When compiling an inventory it is important to use
a consistent methodology. The GRIP inventory approach is intended for use by regions, States, and other spatial scales wishing to monitor their emissions and gain an insight into emissions drivers. The GRIP approach also enables inter-regional and year-on year comparisons, all delivered in a cost-effective, user friendly manner. The methodology and tools can be viewed via www.grip.org.uk
GhG emissions inventories have been produced at
the sub-national level in many different areas. These inventories have been carried out by a range of
bodies that have included consultancies, academics and representatives of the areas. One of the consequences of the broad spectrum of organizations engaged in inventory compilation at a sub-national level, is a breadth of different approaches to emissions estimation. These differing approaches have resulted in, some inventories omitting certain emission sources, with others taking differing views when assigning emissions from the generation of electricity, attributing them to either the location of the power station (source) or the area where the electricity is consumed (the end user). More generally, some approaches
use detailed data sets, whereas others employ a purely top down approach to inventory development – where national data is disaggregated to the regional scale by using an appropriate scaling factor, such
as population. It is often difficult to decipher which inventories are the more reliable without reading detailed reports.
These inconsistencies are magnified by disparities
in the availability of relevant data, as well as the accessibility of data sources and the depth of understanding regarding GhG emissions and their sources on the part of the person compiling the inventory. The upshot of all this is a degree of mistrust in the resultant emission figures and inventories
as the disparate approaches make it difficult to make meaningful comparisons and evaluations between areas, year-on-year, or wider national and international inventories.
In order to overcome these issues and to minimize any mistrust, uncertainty and misunderstandings, GRIP uses a consistent methodology over three
data levels for each source of GhG emissions. The GRIP approach takes into account the guidelines provided by the Intergovernmental Panel on Climate Change (IPCC) which governs inventory compilation on a national scale. In addition, GRIP has also taken account of other methods explored internationally at a sub-national level.
The GRIP approach is based on five critical principles, making it:
Timely in its approach;
Adaptable to available data sets;
Transparent in nature;
Easily replicable; and
Presented with a consistent reporting structure.
As already stated GRIP delivers these guiding principles through a practicable inventory methodology that spans three levels of data intensity, each with its own prescribed level of uncertainty.
The system is designed to negate double counting and is intrinsically programmed to accommodate differing levels of base data accuracy by utilizing its integral uncertainty functionality. This allows GRIP to be applied in areas which have different levels of data availability.
The mechanism is available on-line at www.carboncaptured.org.uk and comes complete with clear instructions, tips on how best to access data sources and a common reporting format for ease of cross comparison. It is available at very low cost for use by public and voluntary bodies, making it a cost effective alternative to other inventory packages.