Nepal is a land of extreme contrasts in climate and geography. It has a unique topography ranging from lowlands with sub-tropical jungles to arctic conditions in the Himalayan highlands. Within a mere 150 kilometers the land rises from near sea level in the south to over 8000 meters in the north. This, together with the monsoon rainfall along the south facing slopes, has resulted in compacting virtually all climate zones found on planet Earth. As a result, Nepal has been endowed with a great diversity of life-zones providing a home for a large variety of plants, birds and animals.
- Air and water pollution are significant environmental problems in Nepal. Roughly one-third of the nation's city inhabitants and two-thirds of all rural dwellers do not have pure water and the use of contaminated drinking water creates a health hazard. Untreated sewage, agricultural runoff, and sedimentation and discharge of industrial effluents are prominent sources of pollution.
- The burning of wood for fuel is a significant source of indoor air pollution and respiratory problems. Vehicular and industrial emissions increasingly have contributed to air pollution in urban areas.
- Deforestation affects a great proportion of the population and has the worst consequences for economic growth and individuals’ livelihoods. Forest loss has contributed to floods, soil erosion, and stagnant agricultural output. Estimates suggest that from 1966 to 2000 forest cover declined from 45 to 29% of the total land area. Often cited causes of deforestation include population growth, high fuel wood consumption, infrastructure projects, and conversion of forests into grazing- and cropland. According to government estimates, 1.5 million tons of soil nutrients are lost annually.
- Land degradation is attributed to population growth, improper use of agro-chemicals, and overly intensive use of landholdings that are too small to provide most households with sufficient food. Government policies have attempted to address these numerous and related problems, but policies often are hampered by lack of funding, insufficient understanding of Nepal’s mountain ecosystems, bureaucratic inefficiency, and sometimes contentious relations between the central government and local communities.
- UNEP has warned that more than 40 Himalayan glacial lakes are dangerously close to bursting because of the ice melt caused by global warming. Rapidly melting glaciers means more seasonal variation in river flow, which will in turn result in more floods and draughts in the country. This will also result in more Glacier Lake Outburst Floods, which can be disastrous to communities and infrastructure along the rivers. Other impacts of climate change can be reduced agriculture production, loss of biodiversity, increased desertification and changes in social structure.