Climate Change and Agriculture


#### Table 4.

State-wise livestock category-wise CH4 emission, Gg year<sup>1</sup> in the year 2012.

As there are significant variations in terms of livestock populations up to district level, CH4 emission pattern also shows wide variations in India as shown in Figure 3. Banas Kantha, Gujarat (112 Gg CH4); Paschim Medinipur, West Bengal (103 Gg CH4); and Jaipur, Rajasthan (102 Gg CH4) are top three districts in terms of livestock-related CH4 emission. Furthermore, out of the total 15.3 Tg CH4 emission in India, about 50% of the emission is contributed by 153 districts alone out of total 649 total districts. Within 153 districts, of the 4 livestock groups, maximum CH4 emission (more than 50%) is contributed by buffalo in 84 districts followed by cattle (55 districts). Thus, this detailed GIS-based representation of the spatial distribution of CH4 emission from livestock reveals that the highest emitting

districts (emission >50% of total CH4 emission) are located in the states of Uttar Pradesh, Gujarat, West Bengal, Rajasthan, Andhra Pradesh, and Maharashtra.

Methane Emission Assessment from Indian Livestock and Its Role in Climate Change Using…

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cattle, (b) emission from buffalo, (c) emission from sheep, and (d) emission from goat.

) from different categories of livestock at district levels in India, (a) emission from

The above estimation of livestock CH4 emission is estimated further used to estimate its role in climate change using climate metrics in terms of GTP and AGTP. These are further elaborated to estimate surface temperature response (ΔT) from CH4 emission due to Indian livestock. The results obtained from using Eqs. (2)–(4) (see Table 2) indicate significant contribution to GHG effect in global warming.

The estimated CH4 emission data is used to calculate GTP at 20 and 100 year time horizon as GTP20 and GTP100. GTP due to livestock CH4 emission at 20 year time horizon is 1030 Tg CO2e (GTP20) while for 100 year time horizon 62 Tg CO2e

3.2 Climate metric assessment

Figure 3.

159

CH4 emission (Gg year<sup>1</sup>

3.2.1 GTP of CH4 emission

Methane Emission Assessment from Indian Livestock and Its Role in Climate Change Using… DOI: http://dx.doi.org/10.5772/intechopen.81713

#### Figure 3.

CH4 emission (Gg year<sup>1</sup> ) from different categories of livestock at district levels in India, (a) emission from cattle, (b) emission from buffalo, (c) emission from sheep, and (d) emission from goat.

districts (emission >50% of total CH4 emission) are located in the states of Uttar Pradesh, Gujarat, West Bengal, Rajasthan, Andhra Pradesh, and Maharashtra.

#### 3.2 Climate metric assessment

The above estimation of livestock CH4 emission is estimated further used to estimate its role in climate change using climate metrics in terms of GTP and AGTP. These are further elaborated to estimate surface temperature response (ΔT) from CH4 emission due to Indian livestock. The results obtained from using Eqs. (2)–(4) (see Table 2) indicate significant contribution to GHG effect in global warming.

#### 3.2.1 GTP of CH4 emission

The estimated CH4 emission data is used to calculate GTP at 20 and 100 year time horizon as GTP20 and GTP100. GTP due to livestock CH4 emission at 20 year time horizon is 1030 Tg CO2e (GTP20) while for 100 year time horizon 62 Tg CO2e

As there are significant variations in terms of livestock populations up to district

Climate Change and Agriculture

level, CH4 emission pattern also shows wide variations in India as shown in Figure 3. Banas Kantha, Gujarat (112 Gg CH4); Paschim Medinipur, West Bengal (103 Gg CH4); and Jaipur, Rajasthan (102 Gg CH4) are top three districts in terms of livestock-related CH4 emission. Furthermore, out of the total 15.3 Tg CH4 emission in India, about 50% of the emission is contributed by 153 districts alone out of total 649 total districts. Within 153 districts, of the 4 livestock groups, maximum CH4 emission (more than 50%) is contributed by buffalo in 84 districts followed by cattle (55 districts). Thus, this detailed GIS-based representation of the spatial distribution of CH4 emission from livestock reveals that the highest emitting

State-wise livestock category-wise CH4 emission, Gg year<sup>1</sup> in the year 2012.

