Global and national environmental issues

Environmental issues are harmful effects of human activities on the air, water, land, climate and living things. Some are global (they cross national borders), while others are national/local.

Global environmental issues

1. Climate change and global warming – due to greenhouse gases from fossil fuels, deforestation and agriculture.
2. Ozone layer depletion – CFCs and halons thinned the ozone layer (Antarctic ozone hole); controlled by the Montreal Protocol (1987).
3. Air pollution – vehicles, industry, coal power; about 7 million premature deaths per year (WHO estimate).
4. Water pollution and scarcity – sewage, industrial and agricultural chemicals; over 2 billion people lack safely managed drinking water.
5. Deforestation – especially tropical forests (Amazon, Congo, Southeast Asia).
6. Loss of biodiversity – habitat loss, overexploitation, pollution, invasive species.
7. Land degradation and desertification – overgrazing, poor farming.
8. Acid rain – SO₂ and NOₓ from coal and vehicles.
9. Waste and plastic pollution – plastics in oceans, e-waste, hazardous waste.
10. Population growth and over-consumption – pressure on all resources.

Key environmental issues of Nepal

1. Deforestation and forest degradation – illegal logging, fuelwood use, encroachment and road building.
2. Soil erosion and landslides – fragile young mountains, steep slopes, haphazard rural roads cut by bulldozers.
3. Air pollution – Kathmandu Valley often has PM2.5 far above WHO limits; sources: vehicles, brick kilns, dust, waste burning, forest fires.
4. Water pollution – untreated sewage and industrial waste in rivers (Bagmati, Bishnumati); contaminated drinking water; arsenic in Terai groundwater.
5. Solid waste management – open dumping; the Sisdol/Bancharedanda landfill problem in Kathmandu.
6. Unplanned urbanisation – loss of open space and farmland, traffic, noise.
7. Climate change impacts – glacier melt, GLOF risk, erratic rainfall, floods and droughts, drying springs.
8. Loss of biodiversity – poaching, habitat loss, invasive species.
9. Riverbed mining – excessive sand and gravel extraction (e.g. Chure region).
10. Floods and disasters – Terai floods, landslides, earthquakes.

Nepal's issues are linked with global ones: climate change from global emissions melts Nepal's glaciers, so both national action and global cooperation are needed.