The methodology for calculating greenhouse gas emissions in the tool is based on GHG Protocol for Cities (GPC) - Global Protocol for Community-
Scale Greenhouse Gas Emission Inventories. It does not specify the calculation methodologies to be used to estimate a city's emissions. Rather, it provides a clear framework for cities to assess their contribution towards mitigating GHG by taking certain sector specific actions envisaged under CSC assessment Framework, consistent with IPCC Guidelines, that emphasises transparency and organisation of emissions data in a way that facilitates consistency and comparability across cities globally.
Emissions are obtained by multiplying activity data (AD) for a specific activity or fuel type with its associated Emission Factor (EF).
Emissions = Activity Data (AD)x Emission Factor (EF)
The GHGs accounted for are Carbon Dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O). Fuel calorific values and emission factors for the
calculations are obtained from INCCA (Indian Network on Climate Change Assessmment) Report, CEA (Central Electricity Authority) Report & IPCC (Intergovernmental Panel on Climate Change) 2006.
1) Energy & Green Buildings
The methodology used for estimating emissions from fuel and electricity consumption under this sector is in tandem with the Stationary Sector methodology in the GPC. Emissions from this sector are estimated by multiplying fuel consumption (activity data) by the corresponding emission factors for each fuel, by gas. Activities identified under this sector include:
- Electricity consumption in the city
- Electricity consumption for Municipal Services
- Fuel combustion consumption for Municipal Services.
Fuels covered in the framework include:
• Diesel
• Petrol
• LPG
• CNG
- Electricity consumption for energy-efficient & non-efficient Street Lighting
- Electricity consumption for Green & non-Green Buildings
The equation below is an example of how emissions are being estimated
Emissions (in tonnes) = Diesel consumption for municipal services in the city (AD) x Emission Factor (EF) for combustion of Diesel
2) Urban Planning, Green Cover & Biodiversity
The tool estimates the amount of carbon sequestered for Indicator 4 – Proportion of Green Cover. Carbon Sequestration can be defined as the capture and storage of carbon that would otherwise be emitted to or remain in the atmosphere. The tool uses emission/removal factors
estimated for various categories of green cover and forest in the Green India Mission report published by the Ministry of Environment and Forests (MoEFCC) in May, 2010. The emission/removal numbers are based on the following categories of forests and green cover:
- Moderately dense forests - Degraded forests
- Scrub/Grassland vegetation
- Mangrove Ecosystem
- Wetlands
- Urban & Peri-Urban areas (including institutional lands)
- Agro-forestry & social forestry
The Methodology described by the report states that , “the use of carbon stock changes to estimate CO2 emissions and removals is based on the fact that changes in ecosystem carbon stocks are predominantly through CO2 exchanges between the land surface and the atmosphere. The increase in total carbon stocks over time are equated with net removal of CO2 from the atmosphere and decrease in total carbon stocks (less transfer to other pools such as harvested wood products) are equated with net emissions of CO2.”
GHG inventories require information on extent (in case of LULUCF, area) of an emission / removal category termed as 'Activity data' and emission or removal of GHG per unit of area (for example removal of CO2 per ha of added forest area) termed as 'Emission factors'.
The equation below demonstrates how the tool estimates the amount of carbon sequestered:
Carbon Sequestration (tC) = Area (AD) x Carbon Sequestration value (EF)
Activity data (AD) – Area statistics (in hectares)
Emission factor (EF) – refer to the ‘Carbon Sequestration value (tC per ha per year) in the table below:
|
CARBON SEQUESTRATION POTENTIAL OF GREEN INDIA MISSION INTERVENTIONS |
|||||
|
Mission components |
Area |
Carbon Sequestration value (tC/ha/year) |
Carbon |
Carbon |
Remark |
|
Areas / sub-landscapes with moderately dense forests |
2 |
0.4 |
0.8 |
2.93 |
IPCC value |
|
Areas / sub-landscapes with degraded forests |
4 |
1.5 |
6 |
22.02 |
An average C seq. value of 1.5 tC/ha/year has been arrived from 0.4 t/C/ha/year and 2.75 t/C/ha/year (refer end note) |
|
Areas / sub-landscapes with scrub/grasslands |
2 |
0.7 |
1.4 |
5.1 |
IPCC value |
|
Mangrove Ecosystem |
0.1 |
2.56 |
0.25 |
0.91 |
As per productivity estimates |
|
Wetland conservation |
0.1 |
0.4 |
0.04 |
0.14 |
IPCC value |
|
Urban / Peri-urban / Institutional lands |
0.2 |
0.3 |
0.06 |
0.22 |
IPCC value |
|
Agroforestry & social forestry ( 0.80 m ha area under improved agro-forestry; |
1.50 |
0.3 ( improved |
2.41 |
8.14 |
IPCC value & as per productivity estimates |
3) Mobility & Air Quality
Taken from the GHG Protocol for Cities (GPC), the methodologies for estimating transport emissions can be broadly categorized as top-down and bottom-up approaches.
