4. Review of CORINAIR 90

4. REVIEW OF CORINAIR 90

A number of problems with CORINAIR 90 have been reported either by the EEA, data suppliers or users. These are described below. In some cases they have occurred because users’ needs have become more sophisticated since the original specifications for CORINAIR 90 were drawn up. Others draw attention to areas where the CORINAIR methodology and software need to be improved. In both cases, the Topic Centre must address these problems in AE 94 and subsequent inventories. Possible solutions to these problems are outlined here and discussed in more detail in Sections 7 and 8.

4.1 Software Usability

Several countries reported problems with the usability of the software - partly due to problems with the software itself, and partly due to inadequate descriptions of the software. Windows programs were requested by some users. The difficulties of transferring data files already on computers into a system requiring keyboard entry were discussed. While some countries had managed to transfer data files between their national systems and the CORINAIR system fairly easily, others had experienced considerable difficulties.

The software was designed to meet the needs of inventory ‘producers’; it is self contained so that a national expert can produce a national inventory on a PC, without any additional commercial software and without needing any specific knowledge about databases. The software collects base data, calculates emissions from that data, collects surrogate statistics for spatial disaggregation and then performs the disaggregation. However, before the EEA can exploit the data, it must be transferred to a more powerful computer and transformed into a relational ORACLE based database.

Possible improvements to the software are discussed further in Sections 6.3 and 7.3.

4.2 Urban/Regional/National Data.

The spatial disaggregation used by the system is based on ‘NUTS’ level 3 regions. These have the advantage that they are defined across the EU. However they may not be ideal for air pollution assessment. Since CORINAIR 90 was developed, concern for urban air pollution has increased, and some users now want urban inventories. This need may not be well served by the ‘NUTS’ level 3 regions in CORINAIR 90 unless they are coincident with them.

For example, the NUTS level 3 region for London (UK) or Milan (Italy) is more or less coincident with the urban area. However, in Spain the area that includes Barcelona also includes a large rural area. Thus the CORINAIR 90 inventory cannot be used to give good information about urban areas throughout the EU. As urban air quality is an important issue this is a serious problem.

Local inventories are being compiled for specific cities for specific projects across Europe. As well as the spatial differences in areas covered identified above, these may differ from CORINAIR 90 inventories in several other ways. For example, local inventories may:

• Consider additional pollutants, e.g. heavy metals, POPs, and particulates. These are which are not included in CORINAIR 90, but are of interest at a local level. NMVOCs may be considered in a speciated way.
• Consider linear sources such as roads, rivers and railways, and ‘localised’ sources as well as area sources and large point sources.
• Consider more detailed source categories.

The EMEP/CORINAIR Emissions Inventory Guidebook indicates that inventory methodologies can be extended to urban areas. There may be a role for the Emissions Inventory Topic Centre in urban inventories. There are several possible options. For example, the Topic Centre could:

• collect local inventories which are being compiled and make them available to users across Europe;
• consider checking the consistency of local inventories;
• consider providing guidelines for the production of local inventories to help ensure their compatibility with each other and with national inventories. For example the Topic Centre could define smaller areas which are subsets of NUTS 3 regions for use in local inventories.

Further discussion and guidance from the EEA is needed to determine the exact role of the Air Emissions Topic Centre in this area.

4.3 Comparisons with Energy Balances

It is not possible to use the CORINAIR 90 software to summarise the fuel used to estimate emissions for comparison with energy balances. This comparison is an important step in ensuring the completeness of an inventory as many of the pollutants are predominantly energy related. (Comparison with other statistics is needed for some pollutants e.g. agricultural data for NH₃.) It is a concern that this simple validation procedure was not possible within the software. One reason is that this need was not foreseen in 1990. It is essential that this comparison against international energy balances should be part of the verification process in any future system.

4.4 Prioritisation of Information.

There has been little attempt to prioritise the data requirements despite recommendations to do so. All the data has been input over three years (1992-1995) and the outputs are only available at the end of the entire process, while the data needs outlined in Section 5.3 are clearly staggered. One problem is that (as discussed in Section 3.3), experts may be reluctant to provide provisional figures which have not been officially agreed at a national level and so, even if provisional high priority data is available, it is not released until the end of the entire process. A method for prioritising data requirements is suggested in Section 6.

4.5 SNAP Codes

The SNAP codes were designed with atmospheric emissions in mind. They do not fit well with socio-economic statistics. This is a problem when the emissions data is combined with economic data to determine the feasibility of various strategies and policies. However, the standard socio-economic statistics cannot handle some emissions sectors in a practicable manner (e.g. road transport).

