Google+ Emission of Greenhouse Gases (GHGs) from Livestock Sector of Nepal


Emission of Greenhouse Gases (GHGs) from Livestock Sector of Nepal

by Yadav Sharma Bajagai

Intergovernmental panel on climate change (IPPC) has classified the sources of greenhouse gases into six major source categories (energy, industrial processes, solvent and other product use, agriculture, land-use change and forestry and waste) each of which has further been divided into several sub-categories. Livestock is one of the sub-groups of the sources of greenhouse gases under the agriculture group. Methane (CH4) from enteric fermentation and CH4 and nitrous oxide (N2O) from livestock manure management are two major greenhouse gases emitted from livestock sector.

Greenhouse gas inventory of the country from livestock sector has been prepared by using the Tier 1 emission estimation method of IPPC by using default emission factors for different categories of animals. The data has been assembled and analysed by using 2006 IPCC Software for National Greenhouse Gas Inventories version 1.96. 

Livestock sector of Nepal is responsible to emit 12,295 Gg of CO2 equivalent annually which is 23% of total national gross GHGs emission per annum in terms of CO2 equivalent. Buffalo are the largest source of greenhouse gases (mainly CH4) followed by cattle. Livestock sector produces 583 Gg of CH4 and 0.2 Gg of N2O annually. Ninety percent of CH4 is from enteric fermentation and 10 % is from manure management while total amount of N2O is from manure management. Share of buffalo, cattle, goat, sheep, pig and equine (horses, asses, mules etc) to produce enteric CH4 are 51.9%, 38.5%, 8.8%, 0.2% and 0.1% emitting 270.9 Gg, 201.0 Gg, 45.9 Gg, 4.0 Gg, 1.1 Gg and 0.5 Gg of CH4 respectively per annum. Likewise, buffalo, cattle, poultry, pig, goat, sheep and equine are responsible for emitting 24.5 Gg (41.6%), 16.8 Gg (28.5%), 10.7 Gg (18.2%), 5.1 Gg (8.7%), 1.7 Gg (2.8%), 0.1 Gg (0.2%) and 0.04 Gg (0.1%) of CH4 from manure management. 

Above mentioned quantity of Greenhouse Gases (GHGS) is equivalent to one of the following statements

  • Annual greenhouse gas emissions from 2,410,872   passenger vehicles
  • CO2 emissions from 1,378,413,105 gallons of gasoline consumed
  • CO2 emissions from 28,594,058 barrels of oil consumed
  • CO2 emissions from 162,166   tanker trucks’ worth of gasoline
  • CO2 emissions from the electricity use of 1,533,098   homes for one year
  • CO2 emissions from the energy use of 1,064,541   homes for one year
  • Carbon sequestered by 315,267,818   tree seedlings grown for 10 years
  • Carbon sequestered annually by 2,621,630 acres of pine or fir forests
  • Carbon sequestered annually by 121,809 acres of forest preserved from deforestation
  • CO2 emissions from 512,310,204   propane cylinders used for home barbeques
  • CO2 emissions from burning 66,950   railcars’ worth of coal
  • Greenhouse gas emissions avoided by recycling 4,284,127 tons of waste instead of sending it to the landfill
  • Annual CO2 emissions of 2.9 coal fired power plants

Application of higher level methods (Tier 2 or 3) is suggested to estimate the enteric CH4 emission from buffalo and cattle as these categories of animals are found significant according to the rule of thumb of IPPC.

Improving the productivity of animals through better nutrition, health, management and breeding is the most feasible mitigation strategy in Nepal to reduce the emission of GHGs from the livestock sector. Increased productivity of livestock reduces GHGs emission per unit animal products (milk, meat etc.) and thus helps to reduce total GHGs emission either by reducing the number of animals or by reducing rate of increase in livestock population. Similarly, there are several other strategies studied which manipulate the enteric fermentation to reduce the production of enteric CH4. Enteric CH4 production can be reduced either by inhibiting archaeal methanogens or by in vivo oxidation of methane by using methanotrophs. In addition, reducing the availability of H2, which is the principal precursor for enteric CH4 formation, to methanogens either by reducing H2 production or finding alternative H2 sinks is another potential strategy to mitigate GHGs emission from livestock. Phytochemicals present in native plants could be significant agents to manipulate enteric fermentation resulting reduced GHGs emissions. Likewise, emission of N2O from livestock sector can be reduced by following good management practices in the farm and improving housing and manure management.