Results and Discussion

Quantifying Spatiotemporal Land-Use Changes

Temporal land-use analyses reveal the decline of forest cover in Karnataka from 1985 to 2019 (Fig. 3). Currently, 15% of the State’s geographical area is under forests compared with 21% in 1985. Large-scale developmental activities such as the construction of a series of reservoirs and dams, creation of special economic zones, townships, land conversion for built-up areas have led to the loss of large tracts of forests. The abrupt land-use conversion has resulted in a loss of productive agriculture lands near the cities such as Bengaluru, Mysore, Hubli-Dharwad, Shimoga, etc. The districts such as Kodagu, Uttara Kannada, Bengaluru, Shimoga, Belgaum, Dakshina Kannada, and Chikmagalur have been experiencing a large-scale land cover due to the unplanned developmental activities. Post-1990s, the state witnessed large-scale land-use transitions due to industrialization, urbanization, an increase of horticulture crops, conversion from agriculture to market-based crops (higher economic), etc.

Table 5 Vehicle details of Karnataka

Table 6 CO2, CH4, and N2O EF for different type of

The forest cover now is confined to major conservation reserves such as protected areas, national parks, wildlife sanctuaries. The built-up cover has increased from

0.47 to 3% from 1985 to 2019 causing an impact on agriculture, forest, and lakes (Fig. 4). This necessitates the sustainable land-use policies to arrest deforestation and abrupt land conversions.

4.2 Carbon Sequestration Potential of Forest Ecosystems in Karnataka

The field data supplemented with data from published literatures were used to compute per hectare biomass across various types of forests in Karnataka. The anal- yses of the above ground biomass show that the grids in the Western Ghats part of Karnataka have higher AGB > 1000 Gg (Giga gram). The grids of evergreen forested areas represent the greater values of biomass compared with the other forest types. The total AGB of forests is about 1013.7 Tg (Teragram) with stored carbon of 506.8 Tg (in 1985), which is now reduced to 678 Tg and 339 Tg, respectively (2019). The temporal decline of AGB values in the districts of Kodagu, Shimoga, Uttara Kannada, and Dakshina Kannada is due to anthropogenic pressure (Fig. 5). The Mysore Chamrajnagara and Bellary districts also reflect a decline in AGB values during 2005–2019. The districts of Uttara Kannada, Kodagu, Udupi, Chikkamagaluru with relatively higher forest cover have higher carbon sequestration compared to the other parts of the state. The temporal decline in carbon sequestration is due to the deforestation and land degradations due to the sustained anthropogenic pressures (Fig. 6). The annual increment in carbon from forests depicts the grids of Western Ghats has higher increment (>20 Gg) compared with other parts of the state due to less disturbances (Fig. 7). The temporal changes in incremental biomass and carbon highlight the decline of forest cover. The districts such as Shimoga, Mysore, Bellary have lower incremental biomass and carbon values due to deforestation with the rapid land-use changes (Fig. 8). Temporal BGB highlights the decline from 275 Tg (1989) to 180 Tg (2019). The grids consisting of evergreen forests (of Western Ghats) show higher values of >600 Gg SOC, while other regions are with relatively lower values (Fig. 9). The loss of forest cover has degraded the SOC potential and the region is exposed to the sunlight resulting in emissions. The incremental BGB is estimated to understand the increment during 1989–2019, which further confirm of variations (Fig. 10). The districts such as Uttara Kannada, Kodagu, Dakshina Kannada forests

have grids expressing moderate incremental BGB of greater than 6 Gg compared with other districts across the state.

In order to protect the land under greening initiatives and to sustain market demand for the timber, Karnataka forest department has implemented monoculture plan- tations in the state. The AGB, BGB, and their carbon values were accounted to understand the role of plantations in carbon sequestration apart from arresting land degradations. The total carbon has been estimated based on the AGB and BGB values as a sum of forest and forest plantations biomass. Figures 11 and 12 show the AGB

for forest and plantations accounted to 1056.90 Tg with carbon sequestration of

528.45 Tg (in 1985), which is now reduced to 732.83 Tg and 366.41Tg, respectively. Figure 13 shows BGB from forest plantation and agriculture areas across the state accounted to 275.43 (1985), which is now reduced to 180.54 Tg. The plantations though not shown any significant contribution of ecosystem services compared with

the forest, but supported in sequestration. The Uttara Kannada grids have significant AGB and BGB values.

