Restore the Earth, Day!
When one thinks about environmentalism they are probably thinking about conservation. Actively protecting beautiful, natural places. Or maybe one thinks of waste reduction and recycling. Or maybe planting trees. Which are all needed and wonderful actions. What I am personally interested in is a practice called Ecological Restoration. It is the science and art of trying to rebuild ecosystems on land damaged by human action.
In the process you remove what you can from human activity, get rid of invasive plants, and plant a large diversity of grasses, flowers, trees, that would have been there before the land was altered. To try to restore wildlife habitat.
I think restoration is beautiful and poetic environmental work. Most of us can't create a national park or protect untouched wilderness. But anyone can make the little bit of ground they have access to better for wildlife by planting native plants. Doing that creates habitat for wildlife. Helps the soil hold water, sequesters carbon, and it's beautiful. It is something I am trying to make a bigger part of my time on Earth. I think if a place can be wild that it should be wild.
One can restore their yard to be wild, spread native wildflower seeds in an empty lot, or volunteer with restoration projects in your town. We can undo some of the damage humanity has done and make the world a more vibrant and healthy place.
My side yard where I removed the lawn and am planting local grasses and wildflowers.