So what does CO₂ really do to Nature?

What you are about to see is a time-lapse video of two plants growing side-by-side, but under the influence of different concentrations of carbon dioxide.

Original source

What they told you in biology class is real — carbon dioxide is food for plants.  You need this food for plants in order to survive, because the moss basic life forms need plants, and you need them.  Humans reintroducing carbon dioxide in the atmosphere — a carbon that was fixated underground for very long — while only a small contribution, has improved this life cycle of Nature, rather than harming it in any way.

There are self-serving, perverse people who want to convince you that you should hate yourself for depending on carbon.  Don't let them fool you with lies.