RAINS-Europe online

Environmental Impacts

The RAINS Scenario Analysis Web tool provides the means to examine some of the environmental consequences of a given emissions scenario. The "Environmental Impacts" section of the menu shows the options available for the selection and display of various environmental impacts. It is possible to examine not only the impacts for a given set of emissions but also the differences in impacts between two different emission scenarios.

Environmental Impacts

N.B. The environmental impacts available from this tool are based on sets of data - atmospheric transfer matrices, critical loads - compiled for scenario analyses performed during the preparations for the UNECE CLRTAP Gothenburg Protocol to Abate Acidification, Eutrophication and Ground-level Ozone and the EU National Emissions Ceilings Directive (2001/81/EC).
New sets of data - with a grid resolution of 50km x 50km - will be prepared for analyses to be carried out under the EU Clean Air for Europe (CAFE) programme.

Acidification/Eutrophication

The RAINS model incorporates databases on critical loads and critical levels compiled at the Coordination Center for Effects (CCE) at the National Institute for Public Health and Environmental Protection (RIVM) in the Netherlands (Posch et al., 1997, 1999). These data are employed in integrated assessment modelling through the use of critical load functions, which provide the cumulative distribution function of the critical loads for all ecosystems of each 150km x 150km EMEP grid cell, as outlined in the Sixth Interim Report to the European Commission, DG-XI.

Having calculated the deposition resulting from a given set of emissions, it is possible from the critical loads information to derive the following impact indicators for each grid cell:

• the excess deposition for a selected ecosystem (e.g., for the two percentile);
• the percentage of ecosystems which experience deposition below their critical loads (i.e., the ecosystems protected against acidification or eutrophication);
• the total excess deposition (above the critical loads) accumulated for all ecosystems in a grid cell. Starting from a given deposition, this accumulated exceedance (AE) is calculated by adding up (for each ecosystem) the sulphur and nitrogen reductions needed to achieve non-exceedance by taking the shortest path to the critical load function.

A summary of Critical Load Exceedances and Gap Closure Methods provides further details of these different approaches to calculating critical load exceedances and their use in integrated assessment modelling. The RAINS Scenario Analysis Web tool provides estimates of the second and third of these three measures.

Ozone

For tropospheric ozone the RAINS Scenario Analysis Web tool uses source-receptor relationships between the precursor emissions (NOx and VOC) and ozone concentrations (or AOT values) derived from the EMEP Lagrangian Photo-oxidant model with a grid resolution of 150km x 150km. This entailed the development of a regression model based on the results of several hundred runs of the EMEP photochemical model. A brief description of the regression model is given in the Sixth Interim Report to the European Commission, DG-XI. The EMEP model runs were performed for five different meteorological years (1989, 1990, 1992-1994), and mean AOT values refer to means over these 5 meteorological situations. A single set of AOT40 regression coefficients was calculated to provide an estimate of the AOT40 5-year mean value directly, whereas for AOT60 regression coefficients were calculated for each of the five years individually, with the mean AOT60 being taken as the mean of the individual year estimates.

Environmental Impact Options

A number of options are available to examine the impacts on acidification, eutrophication and ground-level ozone:

A particular impact indicator may be displayed as a map or used to calculate an appropriate "exposure index" for each country. The following exposure indices may be examined:

There are two options for the display of environmental impacts:

	the relevant emission values displayed in the form (on the main page) are used to calculate the selected environmental impact which will be displayed on a map using a 150km x 150km grid.
	the relevant emission values displayed in the form (on the main page) are used to calculate country-specific exposure indices appropriate to the selected environmental impact, which will be displayed in tabular form.
N.B. The emission values from the form used for the impact calculation are "remembered" and will be used for any subsequent deposition or environmental impact calculation until replaced by the emissions of a newly selected scenario or emission field.

Additional Features

• Moving the cursor over a map causes the grid coordinates and calculated environmental impact of the grid square under the pointer to be shown.
• The data displayed in a map or the tabulated exposure indices may be downloaded to a local text file using the link provided below the map/table.

Environmental Impact Differences

It is also possible to examine the differences between the environmental impacts calculated for the "current" set of emissions - the latest displayed in the form - and those calculated for a selected existing emission field ("previous"). The differences displayed are simply calculated as "current" - "previous".

There are two options for the display of environmental impact differences:

	the relevant emission values displayed in the form (on the main page) are used to calculate the difference in the selected environmental impact, which will be displayed on a map using a 150km x 150km grid.
	the relevant emission values displayed in the form (on the main page) are used to calculate country-specific exposure index differences, which will be displayed in tabular form.
N.B. The emission values from the form used for the impact calculation are "remembered" and will be used for any subsequent deposition or environmental impact calculation until replaced by the emissions of a newly selected scenario or emission field.

Additional Features

• Moving the cursor over a difference map causes the grid coordinates and calculated environmental impact difference of the grid square under the pointer to be shown.
• The difference data displayed in a map or the tabulated exposure index differences may be downloaded to a local text file using the link provided below the map/table.

References

Posch, M., J.-P. Hettelingh, P.A.M. de Smet, R.J. Downing (eds.) (1997). Calculation and mapping of critical thresholds in Europe. Status Report 1997, Coordination Center for Effects, RIVM, Bilthoven, The Netherlands.
Posch, M., P.A.M. de Smet, J.-P. Hettelingh, R.J. Downing (eds.) (1999). Calculation and mapping of critical thresholds in Europe. Status Report 1999, Coordination Center for Effects, RIVM, Bilthoven, The Netherlands.
WHO 1997. Air Quality Guidelines for Europe. Second edition, Copenhagen.

Responsible for this page: Chris Heyes