A further problem is that apart from large point sources the current system does not record abatement technologies very well. It is impossible to answer questions such as ‘If abatement technology x were imposed what effect would that have on emissions?’ or ‘What percentage of emissions are unabated?’ These are important questions if any assessment of possible control strategies is contemplated. CORINAIR 90 was not designed to be able to answer such speculative questions, but it should be considered whether future inventories should be able to meet these new user requirements.

‘Rubric’ codes provide a way of sub-dividing an area activity code. It is thus possible to use the ‘rubric’ codes to record abatement technologies for area sources. Rubrics can also be used to split SNAP activities into economic sectors, and this has been done by some countries (e.g. France). As there is no consistency between countries in their use, the potential of the ‘rubrics’ to address the issue of either abatement or socio-economic sectors has not been realised. It is not possible to use rubrics to solve both problems as the CORINAIR 90 software has only one rubric code per area activity. These areas need further investigation in order to find solutions.

4.6 CORINAIR Inconsistencies

An obvious inconsistency is that some countries do not provide estimates for some activities because, for example, data is unavailable either within the country or to the national expert. Another area of inconsistency is the treatment of other mobile sources. Some countries include these emissions under other headings.

There also appears to be some inconsistencies in the way in which countries reported CO₂ emissions in CORINAIR 90:

• some countries submitted estimates of CO₂ emissions as the actual emissions from the exhaust while others as the ‘ultimate’ CO₂ which assumes all the carbon in the exhaust will eventually be converted to CO₂.
• CO₂ emissions from biomass burning is another area of variation. Some countries include this while others exclude it. Most, if not all, of this emission is simply recycled carbon that is absorbed from the atmosphere into plants and foods that are then consumed.

These inconsistencies may be due to some experts using IPCC reporting conventions rather than the CORINAIR specification e.g. IPCC specifies the reporting of ultimate CO₂ while CORINAIR 90 specified end of pipe. We must be clear in our definitions. IPCC are developing guidelines on the treatment of CO₂ emissions and CO₂ sinks and it is proposed that the Topic Centre methodology follows these as far as possible.

Compatibility with the IPCC methodology is important. If Air Emissions 94 is to differ from the IPCC reporting format so that it meets other users needs, then it may be important to improve the existing IPCC/CORINAIR interface, so that IPCC compatible data can be extracted from CORINAIR quickly and easily. This will require some extra information to be collected due to the different coverages of the two inventories.

The general differences between the source categories used in the IPCC reporting format and CORINAIR 90 are shown in Table 6. A specific comparison for the UK is shown in Table 7. Further details of some of the inconsistencies in the CORINAIR 90 treatment of CO₂ emissions and differences between IPCC and CORINAIR 90 are given in Box 2.

Table 6 Correspondence between IPCC and CORINAIR Main Source Categories

Table 7 Comparison of IPCC and CORINAIR Data for UK 1990 CO2 Emissions (kTonnes as CO2).

Box 2 Inconsistencies in the Treatment of Greenhouse gases

4.7 Confidentiality

Data may be confidential for a number of reasons, particularly legal requirements. However, confidentiality in emission inventories defeats some of the aims of the whole exercise. If the data that has been collected cannot be distributed to all users it is worthless. It had therefore been proposed that no confidential data should be collected. This was not accepted. There are a range of national approaches to confidentiality and some of these are discussed in Box 3.

A complex system of flags was incorporated into the CORINAIR 90 software which shows exactly which parts of the data are regarded as confidential. This enables each country to adopt a different approach. These flags are entered by each county at the same time as the data is collected. However some countries have flagged data differently to the general, written, descriptions of their confidentiality requirements. The EEA is taking the flags as the precise description of the confidential data.

4.8 COPERT

COPERT is a separate software tool that implements the recommendations of a CORINAIR working group on emission factors for calculating emissions from road transport. COPERT was used by some countries and not others; some used it as a check on their national methodology. (Box 4 gives examples of national approaches). COPERT is also used in other European activities (e.g. FORMOVE and CASPER)

It is important that variations in emission estimates reflect real differences between countries and not differences between methodologies. Road traffic emissions are an important source of several pollutants, and estimating traffic emissions is complex. It thus seems logical to retain COPERT as a default tool for countries to use if they wish to. It is not intended that it should replace more sophisticated national approaches.

Box 3 Examples of National Approaches to Confidentiality

Box 4 Examples of National Approaches to COPERT

The COPERT methodology is in need of updating for two main reasons. Firstly, the European vehicle fleets have changed since 1989 when it was compiled and the methodology should change in line with this. Secondly, there have been a range of measurement programmes across Europe that have examined particular features of vehicle emissions such as cold starts, evaporative emissions, low speeds and temperature effects. These should also be included.

The COPERT software was a different style to CORINAIR 90. It was based around a spreadsheet and thus enabled entry directly into tables. Some preferred it and others did not. The software itself is in need of updating to become a more modern easy to use tool.