- Top-down approaches start with fuel consumption as a proxy for travel behaviour. Here, emissions are the result of total fuel sold multiplied by a GHG emission factor for each fuel.
- Bottom-up approaches begin with detailed activity data. Bottom-up approaches generally rely on the ASIF (Activity, Share, Intensity, Fuel) framework for determining total emissions
The tool uses the ASIF (Activity, Share, Intensity, Fuel) framework to estimate emissions, which relates travel activity, the mode share, energy intensity of each mode, fuel, and vehicle type, and carbon content of each fuel to total emissions. The amount of Activity (A) is often measured as VKT (vehicle kilometres travelled), which reflects the number and length of trips. Mode share (S) describes the portion of trips taken by different modes (e.g., walking, biking, public transport, private car) and vehicle types (e.g., motorcycle, car, bus, truck). Energy Intensity (I) by mode, often simplified as energy consumed per vehicle kilometre, is a function of vehicle types, characteristics (e.g., the occupancy or load factor, represented as passengers per km or tonnes cargo per km) and driving conditions (e.g., often shown in drive cycles, a series of data points showing the vehicle speed over time). Carbon content of the fuel, or Fuel factor (F), is primarily based on the composition of the local fuel stock.
Emissions= Activity (A) * Mode Share (S) * Intensity (I) * Fuel (F)
In case data for Annual Vehicle Kilometres Travelled (VKTs) is not available, it can be estimated using one of the following ways:
i. Using Average Trip Length and Number of trips Annual VKTs = Avg. Trip Length x No. of trips x 365"
ii. Average route length, Number of vehicles & route frequency for eg. in case of buses, ferries and shared vehicles following the same daily route Annual VKTs = Avg. route length x No. of buses x route frequency x 365
iii. Average daily vehicle kilometres travelled (VKTs) and Number of vehicles Annual VKTs = Daily avg. VKTs (per day, per vehicle) x Number of vehicles x 365
iv. Total daily vehicle kilometres travelled (VKTs) by vehicular fleet Annual VKTs = Daily avg. VKTs (per day, vehicular fleet) x 365"
Below is an example of how the ASIF approach can be used to estimate emissions –
Emissions = Total VKTs of CNG bus fleet (AD) x [1/Mileage of CNG buses (default or specific)] (Intensity) x Emission factor for combustion of CNG (Fuel factor)
Since we are calculating emissions by specific shared vehicle type, mode share(S) will be 1.
4) Water Resource Management
The tool estimates emissions for Indicator 5 & 6 under the Water Resource Management sector that are about wastewater management & water supply management systems, respectively. The methodology used for calculating emissions from electricity consumption for water resource management is in tandem with the Stationary Sector methodology in the GPC.
Emissions from this sector are estimated by multiplying electricity consumption (activity data) by the India-specific emission factor for electricity. Activities identified under this sector include:
- Wastewater management - Water supply management
The equation below is an example of how emissions are being estimated –
Emissions (in tonnes) = Electricity consumption for wastewater management in the city (AD) x India-specific Emission Factor (EF) for electricity
The tool estimates electricity consumption for Indicator 2 – Extent of Non-Revenue Water, using the assumption that electricity required to supply 1000 litres of water by the municipal authorities is 2.13 kWh The above assumption has been derived from MoEF's (Ministry of Environment & Forests, India) report titled 'Low Carbon Lifestyles'.
The equation below is an example of how electricity consumptionis being estimated –
Annual electricity consumption for Non-Revenue Water (in kWh)= Total Non-Revenue Water (in MLD) x 2.13 x 0.001 x 365
5) Waste Management
Indicator 4 talks about GHG emissions from municipal waste processing and treatment facilities. There are three ways of managing municipal solid waste – waste treated through biological processes like composting, bio-methanisation etc, waste treated through incineration processes like waste to energy and waste disposed to landfills/dumpsites. The methodology to estimate emissions from the waste sector has been adopted from the GHG Protocol for Cities (GPC).
