1. Harmonisation with IPCC
This will end in tiers...
U N I V E R S I T Y O F A A R H U S
Dept of Agroecology

2. Three-tiered approach
Replaces Simple/Detailed methodologies.
Tier 1.
Can only be used for non key sources.
Tier 2.
Minimum requirement for key sources.
Tier 3.
Any method more detailed than Tier 2.
EU want focus on Tier 1 and 2.
Existing Tier 3 methods will be retained.

3. Three-tiered approach
EU want focus on Tier 1 and 2.
Existing Tier 3 methods will be retained.
Relation between Simple/Detailed and Tier methodologies will vary between compounds.
Harmonisation with IPCC.

4. Tier 1 Very simple. Activity x Emission factor.
E.g. Number of cows x kg emission per cow.
Type of activity data prescribed.
Default emission factors prescribed.

5. Tier 2 Activity x Emission factor. More detailed than Tier 1.
For example:
Number of dairy cows x kg emission per dairy cow.
Number of suckler cows x kg emission per suckler cow.
Type of activity data prescribed.
Default emission factors prescribed.
Additional information may be required.

6. Example Tier 2 for NH3
IPCC Tier 2 requires estimation of feed characteristics and N excretion.
IPCC does not distinguish between emissions from animal housing and manure storage.
Not adequate for Guidebook.
Will require default emission factors for different housing types.

7. Example Tier 2 for NH3
IPCC Tier 2 has relatively detailed manure storage categories.
Will require default emission factors for different storage types.
IPCC does not identify emission occurring immediately after field application.
Will require default emission factors for different application methods.
Will need to distinguish between solid and liquid manures.

8. Definition of Tier 3 Tier 3 is more detailed than Tier 2.
More detailed does not necessarily mean more accurate.
Depends on quality of activity data and emission factors.
Need independent review of Tier 3 (a la IPCC), to ensure quality.