A few years ago, while evaluating the environmental improvements that are expected to result from the revised Gothenburg Protocol by 2020, scientists at the CCE made a rough estimate of what additional reductions in acidifying and eutrophying emissions are needed to achieve levels of depositions that no longer exceed the critical load limits.
This was done using the very simplified approach of assuming uniform (same percentage) gradual emission reductions for all European countries and for international shipping. The starting point was the emission levels projected for 2020, assuming full implementation of the revised Gothenburg Protocol.
For eutrophication it was shown that an additional 70 per cent reduction in total nitrogen emissions (nitrogen oxides and ammonia) would bring the exceedance of the critical loads for nutrient nitrogen close to zero. The total area at risk of eutrophication in Europe would still cover about two per cent, but the magnitude of exceedance in these areas would be quite low.
As regards acidification, exceedance of the critical loads approached zero at an additional 60 per cent combined reduction in emissions of sulphur dioxide, nitrogen oxides and ammonia. The remaining area at risk in Europe would come down to less than one per cent.
No detailed analysis was made regarding the locations of the remaining areas at risk (e.g. their spread between countries) or what types of ecosystems (e.g. nature protection areas) would still be exposed to excess deposition.
Source: CCE Status Report 2012, link: www.wge-cce.org/Publications/CCE_Status_Reports/Status_Report_2012