I have a very incomplete understanding of the science of these impacts, but the idea that a large impact triggered the end of the last ice age makes sense to me. Triggering the Dryas seems a little out there, but you never know.
Global warming and cooling has a very set cycle, for a very specific set of reasons...nothing of which has to do with Al Gore, meteors, etc.
Look up "Milutin Milankovich", astrophysicist, at the NASA website. Read all about his research, and how over 50 years of collected data supports it.
And then laugh your ass off the next time someone starts fretting about this stuff or screaming about SUVs.