This paper focuses on the following areas: reducing methane emissions from ruminant animals (cattle, sheep) by modification of plant composition; reducing nitrous oxide emissions by making the use of nitrogen more efficient both in terms of going from soil to plant and in the animal; plant breeding may also enhance carbon sequestration in grasslands by focusing both on below ground traits of importance and on the composition of material returned to the soil as litter; and the processes involved in fertiliser production, particularly nitrogen fertilisers, result in considerable greenhouse gas