ENVIRONMENTAL MONITORING

The repeated collection of environmental data to understand environmental change and inform decision-making. Environmental monitoring is carried out by the United Nations, intergovernmental, governmental, non-governmental, academic and commercial organisations. It has gained worldwide importance through international environmental conferences like the Earth Summit in Rio de Janeiro in 1992 and in Kyoto in 1997. An example is the monitoring of the global carbon balance, especially absorption and release of carbon dioxide, which has been given a high priority by the United Nations Framework Convention on Climate Change (see convention). greenhouse gases and climatic change, ozone depletion, air pollution, soil degradation and water resources, tropical deforestation, desertification and biodiversity loss are major areas of concern. Each of these phenomena is affected by processes on local and global scales. To describe, understand, predict and mitigate these harmful processes, repeated measurements on large scales are needed. The central importance of environmental monitoring arises from its function as a key step in the iterative process of decision-making. Given the goal of sustainable development, it is crucial to continuously review the effects of economic and political decisions on the environment in order to assess their impacts.

Techniques for continuous monitoring and prediction of environmental key variables (environmentalindicators) have been developed. On national, continental and global scales, remote sensing plays a major role in delivering environmental data. In the past, remote-sensing data were collected on coarse spatial resolution, but advances in remote-sensing techniques have made it possible to operationally acquire data on continental scales with improved spatial and [Page 360]spectral resolution. Optical and microwave sensors are delivering complementary information on global processes. The European initiative on Global Monitoring for Environment and Security (GMES) aims at an operational earth observation (EO) system comprising optical remote-sensing instruments and radarremote-sensing instruments. Its objective is to provide operational long-term environmental data from space, air and ground observation systems. GMES has four components: (1) the space component (Earth Observation satellites, including the esa Sentinels and Contributing Missions); (2) in-situ ground-based and airborne networks; (3) data harmonisation and standardisation and (4) information services to users.

For monitoring pollutants in the environment on small scales, repeated assessments of bio-indicators can be used as an alternative to analytical chemistry. To assess the potential impacts of human activities on the environment, an environmental impact assessment (EIA) can be carried out. simulation models play an important role in predicting likely changes of environmental key variables. Different scenarios of complex environmental systems can be simulated by using different model parameters as input. Models may be used for temporal and spatial interpolation and extrapolation of environmental measurements.

[See alsoecotoxicology, environmental management, environmental policy, global earth observation system of systems (geoss), temporal change detection]