The Key Category Analysis
Mausami Desai
Climate Change Division
U.S. Environmental Protection Agency
UNDP-EPA Webinar
Key Elements of a National GHG Inventory System
April 10, 2013
Why Do a Key Category Analysis?
Conduct Key Category Analysis
IPCC Good Practice (Chapter 7); IPCC 2006 GL (Vol. 1, Ch. 4)
Identifies key categories and informs priorities for
National GHG Inventory preparation and improvement
•
Focus resources on Key Categories
•
Inform methodological choice, e.g. choose more advanced methods (Tier 2, 3)
 Obtaining better activity data, developing country-specific EF
Focus QA/QC, strengthen institutional arrangements, etc.
•
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Approaches for Conducting a Key Category Analysis
National Emissions
Key Categories
IPCC defines a key category as:
“a category that is prioritized within the
national inventory system because its
estimate has a significant influence on a
country’s total inventory of greenhouse
gases in terms of the absolute level, the
trend, or the uncertainty in emissions and
removals. Whenever the term key
category is used, it includes both source
(“emission”) and sink (“removal”)
categories.”
 Quantitative Approaches
 Qualitative Criteria
Identifying Appropriate Approach for Key Category Analysis
Quantitative Approaches for Conducting a Key Category Analysis
I. Level Assessment
 Identify categories that contribute at least 95% of
national emissions in the current GHG inventory
Energy
Industries
Non-Key
Categories
N2O from
Agricultural
Soils
Road
Transport
Cement
Production
CH4 from
Rice
Cultivation
CH4 from
Enteric
Fermentati
on
 Tier 1–sources/sinks are sorted and ranked according
to their contribution to total emissions
 Tier 2 – same as Tier 1 but accounts for uncertainty
Quantitative Approaches for Conducting a Key Category Analysis
Understanding the Mechanics of the
Key Category Analysis
Step 1) List all Inventory categories
Emission Category-CO2
Emission Category-CO2
Emission Category-CH4
Removal Category-CO2
Emission Category-N2O
….Emission Category…
X Tonnes
Y Tonnes
Z Tonnes
A Tonnes
B Tonnes
Quantitative Approaches for Conducting a Key Category Analysis
Step 2) Sort in descending order by
contribution to total (absolute)
Emission Category-CO2
Emission Category-N2O
Emission Category-CH4
Emission Category-CO2
Removal Category-CO2
….Emission Category…
Y Tonnes
B Tonnes
Z Tonnes
X Tonnes
A Tonnes
40%
25%
15%
15%
4%
Quantitative Approaches for Conducting a Key Category Analysis
Step 3) Sum cumulative contribution of
sources/ sinks (absolute in descending
order) until you reach 95%
Emission Category-CO2 Y Tonnes
Emission Category-N2O B Tonnes
Emission Category-CH4 Z Tonnes
Emission Category-CO2 X Tonnes
Removal Category-CO2 A Tonnes
…Emission Category…
40%
25%
15%
15%
4%
Key
Categories
Sum
95%
Quantitative Approaches for Conducting a Key Category Analysis
II. Trend Assessment
 Identify categories that have trend that is significantly
different from the trend of the overall inventory,
these categories may not be large enough to be
identified by the level assessment.
 Tier 1– sources and sinks are sorted and ranked
according to contribution to the inventory trend
 Tier 2 – same as Tier 1, but accounts for uncertainty.
Qualitative Approach to Conducting Key Category Analysis
Qualitative Criteria include indentifying
categories where:
• Mitigation techniques and technologies
applied
• Expected emission growth
• Uncertainties not yet quantified, but
presumed high
• Not yet included in inventory (completeness)
• Other criteria
– UNFCCC CGE training materials
– UNDP Managing the GHG Inventory Process
Other General Consideration for Conducting Key Category Analysis
With appropriate disaggregation, the KCA can highlight
important source and sink subcategories:
• Use subcategory disaggregation suggested by IPCC
– IPCC Good Practice Guidance, Ch. 7, Table 7.1
– IPCC 2006 Vol. 1, Ch. 4 Table 4.1
• Evaluate GHGs from a single category separately
– CO2 from Road Transportation
– CH4 from Road Transportation
– N2O from Road Transportation
• Important to include sub-categories for larger emissions sources:
– Ag/LULUCF
•
•
•
Land converted to Cropland
Land Converted to Grassland
Etc.