Table 4.

158

(GTP100). Among the livestock categories, cattle and buffalo are the major sources of CH4 emission and hence for GTP. The GTP of cattle and buffalo together is worked out to more than 953.9 Tg CO2e (GTP20) and 56.9 Tg CO2e (GTP100), respectively, as given in Figure 4. The results also indicate that enteric fermentation is the major contributor (more than 90%) to GTP.

Similarly, at state level, GTP20 and GTP100 vary between 0.01–184 Tg CO2e (GTP20) and 0.007–18.0 Tg CO2e (GTP100), respectively, with the lowest in Mizoram and highest in Uttar Pradesh (Table 5 and Figure 5b and d). At district level, GTP20 and GTP100 vary between 0.009–7.5 Tg CO2e (GTP20) and 3.75 � <sup>10</sup>�<sup>6</sup> –0.3 Tg CO2e (GTP100) (Figure 5a and c).

The GTP is a common unit of climate impact assessment per unit of GHG emissions. The results and findings of the climate metrics allow policymakers to develop GHG emission mitigation policies for different anthropogenic GHG emission sectors and for other non-CO2 GHG gases [23]. The different time horizon for GTP measurement (e.g., 20 and 100 years) allows comparisons of the global warming impacts of a gas over a period of time [24, 25]. The larger the value of GTP, the higher will be the potential for temperature change by a given non-CO2 GHG gas [15, 16, 26]. In the study, it is observed that climate change impact of CH4 in GTP100 timeframe is smaller as compared to GTP20, indicating that as the time horizon becomes longer, short-lived non-CO2 GHG gases have less impact on GTP [10, 12]. This also suggests immediate requirements of mitigation measures for CH4.

### 3.2.2 AGTP and surface temperature response (ΔT)

Similarly, climatic metric AGTP is also estimated, and it is worked out 4.56 � <sup>10</sup>�<sup>14</sup> and 2.28 � <sup>10</sup>�<sup>15</sup> K kg�<sup>1</sup> , for 20 and 100 year time frames, respectively. The AGTP can be used to explore more about climate change impact assessment than GWP [27]. The AGTP value is further used to estimate surface temperature response (ΔT). The surface temperature response (ΔT) of CH4 emission from the country for 20 year time frame is 0.70 mK (milli-Kelvin), and 100 year time frame is 0.036 mK.

At the state level, the highest global surface temperature response is observed resulting from CH4 emission in Uttar Pradesh, with the lowest response resulting from CH4 emission in Mizoram. CH4 emission from livestock from different states can contribute to the surface temperature response (ΔT20), ranging between 8.5 � <sup>10</sup>�<sup>5</sup> and 1.25 � <sup>10</sup>�<sup>1</sup> mK in 20 year time horizon. While in 100 year time horizon, <sup>Δ</sup>T100 varies from 4.23 � <sup>10</sup>�<sup>5</sup> to 6.50 � <sup>10</sup>�<sup>3</sup> mK for different states.

Potential rise in surface temperature due to Indian livestock sector that results from the annual CH4 emission at district level is also evaluated here. At 20 year time

horizon, the <sup>Δ</sup>T20 varies from 1.53 � <sup>10</sup>�<sup>7</sup> to 0.005 mK due to Indian livestock sector. However, at 100 year time horizon, the <sup>Δ</sup>T100 varies from 7.66 � <sup>10</sup>�<sup>9</sup> to

In addition to the above, the AGTP is also used to estimate the year-by-year response from a single year's CH4 emission from livestock. The continuous analysis of AGTP is used to calculate the climate change impact on surface temperature using the annual AGTP calculation. The surface temperature change by the year

