[nlitened]

Plants stop being able to do photosynthesis efficiently at lower CO2 ppm values (plants need CO2), which lead to massive deforestation. Thanks to current 400+ ppm values, in many places of the world the greenery returned in the past decades. Values in 600—800 ppm range would be optimal for keeping our planet green and ecology.

[burnt-resistor]

Don't even start with Cato Institute pseudoscience climate denialism talking points.

[nlitened]

I don't know what Cato Institute is and what their talking points are, but you can look up photosynthesis details on Wikipedia or any other place you like.