| Abbreviation | Definition |
|---|---|
| NABERS | National Australian-Built Environment Rating System |
| NAD | Naturally Aspirated Deisel |
| NAEM | National Association for Environmental Management |
| NAEM | Netherlands Annual Ecology Meeting |
| NAEP | National Agency for Environmental Protection |
| NAFA | National Air Filtration Association |
| NAPA | National Adaptation Programme of Action |
| NAPCP | National Air Pollution Control Programme |
| NAPS | National Air Pollution Surveillance |
| NAPS | Nissan Anti Pollution System |
| NARCS | NPROVS Archive Statistics |
| NAS | National Accessible Scheme |
| NASF | National Association of State Foresters |
| NASSO | National Sample Survey Office |
| NATA | National Air Toxics Assessment |
| NBIC | National Ballast Information Clearinghouse |
| NBMCA | North Bay-Mattawa Conservation Authority [Ontario, Canada] |
| NC | Noise Criteria |
| NCAR | National Center for Atmospheric Research |
| NCAS | National Centre for Atmospheric Science |