ghg-inventory-1990-2013

6.6.4 Category-specific QA/QC and verification
Carbon dioxide emissions from the Grassland remaining grassland and Land converted
to grassland categories are key categories (level and trend). In the preparation of this
inventory, the data for these emissions underwent Tier 1 quality checks.
6.6.5 Category-specific recalculations
The impact of recalculations on net CO 2 -e emission estimates for the Grassland category
is shown in table 6.6.6 below.
Table 6.6.6
Recalculations of New Zealand’s net emissions from the grassland category in 1990 and
2012
Net emissions (kt CO 2 -e)
Change from the 2014 submission
Year
2014 submission 2015 submission (kt CO 2 -e) (%)
1990 +810.4 +1,104.3 293.9 36.3
2012 +5,368.7 +6,247.4 878.7 16.4
Note: The 2014 submission figures have been updated with the revised global warming
potentials from the Contribution of Working Group I to the Fourth Assessment Report of the
IPCC (IPCC, 2007) so vary slightly from those published in the 2014 submission. These
values also exclude emissions from liming at both dates.
These recalculations are due to updated activity data as discussed in section 6.1.4.
6.6.6 Category-specific planned improvements
There are no improvements planned for this category at this time.
6.7 Wetlands (CRF 4D)
6.7.1 Description
New Zealand has around 425,000 kilometres of rivers and streams, and almost
4,000 lakes that are larger than a hectare. Damming, diverting and extracting water for
power generation, irrigation and human consumption has modified the nature of these
waterways and can deplete flows and reduce groundwater levels. Demand for accessible
land has also led to the modification of a large proportion of New Zealand’s vegetated
wetland areas in order to provide pastoral land cover. Just over 10 per cent of wetlands
present prior to European settlement remain across New Zealand (McGlone, 2009).
Section 3.2 of GPG-AFOLU defines Wetlands as “areas of peat extraction and land that is
covered or saturated by water for all or part of the year (eg, peatlands), and that does not
fall into the Forest Land, Cropland, or Grassland categories.” (IPCC, 2006a, p 3.6). The
definition includes reservoirs as a managed subdivision, and natural rivers and lakes as
unmanaged subdivisions. Flooded lands are defined in GPG-AFOLU as (IPCC, 2006a,
p 7.19):
… water bodies where human activities have caused changes in the amount of
surface area covered by water, typically through water level regulation. ...
Regulated lakes and rivers that do not have substantial changes in water area in
comparison with the pre-flooded ecosystems are not considered as Flooded Lands.
New Zealand’s Greenhouse Gas Inventory 1990–2013 267