I think your teacher scares me. He represents the heart of what has gone wrong with people's perceptions of the environment. He negates the necessity of interlocking components to create a stable ecology needed for survival. If we step back, we can see an enormous web relating to how things connect.
The mentality seems to be, if we remove one thing another will take its place or the planet will adapt. We keep on with that assumption, continuing to eradicate plants and animals without thought of consequence.
E.g., we are losing untold cures locked within rainforest plants through deforestation and the elimination of animals necessary to continue the growth cycles of those plants. We are destroying the world at a much faster rate than we are understanding it.
Our evolution is a strange cycle of devolving. When humans came into being there is one absolute truth - we had to understand the environment in order to survive. The growth of industry has devolved that core knowledge. Many view nature and animals as optional, which is a thought process furthest from accurate.
Check out Wikipedia Tree page
. The best thing any of us can do is ask the hard questions, seek reliable answers, and formulate informed perspectives grounded in common sense.A dead planet is not an inevitability - it is a self-fulfilling prophecy within our control.