Carbon dioxide is not poisonous, and it is not a pollutant. It is as necessary to plant life as oxygen is for us, and vital for all life on the planet.
Contrary to some advertising claims, the trees will not thank you for reducing CO2 output, any more than we would be thankful for reduced levels of oxygen.
When most modern trees and flowering plants evolved, levels of CO2 were as much as ten times higher than they are now. Most plants now struggle in what from their point of view is a seriously CO2 depleted atmosphere.
Lower carbon dioxide in the atmosphere means less green, not more. More CO2 means more green, more forests, more productive crops.
We are warned that increasing levels of CO2 will turn the seas acid and destroy coral reefs. Coral reefs evolved and thrived during the Mesozoic Period, when atmospheric CO2 levels stayed above 1,000 parts per million for 150 million years and exceeded 2,000 parts per million for several million years, compared with 380 ppm now.
There is no evidence of any correlation between changing CO2 rates and changing temperatures in the 20th Century. And historical records show changes in CO2 concentration follow changes in temperature, not the reverse.
For more detail, with graphs and pretty pictures, read my Introduction to Global Warming Science.
And more science, less politics, please, you EPA guys.