Integrated environmental assessment needs to be firmly based on reliable technical data and information. Environmental progress and policy effectiveness can be assessed only if quality data are routinely collected through monitoring systems. However, environmental monitoring infrastructure is poorly developed in most countries, making regular production of policy-relevant environmental data and indicators impossible. The situation is being exacerbated by the decline of some existing monitoring systems due to shrinking resources.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities.
Agenda 21 recommends:
(a) environmental monitoring and assessment, both through improved participation by the UN system agencies in the Earthwatch programme and expanded relations with private scientific and non-governmental research institutes; and strengthening and making operational its early warning function;
(b) strengthening national, state/provincial and local assessment and ensuring cooperation/networking between existing environmental information and monitoring systems, such as Earthwatch and the Sahara and Sahel Observatory;
(c) supporting and concentrating UNEP capacity in this field.
Environmental assessments need data that are geo-referenced and information that is broken down by spatial areas other than administrative units. These data are still relatively scarce.
Assessment at regional and global scale requires the aggregation of data relating to smaller areas. Data can be aggregated only if they measure the same thing in the same way and with the same precision. Available data frequently do not measure up to these specifications.
Shortcomings make integrated, cross-sectoral global assessment and trend analysis always difficult and sometimes impossible.