[Pox]

Of course they are, but when you have enough CO2 to displace most or all of the breathable air in a given area for a few minutes, what do you think is going to happen? See CO2 Suffocation or CO2 Poisoning. Not to mention Lake Nyos.

http://en.wikipedia.org/wiki/Lake_Nyos

[muir_redwoods]

I’m well aware of CO2’s ability to suffocate; the topic under discussion was CO. I think the government has lots easier ways to kill large numbers of people that CO2 suffocation.