While it is perhaps a stretch to say that one must be an environmentalist in order to be Gorean, it would not be a great stretch. As noted, the name of the Gorean homeworld is “Home Stone”, a reference to that which is the beating heart of a Gorean’s life.
The books also state, repeatedly, that Goreans love their world. Its “clean and untainted” air is oft contrasted with the “polluted” air of Earth. There is perhaps little to add to this particular line:
“Goreans care for their world. They love the sky, the plains, the sea, the rain in the summer, the snow in the winter. They will sometimes stand and watch clouds. The movement of grass in the wind is very beautiful to them. More than one Gorean poet has sung of the leaf of a Tur tree. I have known warriors who cared for the beauty of small flowers.”
Hunters of Gor, Page 119
A healthy respect for nature and its beauty, and an inclination to protect and preserve it, is a very Gorean trait.