To estimate emissions from disposing solid waste to landfills/dumpsites, the tool uses the Methane Commitment (MC) model, which assigns landfill emissions based on waste disposed in a given year. It takes a lifecycle and mass-balance approach and estimates landfill emissions based on the amount of waste disposed in a given year, regardless of when the emissions occur (as a portion of emissions are released every year after the waste is disposed). Two main factors are essential in calculating emissions from disposal and treatment of solid waste – the mass of waste disposed and the amount of degradable organic carbon (DOC) within the waste, which determines the methane generation potential. Thus, in order to estimate emissions by quantifying waste mass and degradable organic content, the following steps need to be followed –
- Determine the quantity (mass) of waste generated by the city and how and where it is treated
- Determine the emission factor – for solid waste disposal the methane generation potential is the emission factor, which is a function of degradable organic content (DOC)
- Multiply quantity of waste disposed by relevant emission factors to determine total emissions "
Degradable Organic Content (DOC) represents a ratio or percentage that can be estimated from a weighted average of the carbon content of various components of the waste stream. The equation below estimates DOC using default carbon content values:
DOC = (0.15 X A) + (0.2 X B) + (0.4 X C) + (0.43 X D) + (0.24 X E) + (0.15 X F)
A = Fraction of solid waste that is food
B = Fraction of solid waste that is garden waste and other plant debris
C = Fraction of solid waste that is paper
D = Fraction of solid waste that is wood
E = Fraction of solid waste that is textiles
F = Fraction of solid waste that is industrial waste
Methane Generation Potential(LO) is an emission factor that specifies the amount of CH4 generated per tonne of solid waste. It can be estimated using the equation below –
LO = MCF X DOC X DOCF X F X (16⁄12
| Data Element |
Definations |
Units | Value |
| MCF | Methane Correction Factor (based on management type) – part of the landfilled materials that is left to degrade anaerobically. | Unitless |
Managed = 1.0
|
|
DOC |
Degradable organic carbon – the portion of the waste stream that can decompose under aerobic conditions |
Tonnes C/tonne waste |
Computed value |
|
DOCF |
The fraction of DOC ultimately degraded anaerobically |
Unitless |
Assumed to be 0.6 |
|
F |
The fraction of methane in landfill gas |
Unitless |
Default range 0.4-0.6 (Usually taken to be 0.5) |
|
16/12 |
Methane to carbon ratio |
Unitless |
16/12 |
Below is the equation to estimate emissions using the methane commitment model for solid waste sent to landfill:
CH4 emissions = MSWx X LO X [1 – frec] X (1 – OX)
| Data Elements | Definations | Units | Value |
| MSWx |
Mass of solid waste sent to landfill in inventory year |
Metric tonnes | User input |
|
LO |
Methane generation potential |
Tonnes C/tonne waste | Computed value |
|
frec |
Fraction of methane recovered at the landfill (flared or energy recovery) |
Unitless | User input |
|
OX |
Oxidation factor |
Unitless |
0 for unmanaged landfills |
Biological treatment of solid waste refers to composting and anaerobic digestion of organic waste, such as food waste, garden and park waste, sludge, and other organic waste sources. Biological treatment of solid waste reduces overall waste volume for final disposal (in landfill or incineration) and reduces the toxicity of the waste. In cases where waste is biologically treated (like composting), cities shall report CH4, N2O and non-biogenic CO2 emissions.
Below are equations to estimate direct emissions from biologically treated solid waste:
CH4 emissions = [∑i (mi X EF_CH4i X 10-3 – R]
N20 emissions = [∑i (mi X EF_N20i X 10-3]
| Data Elements | Definations | Units | Value |
| m |
Mass of organic waste treated by biological treatment type, i |
kg |
User input |
|
EF_CH4 |
CH4 emission factor based upon treatment type, i |
g CH4/kg waste |
Dry waste – 10 Wet waste – 4 |
|
EF_N2O |
N2O emission factor based upon treatment type, i |
g N2O/kg waste |
Dry waste – 0.6 |
|
i |
Treatment type: composting or anaerobic digestion |
NA |
Assumed to be composting |
|
R |
Total tonnes of CH4 recovered, if gas recovery system is in place |
Tonnes |
User input |
Incineration of waste is a controlled, industrial process, often with energy recovery where inputs and emissions can be measured, and data is often available.
