AT ONE time, the Danish Society for the Conservation of Nature (Danmarks Naturfredningsforening -- DN) had more members than Denmark's political parties. Its large support base made DN the most powerful green NGO in Denmark, influencing decision-making at both the local and national levels. For example, an ambitious and costly plan to halve the organic pollution of Danish waters was adopted by parliament a few years ago on the basis of a scheme worked out by DN.

But success brings its share of woes. DN now has to cope with falling memberships (See box). And what does the organisation do after contributing to solving the most visible environmental problems?

Founded as a minor local organisation, DN's primary task was to lobby for a Danish law on nature conservation. Such a law was passed in 1917 and gave DN the unique right to propose areas to be preserved. DN gained momentum from this success and grew to a national organisation with about 10,000 members.

Until the '60s, DN was a "decent" and "respectable" organisation, concentrating on conservation and maintaining a stable number of members. But with rapid urban growth, industrialisation and environmental degradation, DN adopted a more aggressive line.

In 1978, DN upgraded its media and information policy on environmental issues and initiated an all-out campaign to attract more members. It was decided to simply phone all Danes who weren't members and ask them to join. The result was astonishing: between 1978 and 1989, DN's memberships expanded from about 50,000 to 270,000, which was more than 5 per cent of the Danish population.

The expansion gave DN greater financial resources and a growing staff. Today, DN has 219 local chapters, which organise members at local levels, and a staff of 30 at its Copenhagen head office. It also draws upon nearly 60 scientific experts who participate voluntarily in various advisory committees.

DN's decision-making follows the traditional, hierarchical pattern. Local boards are elected for three years and each board is represented in the national council, where scientists and individuals with special commitment also have seats. The council meets twice a year to discuss and confirm political strategy, work programmes and the budget, as proposed by DN's executive committee.

DN can hardly be called a grassroots movement because the actual influence and participation of its members are quite limited. In spite of this -- or maybe because of it -- DN plays a very dynamic role and maintains a very high profile. DN and a few other groups are empowered to comment on proposed regulations and appeal decisions, including environmental permits. DN reviews about 4,000 permits annually and appeals about 2 per cent of them. Half the appeals bring about decisions that are more favourable to the environment. Along with its continuous review work, DN engages in local, national and international debates on environmental protection.

After initially dealing only with the preservation of the Danish landscape, DN today campaigns for renewable energy, clean technology, better public transport, use of green taxes and organic farming, among other things. Its means are not direct action, demonstrations or collection of signatures, but writing critical reports, supplying background information and direct lobbying.

Had DN embarked on a more radical and aggressive course, it would surely have evoked negative reactions from its members. Balance is the key word for an organisation that wishes to maintain at least one member in every eight families.

Partly due to its work and that of other influential green NGOs, Denmark's air pollution is declining rapidly and emissions of harmful elements are shrinking. The percentage of recycled water is increasing and overall energy consumption has almost been stabilised.