CLIMATE CHANGE

6.0 GHG EMISSION INVENTORY

6.1 Emission Inventories

An emission inventory is an accounting of the amount of air pollutants discharged into the atmosphere. It is generally characterized by the following factors :

· the chemical or physical identity of the pollutants
·the geographical area covered,
· the institutional entities covered,
· the time period over which emissions are estimated, and ·
the types of activities that causes the emissions.

Emission inventories are developed for a variety of purposes such as inputs to air quality models, to develop strategies for policy makers, track progress of standards, and by facilities & regulatory agencies to establish compliance records with allowable emission rates.

6.2 Measuring and forecasting greenhouse gas emission and sinks

A national inventory of GHG emission and sinks is a useful tool for both establishing baseline level for GHG emission, and for identifying options for GHG reductions. Forecasting future level of GHG emissions could serve as a benchmark against which future emission reductions could be measured.

The first step to address climate change is to identify all source categories that emit GHGs, and determine their current emission levels. By developing an inventory of GHG emissions, it is possible to identify those source categories that contribute the most to global warming. The inventory can also be helpful for identifying options for GHG mitigation policies.

The concept of baseline (or reference case) for GHG emission; methods for forecasting reference case emissions and policy - induced emission reductions; and the potential for "leakage" of GHG emission (i.e GHG emission increases in one sector that result from GHG reductions in another sector) etc. should form the basis for evolving any future forecasting procedures.

Two alternatives may be adopted to project the level of GHG emission reduction viz:

· relative to a static baseline (i.e 1990 level)
· relative to a forecasted level of emissions.

However, forecasting of GHG emissions has a wide range of uncertainty. Given the degree of uncertainty associated with existing methodologies and available data, projections may not serve any useful purpose. The maximum time frame for projecting emissions in most situations is likely to be 15 - 20 years, the typical time frame for energy use projections. Beyond that, uncertainties in technological changes alone may call into question the accuracy of forecasts.