Earth Day was celebrated this weekend, and it’s probably not a stretch to say that most of you participated in some way, whether it was joining a local cleanup, planting trees, or just pledging to make better use of your reusable water bottle and grocery bags.

A 2010 study by Trucost estimated that environmental damage caused by humans is as high as 11 percent of global GDP. And as the global population grows—and grows richer—the potential for environmental damage is increasing. The good news is that many stakeholders—from solo entrepreneurs to global conglomerates—are working on projects to reverse, reduce, or eliminate this damage. And many are doing so with robotic technology.

In honor of Earth Day 2017, here are some of the most promising robot technologies that will help save the environment.