I'm going to start with; this question is asking your opinion, so this answer may or may not work for you. Therefore, I am going to try to add several answer options.
What is your opinion on environmental art?: Answers will vary, I cannot help you on this question.
Do you consider it art?: YES or NO.
What about the trans-species art you read about?: sadly, I cannot help you with this one either, as I don't know what you read.
Do you think eco-art will gain popularity due to the recent interest in the environment?: (answers will vary. My answer would be:) Yes, I think it will gain popularity. The recent interest in the environment will encourage people to make more eco-art, and therefore it will most likely become more popular.
Sorry I could not answer a few of the questions. Hope this helps!