7. INVENTORY PROCESS TO MEET THESE REQUIREMENTS

To meet the needs of users, the collection of emissions data should progress in parallel with the development of the European inventory systems. The data collection needs to proceed in overlapping stages which are described below.

Figure 4 - Schematic Showing how Inventory Stages Relate to Each Other
(For clarity this is extended until the end of 1998).

7.1 Stage 1 - National Figures

This programme will have three steps:-

• Firstly some provisional data should be collected by six months after the end of the year.
• Then final data for the main sectors and pollutants should be collected over the next six months.
• The next year is then used to finalise all the results.

As the CORINAIR 90 software was designed for the compilation of a spatially disaggregated inventory it will not be immediately suitable for this task. Development work may enable this to be done but this will not be available before the end of 1995 at the earliest.

Initially this data collection should be based on existing national systems with the close support of the Emissions Inventory Topic Centre. There is no need to interfere with countries which have systems that already supply data on time. For them the Emissions Inventory Topic Centre’s role is limited to assisting the transfer of data to the Emissions Inventory Topic Centre and to ensuring consistency between countries. In the future consideration should be given to the provision of specific data collection or transfer tools for these countries. These would ensure the compatibility between countries in the data collected. Those countries that have used CORINAIR 90 to produce their national emissions may need a ‘cut down’ version to assist them in this programme.

The Emissions Inventory Topic Centre together with each member state will produce ‘default’ estimates in parallel to the one produced by the national experts. These will be based on international energy and industrial statistics. In the event that a national expert is unable to meet the deadlines in this programme this ‘default’ data will be used.

The data that countries have committed themselves to supplying was described in Section 5.3. This would be the minimum expected from countries.

7.1.1 Step 1 - the first six months

Countries prepare their provisional estimates of pollutant group 1 data (CO₂, SO₂ and NO_x). Where individual countries wish this could be based on their existing systems with the Emissions Inventory Topic Centre providing the help needed to make the results compatible with other countries. In the longer term data collection software could be considered. The Emissions Inventory Topic Centre will provide close support. This should speed up the process and will also ensure compatibility between each country’s submission.

Given the short timetable some of the data will need to be estimated. Therefore it is anticipated that most, if not all, of these datasets will be provisional.

In addition the Emissions Inventory Topic Centre will assist each member state to make separate estimates based on international energy balances and other data where necessary together with each member country.

These will be used as a comparison and verification with the countries’ own estimate as part of the validation process. In addition, in the event of a country not providing any data, these Emissions Inventory Topic Centre estimates could be used as default numbers.

This step will provide provisional emission estimates for each country within six months.

7.1.2 Step 2 - from July to December

The provisional inventories produced in step one will be refined and corrected to produce estimates of emissions at national level by the second level of the SNAP codes. This is the first subdivision of the eleven UNECE source sectors. IPCC reporting formats will also be needed. This will result in emissions of the main pollutants (pollutant groups 1 and 2) by the most important source sectors. Again this will need close support by the Emissions Inventory Topic Centre.

Again the Emissions Inventory Topic Centre will provide close support and help maintain the separate estimates based on international statistics produced with each country. These separate estimates could be used as a last resort.

7.1.3 Step 3 - the second year

Here the emphasis changes to refining the data already collected and to producing any greater detail that is required. Emission estimates of pollutant groups 1-3 will be provided.

The Emissions Inventory Topic Centre’s support will still be needed as well as its separate emissions estimates.

Stage 2 - Geographic Data

The collection of spatially disaggregated data should proceed in parallel. This will be based on the modified CORINAIR 90 software for Air Emissions ‘94. The importance on incorporating as much of the EMEP/CORINAIR guidebook as possible has been discussed above. The frequency of subsequent spatially disaggregated inventories should be agreed with the interested parties. There are a number of alternatives including:-

• Only repeating the whole exercise every five years. This is an essential minimum.
• Repeating the whole exercise at shorter intervals may be desirable.
• Doing a complete inventory every fourth year and extrapolating the results, based on national estimates and point source emissions to fill in the gaps.

The third alternative would require the least effort from each member state, but may result in their being little continuity in the compilation of the complete spatial datasets. Only if this alternative was desired by enough countries would specific tools be developed to assist in this process.

Much point source data has to be made available within the year following the emissions so it will be possible to update the major point sources each year.

To ensure that Air Emissions '94 is completed before the end of 1996 the Emissions Inventory Topic Centre will take a number of measures.

• It must provide close, one-to-one, help and assistance, not just on the software, but also on any problems with the methodology.
• It will ‘pre-fill’ the software with data based on the CORINAIR 90 contributions.
• It will assist in the production of estimated default datasets for countries that are unable to meet the deadlines alone.

7.3 Stage 3 - Development

In the longer term there are a number of areas in which the system needs to be developed. In order to meet the user needs for quick results it is proposed that little development is done before the start of Air Emissions '94. However it is very important that development of the methodology, software, verification and validation procedures proceeds at the same time as the other programmes to enable the production of efficient, user orientated emission estimates beyond Air Emissions '94.

The areas which need developments are:-

• SNAP90 codes. These need to be developed to include all the relevant sources. Additional pollutants will require that SNAP90 is extended. The nomenclature should be adjusted so that it is more in line with socio-economic statistics to aid in the analysis of the results. The identification of any abatement techniques used is also important. This needs to be developed in association with the work undertaken by EUROSTAT and the EEA both on the improvement of classifications and integrated inventories.

• Methodology. The methodology will need to continue to be developed. This will need to be done in line with the EMEP Task Force on Emission Inventories. The methods proposed in this Task Force guidebook should be adopted and refined. The guidebook will continue to be developed. The experience of Air Emissions '94 and other users will feed into a process of continuous development.

