If we are to achieve sustainable patterns of economic and social development, and therefore meet the goals set by both the UK’s Strategy for Sustainable Development and agreements made at the European scale following the Göteborg Summit in 2001, then those concerned with the development and appraisal of policy must understand of the constraints imposed in decisions by the environment. To do this we must know the thresholds or limits beyond which the integrity of environmental systems will be damaged by people’s activities.
Unfortunately the identification of environmental thresholds or limits is a complex task, because the work cuts across a range of topic areas, and includes consideration of biophysical, social and economic factors. For example, in the context of understanding limits as they apply to water quality the EU argue that an environmental sustainability threshold must be seen “as a physical value reflecting the extreme state of the environment and as an economic value reflecting the damage on monetary valuation or the restoration costs”. Thus if we are to apply this approach in the UK, we would need to understand not only the biophysical constrains that control water quality, but also understand social and economic factors that determine attitude to risk and protection costs. The complexity of defining such limits is compounded by the fact that a number of different types of change in system behaviour can occur when a limit is exceeded, and that the consequences of such a ‘regime shift’ may vary from place to place and over time.
The tools needed by policy customers to understand the way in which environmental thresholds or limits are determined are unevenly developed across all topic areas included in Defras remit. These include biodiversity; water quality, supply and demand; the marine environment; the soil environment; land-use; landscapes; air quality; green house gas emissions; recreation and access to the natural environment; rates of climate change; emissions and ozone depleting substances; levels of dispersal of toxic substances and the disposal of solid waste; sustainable use of renewable resources and the appropriate rate of use of non-renewable resources.
This project will provide an overview of the current state-of-the-art’ in each of these areas, based on a set of review material generated by experts in the different fields, so that the policy advisors in the UK can be informed about:
The ways in which environmental thresholds or limits are defined using scientific and social criteria;
The robustness of the evidence base that is available to them when dealing with threshold issues in a
policy context; and,
The gaps in existing knowledge and the extent to which these might be overcome by further work.
Current understandings in the literature suggest that in the context of sustainability planning, three distinct sustainability threshold criteria can be identified for any ecosystem good or service: the biophysical, the economic and the actual. The biophysical threshold can be estimated on the basis of environmental studies of system behaviour and modelling. To estimate the economic threshold requires valuing the ecosystem good or service and the externalities experienced by different stakeholders if the threshold is exceeded. The actual threshold at which political action is taken depends on the relative power of different stakeholder groups to influence policy makers and the externalities they experience when the threshold is exceeded. While the set of thresholds for any ecosystem good or service will vary with economic, social and environmental conditions, it is expected that by empirical study of thresholds in different conditions it will be possible to determine generic rules to identify common sustainability thresholds. The extent to which this is possible across the topic areas included in Defra’s policy portfolio will be determined by this study.
The study will deliver an understanding of the tools and concepts needed to apply thresholds of sustainability, and a suite of bibliographic and conceptual databases that can be used to support future applied work in this area. Throughout the quality of the work will be tested by independent review, and ultimately by publication of the results in the international, peer-reviewed literature.