activities causing global warming include burning fuels, increased industrial
emissions, cutting down forest, nuclear explosions, changes in land-use and land
management practices that have led to drastic changes in the atmospheric composition of the Earth and by taking part in other activities that release certain heat
trapping gases, i.e. green house gases (GHG) into atmosphere. Along with this,
agriculture is also playing a vital role in this global warming and in agriculture,
ruminants are among the worst offenders as they produce some gases that aid in
global warming. Intergovernmental Panel on Climate Change (IPPC) included six
gases namely, carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O),
hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride
(SF 6 ), which have high global warming potential.
The Earth would have been 4 °C colder than its normal temperature, if the
greenhouse gases were absent in the Earth’s temperature. So these GHGs may be
conferred as a necessary evil. CO 2 , CH 4 and N 2 O are present in the atmosphere and
are also produced as a result of agricultural and livestock and also from the
activities of the human beings. The global warming potential of CH 4 , N 2 O is 23 and
296 times higher with respect to carbon dioxide in global warming, respectively
(IPCC 2001). Anthropogenic gases like water vapour, CO 2 , CH 4 and Ozone contribute 36–72, 9–26, 4–9 and 3–7 %, respectively, to the global warming (Kiehl
et al. 1997).
2 Agriculture and Global Warming
Agriculture sector emitted 334.41 million tonnes of CO 2 equivalent, of which
13.76 million tonnes is CH 4 and 0.15 million tonnes is N 2 O. Enteric fermentation
constituted 63 % of the total CO 2 equivalent emissions from this sector, 21 % of the
emissions were from rice cultivation. Crop soils emitted 13 % of the total CO 2
equivalent emission from agriculture. Rest 2.7 % of the emissions is attributed to
livestock manure management and burning of crop residue. India emitted 3.3 million tonnes of CH 4 in 2007 from 43.62 million ha cultivated for this purpose. Of the
total rice area cultivated, 52.6 % was irrigated, 32.4 % was rain-fed lowland, 12 %
was rain-fed upland and 3 % was deep water rice (Huke at el. 1997). The annual
amount of CH 4 emitted from a given area of rice is a function of the crop duration,
water regimes and organic soil amendments. The CH 4 emissions from rice cultivation have been estimated by multiplying the seasonal emission factors by the
annual harvested areas. The total annual emissions are equal to the sum of emissions from each subunit of harvested area using the following equation. Global
warming, in turn, leads to regional changes in climate related parameters such as
rainfall, soil moisture and sea level. The extensive and frequent occurrence of
climatic extremes such as droughts, heat and floods in the last decade in many parts
Impact of Ruminants on Global Warming: Indian and Global Context
85
emissions, cutting down forest, nuclear explosions, changes in land-use and land
management practices that have led to drastic changes in the atmospheric composition of the Earth and by taking part in other activities that release certain heat
trapping gases, i.e. green house gases (GHG) into atmosphere. Along with this,
agriculture is also playing a vital role in this global warming and in agriculture,
ruminants are among the worst offenders as they produce some gases that aid in
global warming. Intergovernmental Panel on Climate Change (IPPC) included six
gases namely, carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O),
hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride
(SF 6 ), which have high global warming potential.
The Earth would have been 4 °C colder than its normal temperature, if the
greenhouse gases were absent in the Earth’s temperature. So these GHGs may be
conferred as a necessary evil. CO 2 , CH 4 and N 2 O are present in the atmosphere and
are also produced as a result of agricultural and livestock and also from the
activities of the human beings. The global warming potential of CH 4 , N 2 O is 23 and
296 times higher with respect to carbon dioxide in global warming, respectively
(IPCC 2001). Anthropogenic gases like water vapour, CO 2 , CH 4 and Ozone contribute 36–72, 9–26, 4–9 and 3–7 %, respectively, to the global warming (Kiehl
et al. 1997).
2 Agriculture and Global Warming
Agriculture sector emitted 334.41 million tonnes of CO 2 equivalent, of which
13.76 million tonnes is CH 4 and 0.15 million tonnes is N 2 O. Enteric fermentation
constituted 63 % of the total CO 2 equivalent emissions from this sector, 21 % of the
emissions were from rice cultivation. Crop soils emitted 13 % of the total CO 2
equivalent emission from agriculture. Rest 2.7 % of the emissions is attributed to
livestock manure management and burning of crop residue. India emitted 3.3 million tonnes of CH 4 in 2007 from 43.62 million ha cultivated for this purpose. Of the
total rice area cultivated, 52.6 % was irrigated, 32.4 % was rain-fed lowland, 12 %
was rain-fed upland and 3 % was deep water rice (Huke at el. 1997). The annual
amount of CH 4 emitted from a given area of rice is a function of the crop duration,
water regimes and organic soil amendments. The CH 4 emissions from rice cultivation have been estimated by multiplying the seasonal emission factors by the
annual harvested areas. The total annual emissions are equal to the sum of emissions from each subunit of harvested area using the following equation. Global
warming, in turn, leads to regional changes in climate related parameters such as
rainfall, soil moisture and sea level. The extensive and frequent occurrence of
climatic extremes such as droughts, heat and floods in the last decade in many parts
Impact of Ruminants on Global Warming: Indian and Global Context
85