Independent checks for validation of CH4 emission estimates

The agreed emission reductions in the Kyoto Protocol require methods to establish the quality and accuracy of the in-ventory data and to monitor compliance with the Protocol. The IPCC Expert Meeting in November 1997 in the Nether-lands concluded that an assessment of inventory data quality was strongly supported by independent checks and addi-tional analysis of uncertainties in the emissions inventories

Independent checks for validation of emission estimates: the metdat example for methane

The agreed emission reductions in the Kyoto Protocol require methods to establish the quality and accuracy of the inventory data and to monitor compliance with the Protocol. The IPCC Expert Meeting in November 1997 in the Netherlands con-cluded that an assessment of inventory data quality was strongly supported by in-dependent checks and additional analysis of uncertainties in the emissions invento-ries

On the importance of incorporating forest edge deposition for evaluating exceedance of critical pollutant loads

The concept of critical load (CL) was defined to express the tolerance of natural and semi-natural habitats for anthropogenic air pollution. Correct evaluation of the exceedance of critical loads is fundamental for the long-term protection of ecosystems by limiting emissions of potential acidifying and eutrophying pollutants. For forest ecosystems, the exceedance of critical loads is often calculated using deposition data measured in the forest interior. However, several studies report forest edges acting as 'hotspots' of acidifying and nitrogen deposition, showing up to four-fold increases in atmospheric deposition compared to the forest interior. This paper estimates the relevance of considering the higher deposition load in forest edges for calculating exceedance of critical loads for nitrogen and potential acidifying deposition. If measures to control and reduce atmospheric deposition are based on mean deposition fluxes within forest stands, deposition reductions will not be enough for preventing adverse effects. In fact, emission reductions should be adjusted to deposition values at the forest edge, since these zones are most threatened. We thus conclude that there is an urgent need to reconsider the calculation of exceedance of critical loads, taking into account edge enhancement of deposition. This is an issue of high relevance, particularly in highly fragmented regions, such as Flanders (Belgium)

Assessment of the exposure and loads of acidifying and eutrophying pollutants and ozone, as well as their harmful influence on the vitality of the trees and the Speulder forest ecosystem as a whole

Within the framework of the Dutch Priority Program on Acidification, 10 yr of research was conducted in a Douglas fir stand at Speulder forest. Research was conducted to establish the loads and levels of acidifying and eutrophying pollutants and ozone, to determine forest vitality characteristics and follow growth parameters and nutrient status in time and to determine the effects of reduction of loads and levels by manipulation experiments. Results indicate that during the last 20 yr critical levels for air pollutants have hardly been exceeded except for ozone, which slightly affected assimilation. Elevated nitrogen deposition has caused several adverse effects including (i) inhibited mycorrhizal development, leading to a decreased base cation and phosphorus uptake; (ii) elevated foliage/root (fine and coarse) ratios, making the forest more sensitive to drought and windthrow; (iii) elevated nitrogen and arginine concentrations in the foliage, associated with relative base cation and phosphorus deficiency, and (iv) elevated nitrate leaching polluting the groundwater. High inputs of acidity have caused elevated ratios of Al to base cations, affecting fine root (uptake) and depletion of the readily available Al pool, thus affecting the long-term sustainability. Despite these effects, forest vitality, in terms of defoliation/discoloration, is reasonable and forest growth even increased in response to nitrogen. The exceedances of critical loads for nitrogen and acidity, however, implies a (large) risk for the long-term sustainability of the Speulder forest

Overview of greenhouse gas emission databases and validation activities in The Netherlands

An overview is presented of the Dutch emission registration activities with respect to greenhouse gases. This in-cludes the Dutch Pollutant Emission Register (PER) and the global Emission Database for Global Atmospheric Re-search (EDGAR). Objectives. tanks. methods and information systems present in PER and EDGAR are highlighted. Special attention is given to methods used to derive greenhouse gas emissions from biogenie sources in agriculture. Within the tramework of the Dutch National Research Programme on Global Air Pollution and Climate Change, a project has been initiated to establish and validate a detailed CH4 emission database for the Netherlands and North-western Europe (MEI DAT). Methods and results of this project are presented as wen, again focusing of emission from biogenic sources in agriculture. The METDAT emission database is validated using model and measurement resuits of CH.1 air concentrations. Moreover. an assessment is made of differences with official emission data pub-lished in so-called Nationai Communications of the different countries. An outlook is given on near-future activities in relation to PER. EDGAR and METDAT. respectively

Deposition of acidifying components and base cations in Germany in the period 1987-1995

This report describes the results of the project: 'Deposition of acidifying components and base cations in Germany in the period 1987-1995'. The project was carried out by RIVM on behalf and for account of the National Environmental Agency 'Umweltbundesamt' (UBA) in Germany in co-operation with TNO and Alterra in the Netherlands. For Germany, the research carried out has yielded, as main product, estimates of dry deposition with a high spatial resolution. These, in combination with wet deposition data, will be used for calculating critical load exceedances. The basic model used in this study is EDACS, which calculates dry deposition fluxes on the basis of meteorological data and atmospheric concentrations of relevant species. Atmospheric concentrations were taken from results of the EMEP model (SO_2 and NO_x), the EUTREND model (NH_x) and wet deposition measurements (base cations). SO_x dry deposition fluxes were largest in eastern Germany; NO_y fluxes in central-west Germany and NH_x fluxes in north-west Germany. The highest dry deposition of potential acid (up to 20,000 eq ha"-"1y"-"1 as average for the period 1987-1989) was calculated for eastern Germany and the highest dry deposition load of nitrogen (up to 3500 eq ha"-"1 y"-"1 as average for the period 1987-89) for North Rhine-Westphalia. Dry deposition of SO_x, NO_y, NH_x and potential acid in the period 1993-95 decreased by 49%, 13%, 21% and 42%, respectively, compared to the 1987-89 period. Dry deposition of non-sea-salt Ca"2"+, K"+, Mg"2"+ and base cations decreased in the 1993-95 period by 42%, 24%, 65% and 43%, respectively. On average, the modelled dry deposition of NH_x, Mg"2"+, Ca"2"+ and K"+ can be concluded as not significantly different from dry deposition derived from throughfall measurements, although a considerable scatter can be observed. The comparison reveals an overestimation of the dry deposition of SO_x, NO_y and Na by factors of 1.67, 1.58 and 1.75, respectively. (orig.)Available from TIB Hannover: RN 8908(2000,81) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLENational Inst. of Public Health and Environmental Hygiene (RIVM), Bilthoven (Netherlands)DEGerman