| Abbreviation | Definition |
|---|---|
| ACA | African Climate Alliance |
| ACACIA | Arid Climate Adaptation and Cultural Innovation in Africa |
| ACASA | Atlantic Climate Adaptation Solutions Association |
| ACC | Automatic Climate Control |
| ACCTS | Agreement on Climate Change Trade and Sustainability |
| ACDC | Advanced Climate Dynamics Courses |
| ACFP | Australian Climate Finance Partnership |
| ACIS | Applied Climate Information System |
| ACME | Accelerated Climate Model for Energy |
| ACME | Accelerated Climate Modeling for Energy |
| ACPC | Aerosols Clouds Precipitation and Climate |
| ACRII | Accelerating Climate Resilient Infrastructure Investment |
| ACSIS | Atlantic Climate System Integrated Study |
| ACT25 | Allied Climate Transformation (COP 25) |
| ADVICE | Annual to Decadal Variability In Climate in Europe |
| AECM | Agri Environment Climate Measure |
| AFN | Action For Nature |
| AGCC | Action for a Global Climate Community |
| AGCC | Anthropogenic Global Climate Change |
| AL | Action Levels |