Denmark's National Inventory Report 2005 - Submitted under the ...

In general country-specific TOW values are comparable to the TOW data calculated by the default
method when adjusted for industrial contribution, the uncertainty levels taken into account.
2. Comparison of country-specific Gross emission of methane with the Check method and the default IPCC
method (cf. Annex 3.E)
The IPCC GPG provides a check method for calculating the CH 4 emission from domestic wastewater.
The check method is based on default values (GPG, Box 5.1), where the only input parameter
is the population of the country. The result of the check method is used as reference for the two
other methods for the purpose of quality assurance and validity assistance. Results are given in
Table 8.20.
Table 8.20 Annual CH 4 emissions based on the check method and the country specific method for CH 4 gross
emissions.
Year 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Population (1000) 5140 5153 5170 5188 5208 5228 5248 5268 5287 5305 5322 5338 5351 5383
CH emissions (Gg)
4
Check method
27.0 27.1 27.2 27.3 27.4 27.5 27.6 27.7 27.8 27.9 28.0 28.1 28.1 28.3
CH emissions (Gg)
4
Country-specific 18.0 18.3 18.7 19.0 19.3 19.6 20.0 20.3 20.6 20.9 21.2 21.6 21.9 22.9
According to Table 8.20 the gross emission is ranging from approximately 27 to 28 Gg per year.
The default fraction of organic matter that degrades anaerobic is too high, i.e. 0.8, whereas 0.2-0.4
is more realistic according to national data (cf. Table 8.16). On the other hand, the check method
does not account for industry influent load that reached 42 % in 2003. The two above aspects influence
the size of the emission in opposite directions, which results in the highest similarity to the
late year country-specific emission level (cf. Annex 3).
Overall the check method is a good way of verifying the correctness of the units, activity data and
EF used in the country-specific calculations.
Nitrous oxide emissions
As there are no check method given in the IPCC and the emission estimated is based on standard
data on population, protein intake and default or constant emission factors not influenced by
changed in the characteristics of the activity data, these calculations are more or less straightforward.
The methodology for calculating the direct emission should be further evaluated when more data
becomes available.
For details regarding source-specific QA/QC and verification see Annex 3.E.
8.3.6 Recalculations
The emissions from wastewater handling were previously reported as zero. The methodology
used for the CRF Source Category 6B for CH and N O emissions is included for the first time in
4 2
this submission.
8.3.7 Planned improvements
Improvements in the calculation of the maximum methane producing potential with focus on disaggregation
into sewage and sludge treatment processes will be investigated. Improvements in
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