– Fossil Fuel Combustion (FFC) in the Energy Sector
• Splitting Stationary FFC into Energy vs. Manufacturing vs. Residential
• Disaggregate further by fuel types
• Splitting Transport into Road Transport vs. Aviation vs. Water-borne
Tools:Category
Key
Template Analysis
Workbook and ALU
National System Templates
Template 5 is the Key Category Analysis
Key Category Tool
Helps calculate Key Categories for you
using Microsoft Excel or OpenOffice Calc
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Where to Obtain the Key Category Analysis Tool
Download Link
http://www.epa.gov/climatechange/EPAactivities/internationalpartnerships/capacity-building.html
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Background on the Key Category Analysis Tool
• Consistent with 2006 GL
– Improves and corrects for errors in IPCC
Good Practice Guidance Ch. 7
• Capable of all Quantitative Approaches
– Tier 1 Level and Trend Analysis
– Tier 2 Level and Trend Analysis
• Generates summary table to insert in
KCA template
Preparing to Conduct Key Category Analysis
Recommended materials:
• Review this presentation
• Review IPCC GL as appropriate:
– IPCC Good Practice Guidance Ch. 7 – Methodological
Choice and Recalculation
– IPCC 2006, Vol. 1, Chapter 4 – Methodological Choice
and Identification of Key Categories
• Review EPA documentation template
• Collate Inventory summary table consistent with
categorization recommended by the IPCC GL
Preparing to Conduct Key Category Analysis: Sample Inventory
Sector
Category
Energy
1A1
Energy Industries
1A1
Energy Industries
1A1
Energy Industries
1A2
Manufacturing Industries and Construction
1A2
Manufacturing Industries and Construction
1A2
Manufacturing Industries and Construction
1A3b Road transportation
1A3b Road transportation
1A3b Road transportation
1
Residential
1
Residential
1
Residential
Industrial Processes and Product Use
2A1
Cement Production
2B5
Carbide Production
2C1
Iron and Steel Production
2C4
Magnesium Production
2
Aluminum
2
Aluminum
2
Aluminum
Agriculture, Forestry and Other Land Use
3A1
Enteric Fermentation
3A2
Manure Management
3A2
Manure Management
3B1a Forest Land Remaining Forest Land (Emissions)
3B1a Forest Land Remaining Forest Land (Removals)
3B3b Forest Land Converted to Grassland (Emissions)
Waste
4A
Solid Waste Disposal
4b
Biological Treatment of Solid Waste
4D
Wastewater Treatment and Discharge: Domestic
CO2
N2O
CH4
CO2
N2O
CH4
CO2
N2O
CH4
CO2
N2O
CH4
Gg
11,458
0
0
6,537
1
1
13,257
0
1
2,999
0
70
Current
year
(2000)
Gg
16,000
0
0
8,200
1
11
15,057
0
2
3,344
0
73
CO2
CH4
CO2
CO2
CO2
CF4
C2F6
4,500
1
4,973
1,355
924
-
CH4
CH4
N2O
CO2
CO2
CO2
Gas
CH4
N2O
CH4
%
10%
10%
10%
10%
10%
10%
15%
15%
15%
3%
3%
3%
Emission
factor
uncertainty
%
5%
5%
5%
5%
5%
5%
10%
10%
10%
5%
5%
5%
4,699
1
4,831
1,500
1,025
1
0
15%
15%
10%
7%
12%
12%
12%
15%
15%
5%
5%
10%
10%
10%
371
155
6
57,549
-85,361
37,373
368
164
11
65,450
-69,323
40,655
50%
50%
50%
20%
20%
20%
50%
120%
120%
25%
25%
25%
155
4
65
232
4
40
15%
10%
27%
15%
10%
35%
Base year
(1990)
Activity Data
Uncertainty
Filling in the Key Categories Table
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Key Category Analysis
How this Tool and Template Will Help!
In this tool and template:
• Identify all key categories of GHG emissions
• Rank emissions sources
• Describe and document how you completed the
key category analysis (KCA)
Help the inventory team:
• Conduct a KCA
• Perform an optional uncertainty analysis
• Identify the most important GHG categories
• Communicate key categories to the UN
• Identify areas for improving estimates
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Thanks For Your Attention!
Mausami Desai
Desai.mausami@epa.gov
+202.343.9381
U.S. EPA Inventory Preparation Tools
www.epa.gov/climatechange/EPAactivities/internationalpartnerships/capacity-building.html
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