State GTP20 GTP100 Andhra Pradesh 80.03 4.78 Arunachal Pradesh 1.29 0.08 Assam 31.09 1.86 Bihar 68.31 4.08 Chhattisgarh 31.65 1.89 Goa 0.17 0.01 Gujarat 71.30 4.26 Haryana 29.54 1.76 Himachal Pradesh 9.71 0.58 Jammu and Kashmir 12.86 0.77 Jharkhand 29.15 1.74 Karnataka 46.18 2.76 Kerala 4.87 0.29 Madhya Pradesh 87.75 5.24 Maharashtra 66.75 3.98 Manipur 0.98 0.06 Meghalaya 2.64 0.16 Mizoram 0.12 0.01 Nagaland 0.64 0.04 Odisha 34.75 2.07 Punjab 28.09 1.68 Rajasthan 101.29 6.05 Sikkim 0.44 0.03 Tamil Nadu 33.83 2.02 Tripura 2.72 0.16 Uttar Pradesh 183.79 10.97 Uttarakhand 10.12 0.60 West Bengal 51.12 3.05 UTs 1.54 0.09

Methane Emission Assessment from Indian Livestock and Its Role in Climate Change Using…

DOI: http://dx.doi.org/10.5772/intechopen.81713

It is estimated that the surface temperature will keep rising till 2021 reaching the peak temperature rise (ΔT) 0.937 mK and would start decreasing thereafter. After few years of span beyond the year 2084, the surface temperature response would

0.0002 mK.

161

Table 5.

(ΔT) is shown in Figure 6.

State-wise GTP20 and GTP100 of CH4 emission.


Methane Emission Assessment from Indian Livestock and Its Role in Climate Change Using… DOI: http://dx.doi.org/10.5772/intechopen.81713

Table 5.

(GTP100). Among the livestock categories, cattle and buffalo are the major sources of CH4 emission and hence for GTP. The GTP of cattle and buffalo together is worked out to more than 953.9 Tg CO2e (GTP20) and 56.9 Tg CO2e (GTP100), respectively, as given in Figure 4. The results also indicate that enteric fermentation

Similarly, at state level, GTP20 and GTP100 vary between 0.01–184 Tg CO2e (GTP20) and 0.007–18.0 Tg CO2e (GTP100), respectively, with the lowest in Mizoram and highest in Uttar Pradesh (Table 5 and Figure 5b and d). At district

The GTP is a common unit of climate impact assessment per unit of GHG emissions. The results and findings of the climate metrics allow policymakers to develop GHG emission mitigation policies for different anthropogenic GHG emission sectors and for other non-CO2 GHG gases [23]. The different time horizon for GTP measurement (e.g., 20 and 100 years) allows comparisons of the global warming impacts of a gas over a period of time [24, 25]. The larger the value of GTP, the higher will be the potential for temperature change by a given non-CO2 GHG gas [15, 16, 26]. In the study, it is observed that climate change impact of CH4 in GTP100 timeframe is smaller as compared to GTP20, indicating that as the time horizon becomes longer, short-lived non-CO2 GHG gases have less impact on GTP [10, 12]. This also suggests

level, GTP20 and GTP100 vary between 0.009–7.5 Tg CO2e (GTP20) and

Similarly, climatic metric AGTP is also estimated, and it is worked out

ment than GWP [27]. The AGTP value is further used to estimate surface

tively. The AGTP can be used to explore more about climate change impact assess-

temperature response (ΔT). The surface temperature response (ΔT) of CH4 emission from the country for 20 year time frame is 0.70 mK (milli-Kelvin), and

At the state level, the highest global surface temperature response is observed resulting from CH4 emission in Uttar Pradesh, with the lowest response resulting from CH4 emission in Mizoram. CH4 emission from livestock from different states can contribute to the surface temperature response (ΔT20), ranging between 8.5 � <sup>10</sup>�<sup>5</sup> and 1.25 � <sup>10</sup>�<sup>1</sup> mK in 20 year time horizon. While in 100 year time horizon, <sup>Δ</sup>T100 varies from 4.23 � <sup>10</sup>�<sup>5</sup> to 6.50 � <sup>10</sup>�<sup>3</sup> mK for different states. Potential rise in surface temperature due to Indian livestock sector that results from the annual CH4 emission at district level is also evaluated here. At 20 year time

Livestock category-wise GTP estimate for CH4 emission at different time horizons (a) GTP20 and (b) GTP100.

