99
In the first instance, countries should consult existing information sources to obtain
specific guidance on, for example, energy sector definitions and the recommended
emission estimation or measurement methodologies. Regarding the reporting of
inventories, estimations of data from previous years are typically subject to revision as
estimation methods become better and countries shift from using default emission
factors to country-specific factors.
To assess sustainability, ideally it would be possible to study the trends in emissions
over long time periods (e.g. 20 or 30 years). However, even within Europe, where air
pollutant emissions have been reported for a number of years, reported emissions for
years before 1990 are generally not complete and may also be unreliable due to the
non-availability of historical activity data, technology-specific emission factors, etc.
Time series reporting should therefore initially focus on accurate reporting from 1990,
the baseline reporting year for many international agreements.
Dostları ilə paylaş: