| Term | Report | | Abundance | GEO-7, GEO-1-6 |
| Acceleration | GEO-7 |
| Acidification | GEO-7, GEO-1-6 |
| Acidity | GEO-7, GEO-1-6 |
| Actions | GEO-7 |
| Actions and policies | GEO-7 |
| Actors | GEO-7 |
| Adaptation | GEO-7, GEO-1-6 |
| Adaptive governance | GEO-7, GEO-1-6 |
| Aeroponics | GEO-7, GEO-1-6 |
| Afforestation | GEO-7, GEO-1-6 |
| Agenda 21 | GEO-7, GEO-1-6 |
| Agricultural landscape | GEO-7, GEO-1-6 |
| Agrivoltaics | GEO-7 |
| Agroecology | GEO-7, GEO-1-6 |
| Agroecosystems | GEO-7, GEO-1-6 |
| Agroforestry | GEO-7, GEO-1-6 |
| Algal bloom | GEO-7, GEO-1-6 |
| Alien species | GEO-1-6 |
| Alternative proteins | GEO-7 |
| Anthropocene | GEO-7, GEO-1-6 |
| Anthropogenic | GEO-7, GEO-1-6 |
| Anthropogenic emissions | GEO-7, GEO-1-6 |
| Antimicrobial resistance | GEO-7, GEO-1-6 |
| Aquatic ecosystem | GEO-7, GEO-1-6 |
| Aquatic species | GEO-7 |
| Aquifer | GEO-7, GEO-1-6 |
| Arable land | GEO-7, GEO-1-6 |
| Artefacts | GEO-7, GEO-1-6 |
| Artisanal | GEO-7 |
| Availability | GEO-7 |