CO2

Vera Prescott: I hate trees. They suck up all the oxygen.
Brantley Foster: Actually, trees produce oxygen.
Vera Prescott: Who are you? Mr Wizard?
--The Secret of My Sucess

Central to the global warming thesis is that carbon dioxide (CO2) in some quantity undesirable. However, as Thomas Massie observes, global warming proponents have yet to make a compelling case as to precisely what level of CO2 is 'bad.'

Plants, including ones we eat and ones our animals eat, do better when CO2 levels increase and not as well when CO2 levels decrease. My colleagues never discuss this when talking about the optimum level of CO2 in the atmosphere. The media is even worse - they think it’s poison. https://t.co/zTfMQGo3EG

— Thomas Massie (@RepThomasMassie) January 2, 2019

These pages have discussed the robust nature of the planet, including the capacity of plants to absorb large quantities of CO2 from the atmosphere, and the positive effects from associated 'greening.'

Last month we noted that global warming theory is based on three premises. 1) that the earth's atmosphere is warming significantly, 2) that humans are responsible for any significant warming that is taking place, 3) that warming to the degree projected by theory is inherently bad.

Neglect in adequately explaining the proposed net negative effect of CO2, given the various positives, contributes to the overall theory's failure at this point.