, for 20 and 100 year time frames, respec-

–0.3 Tg CO2e (GTP100) (Figure 5a and c).

immediate requirements of mitigation measures for CH4.

3.2.2 AGTP and surface temperature response (ΔT)

4.56 � <sup>10</sup>�<sup>14</sup> and 2.28 � <sup>10</sup>�<sup>15</sup> K kg�<sup>1</sup>

100 year time frame is 0.036 mK.

Figure 4.

160

is the major contributor (more than 90%) to GTP.

3.75 � <sup>10</sup>�<sup>6</sup>

Climate Change and Agriculture

State-wise GTP20 and GTP100 of CH4 emission.

horizon, the <sup>Δ</sup>T20 varies from 1.53 � <sup>10</sup>�<sup>7</sup> to 0.005 mK due to Indian livestock sector. However, at 100 year time horizon, the <sup>Δ</sup>T100 varies from 7.66 � <sup>10</sup>�<sup>9</sup> to 0.0002 mK.

In addition to the above, the AGTP is also used to estimate the year-by-year response from a single year's CH4 emission from livestock. The continuous analysis of AGTP is used to calculate the climate change impact on surface temperature using the annual AGTP calculation. The surface temperature change by the year (ΔT) is shown in Figure 6.

It is estimated that the surface temperature will keep rising till 2021 reaching the peak temperature rise (ΔT) 0.937 mK and would start decreasing thereafter. After few years of span beyond the year 2084, the surface temperature response would

3.2.3 Comparison between GTP and GWP

DOI: http://dx.doi.org/10.5772/intechopen.81713

Figure 6.

Table 6.

163

Here, CH4 emission values are used to compare its GTP results with GWP values using GWP of CH4, i.e., 34 [11]. The different values of GTP and GWP are given in Table 6. It is found that the results from GTP20 (1030 Tg CO2e) to GTP100 (62 Tg CO2e) drop off quickly compared to GWP20 (1292 Tg CO2e) and GWP100 (430 Tg CO2e). Both the climate metrics, GWP and GTP, are worked out in "CO2 equivalents" but fundamentally different by construction, and therefore different numerical values can be expected [11]. If we look at the findings of GWP and GTP over the same period of time, GWP100 is higher than that of GTP100 due to the integrative nature of the GWP [11]. Also in the case of GTP20 and GTP100, the GTP20 is 17 times

.

higher than that of GTP100, while GWP20 is only 3 times higher than that of

Category Enteric fermentation Manure management

Cattle 485.55 28.99 608.75 202.92 39.21 2.34 49.16 16.39 Buffalo 400.23 23.89 501.78 167.26 28.97 1.73 36.32 12.11 Goat 45.32 2.71 56.82 18.94 1.97 0.12 2.47 0.82 Sheep 20.30 1.21 25.45 8.48 8.69 0.52 10.90 3.63 Total 951.40 56.80 1192.80 397.60 78.84 4.71 98.85 32.95

Comparison between GTP20, GTP100, GWP20, and GWP100 of estimated CH4 emission from livestock.

GTP20 GTP100 GWP20 GWP100 GTP20 GTP100 GWP20 GWP100

Year-by-year surface temperature response (ΔT) due to constant rate of CH4 emission,Tg year<sup>1</sup>

Methane Emission Assessment from Indian Livestock and Its Role in Climate Change Using…

GWP100. The GTP calculation is based on assumptions about the climate sensitivity and heat uptake by the ocean and significantly varies with the change in these assumptions [11]. GTP is a metric which is used with reference to CO2, and it is equal to the ratio of AGTP of reference gas and AGTP of CO2. AGTP is the absolute GTP that gives temperature change per unit of GHG emission. As already discussed, GTP is an endpoint metric therefore for short GHG having half-life less than CO2; its climate metric, taken for large time horizon, is less than that of climate metric calculated for short time horizon [11]. The differences in GTP and GWP could be due to the fact that the GTP accounts the atmospheric adjustment time scale of the

