3 research outputs found
Impacts of Air Pollution on Freshwater Acidification under Future Emission Reduction Scenarios; ICP Waters contribution to WGE report (ICP Waters report 108/2011)
The UNECE Convention on Long-range Transboundary Air Pollution (LRTAP) is currently working on a revision of the Gothenburg protocol. ICP Waters has used the dynamic model MAGIC to evaluate the effects of future deposition scenarios (COB2020 (current legislation), Low*2020, Mid*2020, High*2020, and MFR2020 (maximum technically feasible reduction) on surface waters. These five deposition scenarios are very similar to one another and represent substantial decreases in deposition for the year 2020 relative to the base year 2000. At all sites the modelled results indicate that chemical recovery will continue into the future. At all but the most acid sensitive sites acid neutralising capacity (ANC) will increase to levels above the critical level for biological damage. Additional improvements in water quality can be obtained in the future with emission reductions beyond MFR2020.Norwegian Climate and Pollution Agenc
Trends in surface water chemistry in acidified areas in Europe and North America from 1990 to 2008
Acidification of lakes and rivers is still an environmental concern despite reduced emissions of acidifying compounds. We analysed trends in surface water chemistry of 173 acid-sensitive sites from 12 regions in Europe and North America. In 11 of 12 regions, non-marine sulphate (SO4*) declined significantly between 1990 and 2008 (−15 to −59 %). In contrast, regional and temporal trends in nitrate were smaller and less uniform. In 11 of 12 regions, chemical recovery was demonstrated in the form of positive trends in pH and/or alkalinity and/or acid neutralising capacity (ANC). The positive trends in these indicators of chemical recovery were regionally and temporally less distinct than the decline in SO4* and tended to flatten after 1999. From an ecological perspective, the chemical quality of surface waters in acid-sensitive areas in these regions has clearly improved as a consequence of emission abatement strategies, paving the way for some biological recovery