Each day human impacts on global warming and their consequences are more evident (see Gillett et al. 2008). Specifically, methane and nitrous oxide are gases with high effects on global warming (ISAT-GTZ 2000, Gillett et al. 2008). The amount of emissions of these gases from agricultural systems comprises about 33 % of the global release of methane and nitrous oxide (ISAT-GTZ 2000). In this case study, some issues will be discussed with methane and nitrous oxide gases from agriculture and the use of biogas as an alternative to mitigate the impacts of these gases.(see Chip's assignment)

Methane: The reduction of one kilogram methane is equivalent to the reduction of 25 kg CO₂ (ISAT-GTZ 2000). The capture of methane plus its energy result in the elimination of ~13.24 Mil t CH₄/year worldwide (ISAT-GTZ 2000). Additionally, if fossil fuels and firewood are replaced by biogas additional CO₂ emissions can be avoided. Including all these effects, with an adequate management of the methane produced by agriculture ~420 Mil t of worldwide CO₂ could be avoided (ISAT-GTZ 2000).

Nitrous oxide: The relative climatic change potential of nitrous oxide is up to 320 times higher than CO₂ (ISAT-GTZ 2000).  Only a reduction of 10% of N₂O from agricultural systems can be assumed by anaerobic treatments (ISAT-GTZ 2000). However, this means that 49,000 t N₂O/year or 15.7 Mil t CO₂-equivalents could be reduced on average (ISAT-GTZ 2000).

          Biogas has huge energy potential. For example, the ISAT and GTZ (2000) illustrate that the energy of one m³ of biogas is equivalent to the energy values of: 0.5 kg of diesel, 1.3 kg of wood, 0.7 kg of hard coal, and 0.24 m³ of propane. Similarly, Botero (2007) in one evaluation of one swine farm in Costa Rica calculated that this farm with 10,000 pigs could produce 800 m³ of biogas per day. This biogas has the potential to produce 500 KWH per day or 182,500 KWH per year (Botero 2007). In this case, the generation of energy from biogas could generate an economic benefit for the farm of $20,075 per year. This case shows how the capture and use of biogas in agricultural systems improve the efficiency of the system, generates economic benefits, and reduces environmental pollution.