#### Figure 5.

GTP estimate of CH4 emission in India: GTP20 of CH4 in Tg CO2e at (a) district and (b) state level; GTP100 of CH4 in Tg CO2e at (c) district and (d) state level.

asymptotically attain steady state. The continuous AGTP calculation is useful for policy makers when comparing multiple greenhouse gases. Due to high radiative forcing, CH4 can cause large impacts on climate change on short time scales, but due to its short lifetime, that impact decreases more quickly than for longer-lived GHG gases. Although the potential rise in surface temperature due to different livestock size in states and districts is global in nature, their contribution from livestock is significantly variable with respect to different livestock sizes. Hence, estimating contribution from each state and each district will be useful for policy makers to develop decentralized mitigation policy. Thus, the surface temperature response gives significant information that CH4 emission from livestock sector, even at small scale, can lead to significant climate change impact.

Methane Emission Assessment from Indian Livestock and Its Role in Climate Change Using… DOI: http://dx.doi.org/10.5772/intechopen.81713

Figure 6.

Year-by-year surface temperature response (ΔT) due to constant rate of CH4 emission,Tg year<sup>1</sup> .

#### 3.2.3 Comparison between GTP and GWP

Here, CH4 emission values are used to compare its GTP results with GWP values using GWP of CH4, i.e., 34 [11]. The different values of GTP and GWP are given in Table 6. It is found that the results from GTP20 (1030 Tg CO2e) to GTP100 (62 Tg CO2e) drop off quickly compared to GWP20 (1292 Tg CO2e) and GWP100 (430 Tg CO2e). Both the climate metrics, GWP and GTP, are worked out in "CO2 equivalents" but fundamentally different by construction, and therefore different numerical values can be expected [11]. If we look at the findings of GWP and GTP over the same period of time, GWP100 is higher than that of GTP100 due to the integrative nature of the GWP [11]. Also in the case of GTP20 and GTP100, the GTP20 is 17 times higher than that of GTP100, while GWP20 is only 3 times higher than that of GWP100. The GTP calculation is based on assumptions about the climate sensitivity and heat uptake by the ocean and significantly varies with the change in these assumptions [11]. GTP is a metric which is used with reference to CO2, and it is equal to the ratio of AGTP of reference gas and AGTP of CO2. AGTP is the absolute GTP that gives temperature change per unit of GHG emission. As already discussed, GTP is an endpoint metric therefore for short GHG having half-life less than CO2; its climate metric, taken for large time horizon, is less than that of climate metric calculated for short time horizon [11]. The differences in GTP and GWP could be due to the fact that the GTP accounts the atmospheric adjustment time scale of the


#### Table 6.

asymptotically attain steady state. The continuous AGTP calculation is useful for policy makers when comparing multiple greenhouse gases. Due to high radiative forcing, CH4 can cause large impacts on climate change on short time scales, but due to its short lifetime, that impact decreases more quickly than for longer-lived GHG gases. Although the potential rise in surface temperature due to different livestock size in states and districts is global in nature, their contribution from livestock is significantly variable with respect to different livestock sizes. Hence, estimating contribution from each state and each district will be useful for policy makers to develop decentralized mitigation policy. Thus, the surface temperature response gives significant information that CH4 emission from livestock sector,

GTP estimate of CH4 emission in India: GTP20 of CH4 in Tg CO2e at (a) district and (b) state level; GTP100 of

even at small scale, can lead to significant climate change impact.

Figure 5.

162

CH4 in Tg CO2e at (c) district and (d) state level.