• National Estimates. The collection of national emission estimates described in Section 7.1 is initially based on existing national systems. It may be appropriate to construct tools to assist national experts in these activities. Any such tools will need to implement the recommendations of the EMEP/CORINAIR Emissions Inventories’ Guidebook. These should aim to lead to a ‘Emissions Inventory Topic Centre methodology’ which should be followed throughout Europe. They would aim to relieve the experts of the more simple data collection work and enable them to concentrate on improving the estimation methods by contributing their special national knowledge and perspectives.

• Software. The role of the software systems should be considered. How much should the distributed software do and how much should be performed centrally? If the scheme of the existing system is to be followed then there are a number of changes that should be made. These are changes that are beyond those that can be included in Air Emissions '94. These include, in addition to any changes to methodology, use of Windows, a wider range of data entry, more consistency checking and better compatibility with the EEA’s own database system. The software should also sum all the energy consumption accounted for in the emissions and so produce data that can be compared with an energy balance for each country. The software needs to integrate with other software tools constructed for specific purposes. This will be an invaluable tool for checking the completeness of the data. Given the range of alterations this is the time to consider a completely new software tool that can be distributed in place of the revised CORINAIR 90 software for spatial inventories beyond Air Emissions '94.

• COPERT. The COPERT software is in need of updating if only to include advances in our knowledge of emission rates and the more detailed methodologies being proposed by Germany and others. It is proposed that a small group similar to the original CORINAIR working group on road transport emissions be established. This should aim to collect necessary data and propose changes within six months (by September 1995). The COPERT software should then be updated in line with this by the end of December. It may be necessary to fund some individuals outside the topic centre to participate in the group and the alteration of the software should be the subject of a specific sub-contract from the Emissions Inventory Topic Centre.

• Other tools. There may be a need for other tools to assist national experts. For example, assistance with producing national totals (see above), checking, comparison and documentation. The tools discussed above should be considered for development either by the Emissions Inventory Topic Centre itself or as part of specific subcontracts.

• Validation. This is checking that the emissions data have been compiled in accordance with the agreed methodology. In other words "Has the methodology been followed?". This can be assisted with tools that check numbers are reasonable and compare them with default values.

• Verification. Verification is a series of checks that show that the emissions data are good estimates of the true emissions. In other words "Does the agreed methodology actually give good estimates of the true emissions?". These will need to be developed. The UNECE Task Force on Emissions Inventories has an expert panel on Validation and Verification and their ideas and suggestions should provide the basis for this.

All of the development work described above will need to take into account the requirements of integrated inventories.

7.4 Timetable

Table 11 indicates how the parallel processes of collecting national level and spatial data should proceed. At the same time the Emissions Inventory Topic Centre should be conducting a major review of the whole system including the software so that new software and updated methodologies will be ready for the next spatial inventory. Table 12 shows specific tasks which the Air Emissions Topic Centre will undertake and Table 13 the reports which the Topic Centre will produce on CORINAIR 90.

Table 11 - Timetable for the Emissions Inventory Topic Centre
(April 1995 to December 1996)

* It is anticipated that the final report on Air Emissions ‘94 will be published in April 1995

Table 12 - Timetable of Specific Tasks for the Emissions Inventory Topic Centre

Table 13 Timetable for Topic Centre Reports on CORINAIR 90

7.5 Products: The Supply of Information on European Emissions

These need to be designed in line with user needs so that the Emissions Inventory Topic Centre not only supplies data but summarises and analyses data to provide useful information. While updates to the estimates can be received by the Emissions Inventory Topic Centre at any time it is suggested that the information produced by the Emissions Inventory Topic Centre is updated at regular intervals (once or twice a year). This should eliminate confusion that would arise if the numbers were updated at random intervals.

There are a wide range of possible ways of presenting the data that will be collected. This needs to be collated and presented in suitable report formats so that useful information can be distributed. Examples of what could be produced are given below.

7.5.1 System Outputs

The inventory software should be able to produce summaries of the emissions in a number of formats. Formats that have already been suggested are:-

• EMEP/CORINAIR 11 source sector summaries;
• IPCC tables;
• By different SNAP code levels;
• Standard reports similar to those being produced for CORINAIR 90.

As the data should be available in a much quicker timetable these reports will be of much greater interest than for CORINAIR 90.

7.5.2 Emissions Inventory Topic Centre Data Outputs

The Emissions Inventory Topic Centre should supply its data to the EEA and other interested parties as soon as possible. In particular the data from the 1994 disaggregated inventory should be available before the end of December 1996.

The data can be distributed either as printed tables or in an electronic form. Some of the ways the data could be provided are described below:-

• Tabular data on paper. This is most suitable for short tables and summaries rather than the whole database.

• Tabular data on disks or tapes. This could include all the data.

• Data on CD-ROM. This is being considered for the EMEP/CORINAIR guidebook. The inventory could be distributed in this form together with any reports describing its construction.

• Network access to a main database. This could be provided across an international computer network, for example the Internet. This would need a central server and consideration given to the security aspects, but would enable users quick access to any updates and could be used to alert users to any changes in the status of any of the data.

• Data could be transferred from NUTS 3 regions to 50 x 50 km grids for use by EMEP and others.

The outputs would need to satisfy as far as possible all the user needs identified earlier inTable 3.

It may be useful to consider developing a standard format for emissions data provided on disk or tapes. There is already a DIN/ISO guideline on the transfer of air quality data, and this might provide a useful starting point.

7.5.3 Emissions Inventory Topic Centre Reports

Reports explaining the inventory results need to be produced. There will need to be at least one for the national totals at the beginning of 1996 and one fully describing the spatially disaggregated inventories in early 1997. (The data should be distributed in time for the deadline with some explanation but the full report can be produced within four months afterwards.)