Total AGB and BGB from forests are about 782.1 Tg (1985), which is reduced to 519.36 Tg (2019) due to LU conversions (Fig. 14). The total carbon sequestration from forest plantation and agriculture areas together is about 1289.1 Tg (1985) and

858.48 Tg (2019) due to changes in LU with the burgeoning anthropogenic pressures.

Figure 15 depicts the loss of carbon sequestration of 433.43 Tg during 1985–2019 in the forest, plantation, and agriculture sectors. The loss of 264 Tg carbon sequestration potential during 1985–2019 emphasizes the need for prudent management activities to curb the forest loss and improvement of carbon sequestration (Fig. 16). The grids covered in districts of Bellary, Mysore, Chamarajanagar, Uttara Kannada, Kodagu have witnessed higher transitions in carbon sequestration potential.

Quantification of Carbon Emissions in Karnataka

The carbon emissions from various sectors including livestock, agriculture, and industries for the year 2019 were accounted to be 150.65 Tg. The energy and trans- portation are a major source of emissions in Karnataka, highlight the necessity of mitigative interventions. Figure 17 highlights major contributions from industrial

activities (29%), energy generation (28%), transportation (25%), and paddy culti- vation (13%). Large-scale industries having the capacity of greater than 20,000 tons and covering various sectors of cement, petrochemical, steel, paper mills, etc., were considered and the total emission is about 42,995.93 Gg. The energy sector contributes to emissions of 42,731 Gg from thermal—and diesel-based power gener- ation. The residue available from the agriculture sector has been quantified, which shows the northern districts of the state have higher residues greater than 6000 tons per year, and the emissions respective residue burning account to greater than 1 Gg. Emissions due to the crop residue burning are about 2222.25 Gg (Fig. 18).

Considering the contribution of crop burning to atmospheric pollution as well as likely increase in GHG, there is a need to prohibit this practice of crop residue burning unless the burning is for the purpose of disease control or the elimination of plant pests, the disposal of straw stack remains or broken bales, for education or research. Retention of crop residues in the respective agricultural field after harvesting is an effective antierosion measure. The crop residue has alternative uses such as fodder, ethanol production, energy, paper and pulp industry, manure, etc. Barriers to commercial utilization of crop residues include dispersed generation, transportation cost, etc. However, with the incentive and support from the government would help in the conversion of agricultural residues to viable products while mitigating carbon emissions from burning. Figure 19 gives the distribution of livestock in Belgaum, Yadgir, Hassan, Mysore, Haveri, and Tumkur districts. The emission from livestock assessed for enteric fermentation and manure is about 2963 Gg. The farmers are growing paddy in all the districts and the larger area under paddy is in North Karnataka districts (Fig. 20). CH₄ emissions associated with paddy cultivation are about 19,215

Gg (CO₂ equivalent) and Bagalkot, Raichur, Bellary, Gadag, Gulbarga districts have higher contributions toward emission from the livestock sector.

The emission due to the fuelwood burning in the domestic sector of a rural household is about 1138 Gg and Fig. 21 illustrates that Belgaum, Udupi, Dakshina Kannada, Kodagu, and Dharwad districts are with the higher fuelwood consumption (Fig. 21). The waste generated in households of Karnataka state is about 2,91,451 tons per year, which contributes emissions of 3886.72 Gg. Figure 22 demonstrates that major cities (Bangalore, Mangalore, Mysore, Dharwad) and towns (Shimoga,

Bellary, Tumkur) of the state contribute significantly to the emission. due to indis- criminate disposal. Wastewater generated in urban areas is either partially treated or untreated and is discharged to the water bodies. Figure 23 presents the emission from wastewater indicating higher emissions from the major cities. Emissions from the transportation sector include CO₂, CO, NO_x, CH₄, SO₂, PM, HC, which accounts to 38,440.56 Gg. Figure 24 illustrates the spatial distribution of emission from the transport sector in Karnataka with the major contributions from Bangalore, Kolar, Chikballapur, Tumkur and Mysore districts due to higher number of vehicles.

Carbon Ratio (CR) or Carbon Status in Karnataka

The carbon status of a region or carbon ratio (CR) refers to the ratio of sequestered carbon in the ecosystems to emissions aggregated from all sectors or activities. CR values greater than 1 indicate carbon sequestration higher than emissions. Grid- wise carbon sequestration and emission were computed for 2019. Figure 25a and b give the grid-wise carbon sequestration and emissions during 2019. The annual sequestered carbon is about 16.1 Tg, while emission is 150.65 Tg, which highlights about 11% of the emission is sequestered by forest ecosystems in Karnataka. The districts or grids in the Western Ghats region have good sequestration potential with the least emissions compared with other regions. High carboemitting districts include Bangalore, Mysore, Dharwad, Bellary, and Raichur. CR ratio computed grid wise is

depicted in Fig. 26 highlights of CR > 1 for grids covered in the districts of Uttara Kannada, Kodagu, part of Dakshina Kannada, and Udupi. The other grids are with lower CR ( 0) indicating carbon-negative situation.