Climate Change and Agriculture

Comparison between GTP20, GTP100, GWP20, and GWP100 of estimated CH4 emission from livestock.

component and the response time scale of the climate system, which is not considered in the GWP. Climatic impact assessment has been facing difficulties when comparing the effect of short- and long-lived GHGs. The GWP and GTP of longlived gases are the same [10]. However, for short-lived GHGs, the GWP does not account the radiative forcing for a short period.

factors. Therefore, it is feasible for all countries. But, country-specific or even smaller region-specific emission factors would bring more precise information. However, such issues could not be considered in the present work and would

Methane Emission Assessment from Indian Livestock and Its Role in Climate Change Using…

The findings of the study are CH4 emission, high GTP and surface temperature

comparing multiple gases with reference to CO2, whereas AGTP is the absolute GTP giving temperature change per unit of GHG emission. Temperature indices like GTP and AGTP both give the surface temperature change and response using pulse emission. GTP of any greenhouse gas is equal to the ratio of AGTP of the given gas and AGTP of CO2. The AGTP measures the temperature change over the period of time after the GHG emission. It depends upon some factors such as climate sensitivity and ocean uptake of heat by the ocean. All of these factors response vary with the time horizon and may substantially modify climate metrics GTP and AGTP. So, it follows a decreasing trend with an increase over the period of time from 20 to 100 years. GTP and AGTP follow the same pattern and also decrease with the year. These temperature indices GTP and AGTP both can be used to study the impact on surface temperature due to GHG emission with time. This finding helps to study the climate change impact on surface temperature from CH4 emission, which can cause climate damage over a short period of time, even emitted in small

Shilpi Kumari is thankful to the University Grant Commission, Government of India for UGC-SRF, for providing research fellowship (JRF) (Sr. No. 2121120406

. GTP is a metric, which is used in

response at district level, state level, and national level in India. The total CH4 emission in India is 15.3 Tg in 2012, with the highest almost 92% of the emission occurring via enteric fermentation. The GTP due to CH4 emission at 20 and 100 year time horizon in India is 1030 Tg GTP20 CO2e and 62 Tg GTP100 CO2e, respectively. The livestock emission in India has the potential to cause the surface temperature rise up to 0.69 mK and 0.036 mK over 20 and 100 year time period, respectively. At a state level, the emission can cause the surface temperature response (ΔT) to vary from 8.49 � <sup>10</sup>�<sup>5</sup> to 1.25 � <sup>10</sup>�<sup>1</sup> mK in 20 year time horizon and from 4.23 � <sup>10</sup>�<sup>5</sup> to 6.25 � <sup>10</sup>�<sup>2</sup> mK in 100 year time horizon. On the other hand, at district level, the <sup>Δ</sup><sup>T</sup> varies from 1.53 � <sup>10</sup>�<sup>7</sup> to 0.005 mK in 20 years and from 7.66 � <sup>10</sup>�<sup>9</sup> to 0.0002 mK in 100 years' time frame. The GTP values of CH4 for 20 and 100 years are 67 and 4, respectively. The AGTP values for the same time

require further investigation.

DOI: http://dx.doi.org/10.5772/intechopen.81713

horizons are 4.6 � <sup>10</sup>�<sup>14</sup> and 2.3 � <sup>10</sup>�<sup>15</sup> K kg�<sup>1</sup>

4. Conclusions

quantity.

165

Acknowledgements

and Ref. No: 18-12/2011(ii) EU-V).

Therefore, the GTP has been proposed for the comparison of the impact of GHG emissions on temperature changes at a specific time in future rather than the radiative forcing over a period of time [23]. Hence, we can say that the GTP compares temperatures at the end of a given time period due to GHG emissions. In comparison to GWP, GTP extends the information from radiative forcing to rise in the surface temperature relative to that of CO2 [11]. The GTP further extends the cause-effect chain by adding the temperature impact assessment in comparison with GWP and hence more relevant by comparing temperature changes [28]. The GTP is a function of time and used for analyzing the economic benefits from emission reduction. Therefore, it is useful to develop cost-effective policy for mitigation policies targeting temperature reduction.

Overall the results estimated here are compiled in Table 7 in which the minimum, the maximum, and average are given.
