My understanding is the duration does not really line up with an impact event also the starting periods don't seem to line up correctly. "In Western Europe and Greenland, the Younger Dryas is a well-defined synchronous cool period.[34] Cooling in the tropical North Atlantic may, however, have preceded it by a few hundred years; South America shows a less well-defined initiation but a sharp termination."

Which is what I find annoying about pet theories in books, you can make plenty of things seem convincing by leaving out other evidence.