Absolutely, co2 in the atmosphere is as important to plants as oxygen is to us if co2 drops below 150 ppm the world would be a brown desert. According to all of the core sample data that has been compiled over many years the amount of co2 that was in the atmosphere in prehistoric times was between 1000 to 10,000 ppm, over the last few million years co2 levels have been gradually reducing down to a low point of 280ppm before the industrial revolution around the 1700s now co2 levels are around 420 ppm and the world is getting greener but the so called Greens want to cut emissions which would result in a browning of the globe not greening.
