Aside from protests by Al Gore, Leonardo Di Caprio and friends, the public didn't seem to raise its CO2 anguish much above the Russians-election frenzy when Trump exited the Paris Climate Accords.
Statistician Bjorn Lomborg had already pointed out that the Paris CO2 emission promises would cost $100 trillion dollars that no one has, and make only a 0.05 degree difference in Earth's 2100 AD temperature. Others say perhaps a 0.2 degree C (0.3 degrees F) difference, and even that would hold only in the highly unlikely event that all parties actually kept their voluntary pledges.
What few realize, however, is that during the last Ice Age too little CO2 in the air almost eradicated mankind. That's when much-colder water in oceans (that were 400 feet shallower than today) sucked most of the carbon dioxide from the air; half of North America, Europe and Asia were buried under mile-high glaciers that obliterated everything in their paths; and bitterly cold temperatures further retarded plant growth.