I think the nuance is important here. If CO2 was toxic we would have handled it already. Obviously CO2 is an asphyxiant, but so is nitrogen and that's 70% of ou

I think the nuance is important here. If CO2 was toxic we would have handled it already. Obviously CO2 is an asphyxiant, but so is nitrogen and that's 70% of our atmosphere. No one complains about atmospheric nitrogen. Our bodies handle CO2 continuously as a product of metabolism. I view CO2 like I view processed sugar - if you have an energy deficit or energy balance, it's probably fine in small amounts; if you have a surplus, it's not ok. I've been thinking about the industrial miracles of the 19th and 20th century. Steel, Aluminum, Concrete, Gasoline, Natural Gas, Plastic, Glass, Integrated Circuits, Artificial Fertilizers, Air Conditioning, Automobiles. If you only look at the positive side, all of these are truly miraculous - they've provided humanity with incredible increases in productivity and happiness. They've let people live longer and in less hospitable places. They've supported a higher population level than people expected was possible. But those miracles have terrible side effects. I won't list them, it's too depressing.