That being said, the more important question is whether or not we would actually terraform if we knew it could harm other life forms. I really do believe that we wouldn’t. I think that as humans we feel a guilt over what we have done to our own planet which would stop us from destroying another life form. We all know that our species has developed civilization in such a way that we now have an uncontrollable and irreversible pattern of poisoning of destroying our own earth. We destroy our own forests to expand our domain, destroying ecosystems and driving entire species into extinction in the process. We are seeing and hearing the effects of this habit of ours every day, and it bothers us. We know we are terrible to our world, and we wish we could change it, but we can’t. Because of this guilt, I do believe that we would refrain from terraforming if it threatened the existence of another life form. This hypothesis, however, is conditional on the threat to human existence. If the human species is in danger of becoming extinct, then all bets are off. Because our will to survive as individuals and as a species is so strong, we would absolutely destroy another life form if it was a situation of life or death for us. Let’s hope it never comes to that.