Here is another robot that can help save the environment. Romu is a sheet pile driving robot that autonomously builds erosion barriers from interlocking metal sheet in natural terrain. These machines can be used to protect threatened areas.
The idea is to use robots like this for sustainable land management. Romu leverages its own weight to drive sheet piles into the ground. It has 4 wheels coupled to a separate linear actuator. The above video shows it in action.