Teorías del desarrollo

8.4 Nitrogen flows in EU as a result of agreed or scheduled steady-state situation, ktonnes N/year and percentages.

current regime Nitrogen budgets economic inflow economic outflow - air - surface water - - landfill in - - groundwater crop/grass production problem

atm. dep. on non-agr. soils leaching to groundwater

inflow to North Sea ocean) 18789 5710 13079 - 5572 - 2260 - 3603 - 1517 5478 - 961 - 4502 14444 1285 1503 scheduled relative policy regime change

17841 7028 10813 - 4248 - 1068 - 3674 - 1824 5010 - 486 - 4525 14293 1058 4525 796 (-18%) (-47%)

Figure 8.4 shows the SFD for the long-term steady-state nitrogen flows resulting from the aforementioned changes in the nitrogen regime. In Table 8.4, the figures are compared with the long-term steady-state nitrogen flows anticipated with a continuation of the present regime. These latter figures differ only slightly from the present situation because the economic nitrogen cycle is rather short: the life cycle for most nitrogen applications is completed within a year.

From Figure 8.4 and Table 8.4 it can be concluded that current and scheduled measures have a favourable impact on nitrogen management in the EU. On the whole, the economic inflow items in the SFD have decreased a little by the assumption of cleaner combustion processes, causing less formation of NO, from The economic outflow is higher as a result of increased 'economic due to the assumptions regarding in sewage treatment plant. A decreased inflow and an increased outflow result in an aggregate decrease in emissions, and in greater economic efficiency of nitrogen use since all production remains practically at the same level. The efficiency of agricultural nitrogen use hardly seems to be influenced.

For the North Sea, the 50% immission reduction target is almost achieved. The measures (and especially the assumption concerning sewage treatment) are therefore almost sufficient; there may still be implementation problems but these are not discussed here. The acidification problems will not be solved by a 30% emission reduction: a reduction in the atmospheric deposition of is expected. We can detect two cases of problem- increased leaching to groundwater, leaving this problem flow unsolved, and more landfill, which in itself may not be problematical, but which will inevitably lead to greater nitrogen losses, mostly to the atmosphere and to the groundwater, on the local level. On the the proposed policy measures do not satisfactorily solve nitrogen-related problems, even full implementation is assumed. This is not surprising if it is matched with the results of the analysis: the agricultural flows, including the use of fertilizer, are the main cause for the but are virtually unimpaired. Since the policy measures do not sufficiently influence the origins of the problems either directly or indirectly, it is inevitable that a shifting of Problems will occur.

and discussion

Environmental problems related to nitrogen compounds occur at various scale levels. These Problems have been treated as nitrogen budget problems and have been analyzed comprehensively. technique of Substance (SFA), implemented in the computer program SFINX, has been used for this analysis. By describing and modelling the EC as a system of interdependent flows, is has proven possible to connect separate nitrogen related problems to their origins, and to estimate the effectiveness of certain abatement measures for those

as well as the shifting of problems that may occur.

the immediate causes of the separate nitrogen related problems vary a great deal, three problem flows can be traced back to the same ultimate origins. The atmospheric of and the leaching of nitrates to groundwater, and the anthropogenic input to the North Sea can all be attributed to the import and production of fertilizer.

food production and consumption sectors can be viewed as the sectors most responsible for problems. Although the problems occur on various scale levels, the most causes are regulated on the EC level: the EC Common Agricultural Policy.

States as well as by various international bodies. The most important international measures are formulated in the EC Nitrate Directive, and in the agreements and proposals for the protection of the North Sea. The changes in the CAP according to the Plan do not directly affect the agricultural nitrogen flows in a significant manner. The environmental problems are thus not so much related to overproduction, but to the CAP goal of self-sufficiency itself. Most measures under the various existing policies and agreements are of a

pipe nature. If these are implemented adequately, two of the three selected problem flows are expected to decrease significantly but in neither case enough to solve the problem completely. The third problem flow, the leaching of nitrates to groundwater, will remain wholly unsolved. This is due to the fact that the most important origins, the nitrogen flows in agriculture and ultimately the addition of nitrogen to the system in the form of industrial fertilizer, are not significantly influenced.

To adequately solve all three nitrogen-related problems, therefore, other measures will be necessary, and are conceivable. This is the subject of Section 8.2 of this chapter, wherein both stringent technical possibilities and major changes in agriculture will be scanned on the implications for the environment and for society.

8.1.8 Summary

The EU is faced with major environmental problems related to nitrogen compounds. The origins of three such problems, the atmospheric deposition of the leaching of nitrates to groundwater, and the anthropogenic N-input to the North Sea, are investigated by means of a Substance Flow Analysis (SFA). Although the problems occur at various scale levels and have varying direct causes, the food production and consumption cycle can be appointed as the main responsible sector, and the production and import of fertilizer appears to be the major ultimate source in all three cases.

Measures to combat these problems have been agreed on in various international frameworks: the EC, the International North Sea Conference and the Rhine States conference. These measures include technical emission reduction for acidifying compounds resulting in a 30% emission reduction, extension of the sewage treatment network and application of with 50% effectiveness, and introduction of measures directed at efficiency increase and emission reduction in agricultural practice in 10% of the agricultural area. The recent changes in the CAP are not expected to lead to significant changes in nitrogen flows. Assuming full implementation, an almost sufficient 45% reduction is expected for the anthropogenic nitrogen flow into the North Sea. The atmospheric deposition of nitrogen compounds will be reduced by approximately 20%. The leaching of nitrates to the groundwater is expected to remain at the current level or even to increase a little. In all, these measures lead in the right direction but do not satisfactorily solve the three problems, mainly because the ultimate origins of the problems are not sufficiently influenced and measures therefore inevitably result in a shifting of problems.

8.1.9 References

ANONYMUS (1993). in binnenwateren eist verdere van

nutriënten en aanvullende maatregelen (Abating eutrophication demands a further reduction of nutrients and additional measures). 26 (4), pp 84-5, illustr.