APPENDIX I

The Pressure-State-Response concept

The OECD and several countries base their work on indicators on the Pressure-State-Response concept. In terms of sustainable development, human activities exert pressures on the environment, which lead to changes in the state of stocks or quality of resources, which lead to responses of society through, for instance, environmental, economic and sectoral policies, which may be aimed at adapting to the changes in state or relieving the pressures. This framework helps to clarify thinking, but it often needs to be modified to suit the purposes of different exercises. Thus, the Working Group defining Indicators of Sustainable Development for the United Kingdom (DETR, 1996) abandoned the Pressure-State-Response concept and separated out indicators concerned with the economy (transport, energy etc.) the environment (air, water etc.) and the actors involved (enterprises, households etc.).

The Pressure-State-Response model might be a useful framework for thinking about a comprehensive set of indicators covering all aspects of climate change using the following definitions:
C pressures: activities which lead to the emission of greenhouse gases (transport, industrial activity, heating, agricultural practices etc.), rates of UK greenhouse gas emissions as a result of those activities (CO2, CH4 etc.) and concentrations of greenhouse gases in the atmosphere;
C states: the climate of the UK (temperature, rainfall etc.), its variability and change, climatic changes occurring regionally which affect the UK (eg in the North Atlantic) and sea level rise;
C states and responses: river flows, soil moisture and other changes in hydrology which occur in response to changes in climate but also represent states (conditions) affecting the natural environment and socio-economic activities.
C responses: the impacts of changes in climate and hydrology on the natural environment, human affairs and socio-economic activities and adaptation to these impacts.

Within the above framework, this study assumed that all the indicators representing pressures leading to climate change are already documented in UK reports submitted under the Framework Convention on Climate Change (Anon, 1994, 1997) and more comprehensively by Salway (1996). We do not, therefore, report greenhouse gas emissions or atmospheric concentrations, nor indeed indicators of any of the measures that may be taken to mitigate emissions, such as the use of more fuel-efficient cars or forest planting.

This report does, however, cover the state variables, including those related to hydrology, as well as the response variables, including both the direct response of plants, animals and humans to the weather (eg the timing of spring events, potato yields and the seasonal pattern of human mortality) the human response to warmer or drier weather (eg consumption of gas, use of irrigation water and tourist activity) and some economic impacts (eg insurance claims and activity in the skiing industry).