About 10 per cent of the world's population live in the mountains, while 40 per cent occupy the watershed areas below them. Thus, half of the world's people depend directly or indirectly on the mountains. Mountains provide water, energy, minerals, and forest and agricultural products and are areas of recreation. They also store the biological diversity necessary for the sustainability of human life. Mountain environments are essential to the survival of global ecosystems.
Mountain ecosystems are also fragile.
They are susceptible to soil erosion, landslides, and loss of genetic diversity. Physical isolation has excluded the mountains and their populations from development, resulting in political and economic marginality. Mountain people suffer from unemployment, poverty, poor health, and insufficient sanitation. In contrast to popular perceptions, however, some mountain areas have not only improved their economies radically, but they have also preserved their environments, biodiversity, and cultural heritage. It is essential to learn from successes as well as from failures.