| Event | Year |
| EPA reports that greenhouse gas buildup will lead to global warming | |
| Yellowstone National Park established | |
| Silent Spring by Rachel Carson published | |
| World Wildlife Fund founded | |
| Garrett Hardin publishes Tradgedy of the Commons | |
| Clean Water Act passed | |
| The first Earth Day | |
| Exxon Valdez oil spill | |
| Nature Conservancy formed | |
| Clean Air Act passed | |