| Abbreviation | Definition |
|---|---|
| IEG | Institute for Environmental Genomics |
| IEH | Integrated Environmental Humanities |
| IEHG | International Environmental History Group |
| IEHO | Independent Environmental Health Officer |
| IEI | Idiopathic Environmental Intolerance |
| IELA | Irish Environmental Law Association |
| IEM | Integrated Environmental Management |
| IEM | Iowa Environmental Mesonet |
| IEMA | Illinois Environmental Management Association |
| IEMS | Integrated Environmental Media System |
| IEMS | International Environmental and Marine Services |
| IEMS | intranet Environmental Management System |
| IEN | Indigenous Environmental Network |
| IEN | Institute for Environmental Negotiation |
| IEN | Irish Environmental Network |
| IEO | Installation Environmental Office |
| IEPA | Illinois Environmental Protection Agency |
| IEPA | Independent Energy Producers Association |
| IEPA | Irish Environmental Protection Agency |
| IEPHRO | International Environment Protection Human Rights Organization |