| Abbreviation | Definition |
|---|---|
| GHG | Greenhouse Gas |
| GIF | General Image Format |
| GIFA | Governing International Fisheries Agreement |
| GIN | Greenland-Iceland-Norway |
| GIOS | GOOS (Global Ocean Observing System) Integrated Observing System |
| GIPME | Global Investigation of Pollution in the Marine Environment |
| GIS | Geographic Information System |
| GISP | Greenland Ice-Sheet Project |
| GISS | Goddard Institute for Space Studies |
| GLA21 | Geophysics Luminous Aurora-like Phenomena: Auroras and Surface Fogs |
| GLAMIS | Grants and Loans Accounting and Management Information System |
| GLAS | Goddard Laboratory of Atmospheric Sciences |
| GLCFS | Great Lakes Coastal Forecasting System |
| GLERL | Great Lakes Environmental Research Laboratory |
| GLFC | Great Lakes Fisheries Commission |
| GLFS | Great Lakes Forecasting System |
| GLIN | Great Lakes Information Network |
| GLO | Glacial Lake Outburst |
| GLOBE | Global Backscatter Experiment |
| GLOBE | Global Learning and Observations to Benefit the Environment |