We seem to have had a spate of papers favourable to the idea of a Yonger Dryas boundary event that involved bombardment by meteors or comet fragments – see the latest offering at http://cosmictusk.com/first-harvard-now-dartmouth-evidence-identified-fo… … where a paper published by PNAS, once again, is available to download or read online. It is 19 pages of pdf in length. PNAS is the US equivalent of the Royal Society.
At http://phys.org/print297340514.html … we have the same story but from the angle of climate change and the killing off of herds of animals and their predators, most famously the mammoths and the sabre toothed tigers. The consensus view is that an ice dam in NE North America was ruptured and a large quantity of fresh water spilled out into the North Atlantic and shut down the ocean currents. These are fomed from tropical water with an origin in warmer climes such as the Caribbean or the Indian Ocean. It is assumed a collision of these tropical currents with an inflow of cold fresh water (as opposed to the salty ocean water) was enough to put a brake on the ocean currents moving up and down the Atlantic basin. The paroblem with this theory, and with the new one, is that the Younger Dryas cooling lasted 1300 years (on the geo-chronological and uniformitarian time-scale). Hence, not all scientists are going to buy into the cosmic explanation – just as not all scientists were convinced by the ocean current explanation.