Environmental Studies
- neutrality theory of evolution
- New Zealand floral region
- Newer Drift
- Nitrification
- nodum
- nomogenesis
- non-frontal depression
- nonsense mutation
- normal analysis
- North American lowland coniferous forest
- North Atlantic deep water
- north-east African highland-and-steppe floral region
- Notogea
- NOx (Nitrogen Oxides)
- nuchal
- nuclide
- Nukumaruan
- null point
- numerical method
- nutrient cycle