WP1: Emissions

Overview and background

Emissions of air pollutants cause air quality degradation and result in climate change. Reducing emissions is one of the most important options for abating these negative impacts. A proper knowledge of emission sources and their location in time and space is a crucial component of being able to modelling air quality and climate, predict their future change, and design feasible mitigation scenarios. Recently improved “bottom-up” emission inventories of various pollutants such as particulate matter (PM) and its carbonaceous components (black Carbon (BC) and Organic carbon (OC)) are better underpinned than before, and are more detailed, including technology differentiation. Some of these new emission inventories have been reduced down to nearly half of previous inventories, which, however, results in lower predicted concentrations by the models that are not supported by the observations at many locations. Major sources of uncertainty and error in emissions datasets include the use of incorrect “real-world” emission factors, emission measurement artefacts, missing or falsified information on activity data, and wrong assumptions about the hygroscopic nature of aerosols. More accurate emission inventories of e.g. carbonaceous aerosols (BC and OC) are prerequisite model inputs for quantification of the aerosol climate forcing, which is the largest uncertainty in estimating total anthropogenic climate forcing. To quantify and abate the adverse health impacts of air pollution, chemical speciation and source identification of particulate matter is essential. Currently it is widely acknowledged that the uncertainty in emission inventories is a key feature in the limitations of predictive modelling as well as mitigating adverse impacts of the emissions.

Methodology and advancement beyond the state-of-the-art

This WP will provide state-of-the-art regional and global emission inventories and high resolution emission maps, which will be available for community use after the project completion, and which are needed as model input for WPs 4, 5, 6 and 7. The emission inventories will be based on activities speciated according to fuel use, fuel type and technology, which will allow quantification and spatial allocation of emission reductions due to mitigation scenarios developed in WP8.

In order to advance beyond the current state-of-the-art in megacity emissions, improvements will be made in relevant emission characteristics, especially the spatial allocation of sources, chemical speciation of emissions, and resolution of the gridded emission maps. Special emphasis will be placed on the consistent integration of higher resolution megacity data into the lower resolution regional or global emission maps. To accomplish this, the work will be divided into seven tasks:

1) Global anthropogenic and natural emission inventories: Global emission inventories will be needed to model the impact of MCs. We will use current state of the art inventories for anthropogenic sources (e.g. the EDGAR information system, of which TNO and MPI are co-developers; the database developed in the framework of EU-IP RETRO (TNO); and the global carbonaceous aerosol inventory of Bond et al (2004)). The effort in this task concentrates on enhancing the resolution of the emissions data and nesting the case study cities accurately in the global database.

2) Regional Pan-European anthropogenic emission inventory : Complete Pan-European emission inventories and high resolution emission maps of primary anthropogenic pollutants at a resolution of about 6 x 6 km for the base year 2003 will be provided as inputs to the regional modelling activities in WP 5 and 6. Relevant emission characteristics important for improving the predictive capacity of the models will be improved and included where possible.

3) Development of a baseline scenario: Baseline scenario for the years 2020 and 2030 and a rough estimate for 2050 for Europe and for the case study megacities (Paris, London, Rhine-Ruhr, Po Valley, Mexico City) will be provided as a basis for the analysis of emission reduction measures and strategies in WP 8.

4) Case studies: High quality and high resolution city inventories will be compiled, based on existing information to the extent possible, and made available both as model input and a base for mitigation measures. The underlying activity data tables will be “translated” and linked in the various databases in order to be nested in a consistent way in the regional and global emission inventories.

5) European heat flux inventory: To assess the impact of heat flux from megacities on local climate a European anthropogenic heat flux inventory will be developed using the activity data and spatial distributions from task 2, working with heat flux factors developed in cooperation with WP2.

6) Validation, evaluation and improvement of EI’s: Task 1 and task 2 will start out with delivering a first working version of the desired inventories in the first year of the project. The EI’s will be further improved through: 1) feedback from modellers working with the EI’s; 2) A general review of regional source apportionment studies; 3) Validation through measurement data and source apportionment within WP3 and WP4.

7) Processing of emission inventories for model sensitivity and scenario runs: Emissions datasets will be provided for the sensitivity runs (WP5) and future scenario runs (WPs 5, 6 and 8). For the sensitivity runs, two types of emissions datasets will be provided: removing the total megacity emissions from the dataset, and redistributing a fraction of the megacity emissions into the surrounding regions.

FP7 EC MEGAPOLI, 2008-2011