The starting point for this educational exercise is the Kyoto Protocol to the United Nations Framework Convention on Climate Change [UNFCCC]. The exercise centers on a tool which allows assessing changes in the national emissions of greenhouse gases [GHGs] in lieu of their uncertainties.
The assessment of GHG emissions and removals is high on political and scientific agendas. Policy-makers use GHG inventories to develop strategies and policies to reduce emissions and to track the progress of these measures. However, GHG inventories contain uncertainties with far-reaching scientific, political and economic implications. At present, Parties to the UNFCCC are encouraged, but not obliged, to report uncertainties associated with GHG emission estimates. Inventory uncertainty is monitored, but not regulated, under the Kyoto Protocol.
Given this setting, the purpose of this exercise is very specific: It shall help a user get a grip on uncertainty and understand its impact on I) compliance and II) the amount of emission permits that can be traded under the Kyoto Protocol.
The tool allows a user to analyze by means of two techniques emission changes in lieu of their uncertainty. Spatially, the changes in emissions refer to the country scale; and temporally to the changes I) that countries have agreed to meet by 2008/12, the first commitment period of the Kyoto Protocol [Track I: compliance mode]; and II) that countries report annually with reference to 1990, the base year under the Kyoto Protocol [Track II: monitoring mode].
Irrespective of the track (compliance or monitoring mode) followed, two analysis techniques are used. The two techniques differ but they follow the same idea: Inventoried emissions of GHGs are uncertain, and this uncertainty translates into a risk that true emissions are greater than those estimated and reported. To compensate for, or even reduce, this risk a safety margin (or undershooting) is considered. For a given risk, the safety margin differs depending on the selected analysis technique. The first technique follows the undershooting [Und] concept which accounts for uncertainty at two points in time; while the second follows the combined undershooting and verification time [Und&VT] concept which accounts for uncertainty at one point in time. The major characteristics of the two techniques are listed below and their mathematical background can be found here.
|Taken into account by the technique||Und||Und&VT|
|Emissions difference between t1 and t2|
|Emissions gradient between t1 and t2|
|Risk with reference to the concept of significance|
|Risk with reference to the concept of detectability|
The most important assumption for using this tool is that no gap exists in accounting GHG emissions bottom-up and top-down. This condition follows the concept of dual-constrained full GHG accounting. Of the many sources of GHG emissions, emissions of CO2 from fossil fuel burning are the largest and most important in terms of impact on the climate, and they have the lowest quantitative uncertainty. How certain, then, are our best numbers of GHG emissions? Information on the uncertainty of CO2 emissions estimates can be found here. Other conditions under which the tool is used are listed below.
|With reference to||Condition of use|
|Countries/groups of countries||as listed in Annex B to the Kyoto Protocol, including the ‘old’ EU Member States collectively (EU-15)|
|GHGs||as listed in Annex A to the Kyoto Protocol, but only collectively (in CO2-eq) and not individually|
|Not taken into account||1) Land use, land-use change, and forestry [LULUCF]|
2) the so-called Kyoto mechanisms
|Uncertainties||refer to an equal-sided confidence interval of 95% (following the concept of a normal distribution) and are classified in relative terms according to the following intervals (in %): 0 , 5[; [5 , 10[; [10 , 20[; [20 , 40[; and >40%|
To facilitate calculations, only the medians of these intervals are used (exception: Class 5 is represented by 40%, its lower boundary).
|Data from||European Environment Agency (EEA)|
Note: The EEA produces Community-wide GHG inventories on a rolling basis and releases these officially with a time lag of two and more years (see also here). This explains a time lag of about three years in the data that we use in our emissions-change-versus-uncertainty analyses.
Last edited: 22 July 2013
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