Ing-Marie Gren

Resilience in natural and socioeconomic systems

We, as a society, find ourselves confronted with a spectrum of potentially catastrophic and irreversible environmental problems, for which conventional approaches will not suffice in providing solutions. These problems are characterized, above all, by their unpredictability. This means that surprise is to be expected, and that sudden qualitative shifts in dynamics present serious problems for management. In general, it is difficult to detect strong signals of change early enough to motivate effective solutions, or even to develop scientific consensus on a time scale rapid enough to allow effective solution. Furthermore, such signals, even when detected, are likely to be displaced in space or sector from the source, so that the motivation for action is small. Conventional market mechanisms thus will be inadequate to address these challenges.

Primary and Secondary Values of Wetland Ecosystems

Wetlands are continuously degraded in many parts of the world. One reason is the lack of the appropriate valuation of the multifunctionality of wetland. In an attempt to improve the understanding of the importance of this feature of wetlands an alternative classification of values is suggested; primary and secondary values. Primary value refers to the development and maintenance of ecosystems — their self-organizing capacity. Secondary values are defined as the outputs, life-support functions and services, generated by wetlands. Methods for measuring these values are discussed. Three case studies are presented which use different valuation methods and which to different degrees capture the primary and secondary values. It is concluded that only part of the total wetland value can be captured in monetary terms.

Managing nutrient fluxes and pollution in the Baltic: an interdisciplinary simulation study

Abstract This interdisciplinary paper reports the results of a study into the costs and benefits of eutrophication reduction in the Baltic Sea. A large multidisciplinary team of natural and social scientists estimated nutrient loadings and pathways within the entire Baltic drainage basin, together with the costs of a range of abatement options and strategies. The abatement cost results were compared with clean-up benefits on a basin-wide scale, in order to explore the potential for international agreements among the countries which border the Baltic. Most countries would seem to gain net economic benefits from the simulated 50% nitrogen and phosphorus reduction policy.

Economic criteria for using wetlands as nitrogen sinks under uncertainty

If the environmental damages that are caused by excessive nitrogen load to the sea depend on the timing of emissions, then monitoring the stochastic variation of emissions is crucial for controlling eutrophication damages. A significant problem of nonpoint source (NPS) nitrogen pollution is that emissions are stochastic and difficult to control. The main purpose of this paper is to examine under what criteria wetlands are economically rational to use for controlling stochastic NPS pollution. Three criteria are identified using a simplified stochastic watershed model. It is suggested that wetlands are economically rational to use, especially when monitoring the uncertainty of emissions is a part of the decision problem. The theoretical findings are illustrated with an example from southwestern Sweden.

Costs and benefits of restoring wetlands: two Swedish case studies

Abstract Costs and benefits of restoring wetlands for nonpoint source nitrogen pollution are calculated for two Swedish regions: the Stockholm archipelago and Gotland, an island in the Baltic Sea. Costs for reducing the load of nitrogen to the Stockholm archipelago by measures involving wetlands, agriculture, sewage treatment plants, and air emissions are calculated and compared. The results show that restoration of wetlands may be the least costly measure, SEK 20/kg nitrogen abatement as compared to the next cheapest measure, SEK 25/kg. The results from Gotland indicate that the benefits per unit of investment of restored wetlands may be three times as high as associated benefits of investment in sewage treatment plants. This difference in benefits is due to two factors: the joint production of several environmental services and the self-organizing feature.

Alternative nitrogen reduction policies in the Malar region, Sweden

Abstract The load of nitrogen to the Stockholm archipelago from the Malar region, a drainage basin located on the east coast of Sweden, must be reduced in order to decrease eutrophication. Costs for two alternative nitrogen policies are estimated: (i) current policy defined as total costs for reducing the nitrogen emission at each source by 50%, and (ii) an alternative policy defined as the minimum cost for reducing the load of nitrogen to the Stockholm archipelago by 50%. Results demonstrate that the cost of the first alternative greatly exceeds the cost for the second alternative. One important reason is that in the second alternative the functioning of the Malar lake ecosystem as a nitrogen sink is accounted for, which implies cost savings since less man-made reduction is required at the emission sources. Another factor is the identification of a new ecological technology—restoration of wetlands—a low cost measure for reducing the load of nitrogen.

Value of land as a pollutant sink for international waters

Abstract The purpose of this paper is to analyse and compare the values of a marginal change in the area of land as a pollutant sink under different decision-making contexts and objectives: international coordination versus national policies for pollutant reduction, and maximization of net benefits versus minimization of costs for pollutant reductions. The analytical results show that a coordinated policy between countries generates a higher value of a marginal change in the supply of land as a pollutant sink than an uncoordinated policy. It is also shown that the value is lower (higher) under the decision objective of maximizing net benefits when the efficient pollutant load is higher (lower) than the load target under the cost effectiveness approach. An application to the Baltic Sea drainage basin land as a nitrogen sink for the management of eutrophication reveals that the differences between values under different policy contexts and objectives can be quite large in magnitude.