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The study emphasizes the need to evolve appropriate policies to decarbonize through prudent afforestation policies to mitigate emissions. Afforestation with native species will not only aid in the carbon sequestration but also enhances hydro- logical and food security services, evident from the existence of perennial streams in the catchments dominated by native species compared with the seasonal or intermit- tent streams in either degraded catchments or catchments dominated by monoculture plantations. Also, due to pollination services with the presence of diverse pollinators, the crop productivity in agriculture is higher compared with the degraded landscapes highlighting the linkages of water availability, food security, and carbon security with the land cover dynamics.

Strategies for Carbon Mitigation

The strategies for carbon mitigation covering local and global perspectives would aid in framing prudent policies toward the sustainability of natural resources. Realizing the increase in greenhouse gas emissions due to the accelerated deforestation process has necessitated the measures toward adaptation and mitigation strategies for global

warming and climate change. Conference of the Parties (refer to the countries) signed up to the 1992 United Nations Framework Convention on Climate Change. Kyoto Protocol was the first global initiative proposed at 3rd Conference of Parties (COP) of the United Nations Framework Convention on Climate Change (UNFCCC) in 1997 to curb deforestation and promote forest conservation (Humphreys, 2008). During the 21st COP at Paris 170 countries committed to reduce greenhouse gas emissions and limit the global temperature increase to below 2 degrees Celsius (3.6 F) above preindustrial levels by the year 2100. In this regard, India pledged that 40% of power capacity would be based on nonfossil fuel sources and of creating an additional “carbon sink” of 2.5–3 billion tonnes of carbon dioxide equivalent through additional forest and tree cover by 2030.

Reduced Emissions of Deforestation (RED) has emerged as an initiative for conservation in 2005 at 11th COP meeting to support developing countries. REDD materialized at the 18th COP proposed to offer incentives for the conservation and enhancement of the forest carbon stock and the sustainable management of forests in 2012. REDD has been playing a significant role in forest conservation while addressing challenges and supporting direct/indirect costs involved in forest manage- ment [14]. REDD , while providing economic benefits to the local communities, has improved natural resource management in developing countries and is a form of Payments for Ecosystem Services (PES). The conservation, sustainable manage- ment of forests, and enhancement of forest carbon stocks in developing countries have been achieved with the marketing of carbon credits under the voluntary carbon standard systems through a technical procedure [27]. Carbon trading is an effective

measure toward payment for ecological services, such as forest conservation, which has been established based on a rigorous valuation of these ecosystem services to encourage afforestation in a larger scale and support community livelihoods, which are at the greatest risk due to LULC change and its associated impacts. The annual sequestered carbon in forest ecosystems of Karnataka is about 16.1 Tg, which as per carbon trading accounts to be INR 34 billion ($0.5 billion) at carbon trading of INR 2142 ($30) per tonne, which highlights the scope for higher carbon credits with refor- estation of degraded landscapes. In this regard, the Government of India came up with CAMPA (Compensatory Afforestation Fund Management and Planning Authority) to compensate for the loss of forest area and to maintain sustainability. The act emphasized of ecological compensation based on net present value (NPV) for the loss of forest ecosystem, while implementing developmental projects.

Although policies to implement adaptation and mitigation measures may be estab- lished at a global, national, or regional level, the consequences of climate change and the necessary adaptation have to be undertaken locally. The management options to minimize the impact of climate change include: promotion of reduced use of fossil fuels and development of clean energy; efficient use of water resources; developing low-cost sustainable technologies; improving health care and pest control; devel- oping and using drought-resistant crops; constructing disaster-resistant buildings and infrastructure. Renewable energy sources include solar power, wind, waste to energy, are to be promoted through incentivized mechanism across all levels. The creation of people’s nurseries under benefit sharing in accordance with the various forest regulations and provisions and Forest Dweller’s Act, 2006, is recommended to get location-specific species saplings would enhance the rural employment oppor- tunities. The fencing of blocks of forest lands with basal areas of less than 15 sq. m each, for minimum periods of 8–10 years, will prevent the entry of domestic cattle and humans into these protected blocks and pave the way for natural regeneration of especially native species of plants. Carbon reduction is achieved by promoting alternative materials of least carbon footprint, efficient recycling technologies, and remanufacturing as well as recovering the virgin materials. Increased emphasis on research, education, training, and awareness needs to be provided to the employees to make aware all advanced/alternative energy technologies for reducing emission through nongovernmental organizations (NGOs) and public–private participation.