Below is the equation to estimate non-biogenic CO2 emissions from the incineration of waste:
CO2 emissions = m X ∑i(WFi X dmi X CFi X FCFi X OFi) X (44/12)
| Data Elements | Definitions | Units | Value |
| m |
Mass of waste incinerated |
tonnes |
User input |
|
Wfi |
Fraction of waste consisting of type i matter |
Unitless |
Dry waste – 10 |
|
dmi |
Dry matter content in the type i matter |
% |
Default IPCC 2006 values |
|
CFi |
Fraction of carbon in the dry matter of type i matter |
% |
Default IPCC 2006 values |
|
FCFi |
Fraction of fossil carbon in the total carbon component of type i matter |
% |
Default IPCC 2006 values |
|
Ofi |
Oxidation fraction or factor |
% |
Default IPCC 2006 values |
|
i |
Matter type of the solid waste incinerated such as paper/cardboard, textile, food waste etc. |
NA |
NA |
Below is the default data for CO2 emission factors for incineration of Municipal Solid Waste (MSW):
|
DEFAULT DRY MATTER CONTENT, DOC CONTENT, TOTAL CARBON CONTENT AND FOSSIL CARBON FRACTION OF DIFFERENT MSW COMPONENTS |
|||||||||
|
MSW component |
Dry matter content in % of wet weight |
DOC content in % of wet waste |
DOC content in % of dry waste |
Total carbon content |
Fossil carbon fraction in % of total carbon |
||||
|
|
Default |
Default |
Range |
Default |
Range |
Default |
Range |
Default |
Range |
|
Paper/cardboard |
90 |
40 |
36 - 45 |
44 |
40 - 50 |
46 |
42 - 50 |
1 | 0 - 5 |
|
Textiles |
80 | 24 |
20 - 40 |
30 |
25 - 50 |
50 |
25 - 50 |
20 | 0 - 50 |
|
Food waste |
40 | 15 |
44044 |
38 |
20 - 50 |
38 |
20 - 50 |
- | - |
|
Wood |
85 | 43 |
39 - 46 |
50 |
46 - 54 |
50 |
46 - 54 |
- | - |
|
Garden and Park waste |
40 | 20 |
18 - 22 |
49 |
45 - 55 |
49 |
45 - 55 |
0 | 0 |
|
Nappies |
40 | 24 |
18 - 32 |
60 |
44 - 80 |
70 |
54 - 90 |
10 | 10 |
|
Rubber and Leather |
84 |
(39) 5 |
(39) 5 |
(47) 5 |
(47) 5 |
67 |
67 |
20 | 20 |
|
Plastics |
100 | - | - | - | - |
75 |
67 - 85 |
100 | 95 - 100 |
|
Metal |
100 | - | - | - | - |
NA |
NA | NA | NA |
| Glass | 100 | - | - | - | - |
NA |
NA | NA | NA |
|
Other, inert waste |
90 | - | - | - | - |
3 |
0-5 | 100 | 50 -100 |
Below is the equation to estimate CH4 emissions from the incineration of waste:
CH4 emissions = ∑ (IWi X EFi) X 10-6
| Data Elements | Definitions | Units | Value |
|
IWi |
Amount of solid waste of type i incinerated |
tonnes |
User input |
|
EFi |
Aggregate CH4 emission factor |
g CH4/ton waste |
Default IPCC 2006 values |
|
10-6 |
Converting factor from gCH4 to tCH4 |
Unitless |
NA |
|
i |
Category or type of waste incinerated, specified as follows: Municipal Solid Waste, Industrial Solid Waste, Hazardous Waste, Clinical Waste, Sewage Sludge, Others |
NA |
Assumed to be Municipal Solid Waste (MSW) only |
Below are the CH4 emission factors for incineration of MSW:
| Type of premises | Temporary | Permanent |
|---|---|---|
| Continuous incineration | Stoker | 0.2 |
| Fluidised bed | Almost 0 | |
| Semi-continuous incineration | Stoker | 6 |
| Fluidised bed | 188 | |
| Batch-type incineration | Stoker | 60 |
| Fluidised bed | 237 |
Below is the equation to estimate N2O emissions from the incineration of waste:
N2O emissions = ∑ (IWi X EFi) X 10-6
|
Data Elements |
Definations |
Units |
Value |
|
IWi |
Amount of solid waste of type I incinerated |
tonnes |
User input |
|
EFi |
Aggregate N2O emission factor |
g N2O/ton waste |
Default IPCC 2006 values |
|
10-6 |
Converting factor from gN2O to tN2O |
Unitless |
NA |
|
i |
Category or type of waste incinerated, specified as follows: Municipal Solid Waste, Industrial Solid Waste, Hazardous Waste, Clinical Waste, Sewage Sludge, Others |
NA |
Assumed to be Municipal Solid Waste (MSW) only |
Below are the default N2O emission factors for different types of waste and management practices:
|
Type of waste |
Technology / Management practice |
Emission factor |
Weight basis |
|
MSW |
Continuous & semi-continuous incineration |
50 |
Wet weight |
|
MSW |
Batch-type incineration |
60 |
Wet weight |
Overall the tool estimates emissions from the following categories as described in GHG Protocol for Cities -
• CH4 emissions from disposing solid waste to landfills/dumpsites – using the Methane Commitment Model
• Direct emissions from biologically treated solid waste; based on treatment type, amount of waste and CH4 and N20 emission factors
• Non-biogenic CO2 emissions from the incineration of waste based on carbon content in the specific types of waste and oxidation factors for solid waste.
• CH4 emissions from the incineration of waste based on the type of waste, amounts of solid waste and emissio
• N2O emissions from the incineration of waste based on the type and amount of solid waste and respective emissions factors