In the coming few decades, the world is facing three related problems.
First, agriculture contributes to climate change to a considerable extent. In its Fifth Assessment Report, the IPCC's Working Group III concludes that the AFOLU sector (agriculture, forestry and other land use) is responsible for just under a quarter (∼10 – 12 GtCO2eq/yr) of anthropogenic GHG emissions. Usually, a distinction is made between non-CO2 emissions, in particular methane (NH4) emitted by livestock and rice cultivation, and nitrous oxide (N2O) caused by the use of synthetic fertilizers and the application of manure on soils and pasture. Methane and Nitrous oxide have 25 times and 300 times stronger impact on the climate than CO2 respectively. CO2 emissions from agriculture are mainly caused by deforestation and peatland drainage. Emissions from agriculture have been rising on a yearly basis since 1990, although with important regional differences (they went down in Europe and up in Asia).