also, i don't necessarily mean to endorse this worldview in terms of its potential impact on policy, though there may be some truth to it, technically speaking.
co2 is problematic because of concentration - the sheer volume.
leaded gas and mercury are a problem because of bio-concentration.
dilution still helps!
when people suffocate in the fire from CO2 - that's concentration
and dilution helps people to not literally die from that
global warming due to CO2 levels everywhere is entirely different problem. (and if we could dilute CO2 into the space, it would also be solved, lol)
This is just not true, and you seem to agree with that.
Yes, CO2 is problematic because of the sheer volume. The sheer volume means that dilution does not solve the problem.
Leaded gas and mercury are a problem because of bio-concentration. Which means that dilution does not solve the problem.