ghg-inventory-1990-2013

Total emissions and key activity data from the common reporting format (CRF) are
checked for accuracy against total emissions and activity in the workbooks. Subsector
totals are also checked.
Recalculations
Recalculations are agreed with the Ministry for the Environment and the Reporting
Governance Group every year before the Inventory compilation commences.
Recalculations are compared with previous submissions and, as far as possible,
explained and confirmed by the changes in method or activity data.
Anomalous results from recalculations are checked and, if necessary, corrected.
The Agriculture Inventory compiler completes recalculation forms, signs the forms
and forwards them to the Ministry for the Environment. 19
Periodic reviews
Periodic reviews are completed on different aspects of the Inventory.
In recent years, the livestock population models and productivity parameters have
been reviewed (eg, Thomson et al, 2010) and used to update and improve the Tier 2
model. During 2013 the nitrogen retention rates in liveweight gains, milk protein and
fibre, and pasture quality were reviewed, but the reviews were not completed in time
to be submitted to the 2013 Agriculture Inventory Advisory Panel meeting for
approval. The results are expected to be incorporated in the 2016 Inventory
submission.
During the 2012 submission, new crops were included for the first time and a new
complex methodology was implemented. For the 2013 submission, Plant and Food
Research, which has expertise in this area, was hired to review the workbooks, check
the formulae and model parameters.
During the 2015 submission, a mutual bilateral Greenhouse Gas Inventory review
was held between Australia and New Zealand, which included the Agriculture sector
(Australian Government, 2014).
Model improvements
The original model for calculating Tier 2 livestock emissions in the Agriculture
sector dates back to 2003. It had been developed using the computer language
Delphi, which is not in common use. During 2011 and 2012, the model for
calculating Tier 2 livestock emissions was converted from Delphi to Excel VBA. The
advantage of Excel VBA language is that it is more widely understood and available.
During the conversion, any noted errors in formulas and processes were addressed
and documented. Once the conversion was complete, a parallel run of the data
between the new and the original model could be done to test the data integrity.
The results obtained from running the same data set between the Delphi-based model
and the Excel VBA-based model as part of the model testing were used for the
reconciliation and validation process during development. Deloitte independently
reviewed the results of the reconciliation process undertaken by the model developer
as a part of its 2012/2013 review of the QA/QC practices for the Agriculture sector.
19
As there have been a number of changes arising from the migration to reporting to the IPCC (2006)
guidelines and applying AR4 GWPs to calculate CO 2 -e for non-CO 2 gases, this has not been
completed for the 2015 submission.
New Zealand’s Greenhouse Gas Inventory 1990–2013 139