production type using large global datasets developed through international collaboration.