Assessing Future Risks to Ecosystems. K. L. Dickson, Institute of Applied Sciences, North Texas State University, Denton, TX; and S. Sanzone, Science Advisory Board, Washington, DC
As part of an Environmental Futures Project of EPA's Science Advisory Board, a process was explored for identifying and assessing risks to ecosystems in the 30+ year time frame. The principles developed in the SAB report "Reducing Risk" and the Framework for Ecological Risk Assessment (EPA/630/R-92/001) were used to develop a conceptual model for futures analysis. The conceptual model provides a methodology for identifying the interactions between drivers (ultimate causes of change), stressors, and ecological endpoints, delineating the causes and effects of environmental changes and the opportunities for management actions to reduce environmental risks. The first step in the process is to define primary drivers that determine trends in resource use, environmental stressors, and ecological endpoints which can be used to measure the effects of changes and stressors. Scenarios were developed to evaluate the significance of stressors under particular conditions in the future. The interaction between drivers and stressors was summarized in a matrix. The assessment endpoints were used to evaluate the interaction. The framework is most useful not for predicting the future, but in assisting decision makers to consider the impact of various possible scenarios and identify "no regrets" actions which avoid or minimize risks to ecosystems under a wide range of scenarios. The exercise confirmed that national environmental risks are dominated by large scale and long term issues, such as habitat alteration.