Climate change has been a fact for billions of years, CO2 is good for plants, therefore there is more green than ever

The issue with this statement is that there isn't more green than ever. Firstly, plants have multiple needs like other nutrients, water, and sunlight. Plants don't grow more and healthier because you give them a single nutrient like how any human wouldn't do well off a single nutrient. Secondly, deforestation is still a problem. Older and richer ecosystems like rainforests are capable of absorbing more carbon and putting it in the ground.

That's why it's so important to properly preserve our national parks (among other reasons), only cut down trees that are grown to be cut down - opposed to clearing old ecosystems, and preserve the high seas which provide about 50-80% of our oxygen