Not much point in talking to you if you're going to base your arguments on demonstrably false claims.
Earth's five mass extinction events
And if you don't feel up to reading that whole thing, here's the key paragraph:
What Veron 2008 found was each mass extinction event corresponded to periods of quickly changing atmospheric CO2. When CO2 changes slowly, the gradual increase allows mixing and buffering of surface layers by deep ocean sinks. Marine organisms also have time to adapt to the new environmental conditions. However, when CO2 increases abruptly, the acidification effects are intensified in shallow waters owing to a lack of mixing. It also gives marine life little time to adapt.
You appear to be arguing that because carbon dioxide is only a trace constituent of the atmosphere it can't possibly have the large effects claimed for it, which betrays a fundamental ignorance of the science. You can't base any sensible argument on that kind of reasoning. Trace constituents can have huge effects in many circumstances. Your body, for instance, is about 1 part per million iodine, much less than CO2 is of the atmosphere, but without it you'd be devastatingly ill and soon dead.