This is what it looks like:
Although the origin of these YDB markers remains speculative, any viable hypothesis must account for coeval abundance peaks in NDs, magnetic impact spherules, CSps, and charcoal in Lake Cuitzeo, along with apparently synchronous peaks at other sites, spanning a wide area of Earth’s surface. Multiple hypotheses have been proposed to explain these YDB peaks in markers, and all but one can be rejected. For example, the magnetic impact spherules and NDs cannot result from the influx of cosmic material or from any known regular terrestrial mechanism, including wildfires, volcanism, anthropogenesis, or alternatively, misidentification of proxies. Currently, only one known event, a cosmic impact, can explain the diverse, widely distributed assemblage of proxies. In the entire geologic record, there are only two known continent-wide layers with abundance peaks in NDs, impact spherules, CSps, and aciniform soot, and those are the KPg impact boundary at 65 Ma and the YDB boundary at 12.9 ka.
And note, this, like volcanic events, isn’t the sort of thing amenable to modeling.
Yep, more evidence of the need for planetary defense.
There is one HUGE issue if the Younger Dryas was of extraterrestrial origins and not part of the ned of the last glacial period; it pushes back the start of the current interglacial (the Holocene) by close to two thousand years. Glacials and interglacials are cyclic, so this should be a major concern; we may be far closer to the next glacial epoch than we think.
It’s also worth noting that the last interglacial, the Eemian, which occurred from about 128,000 BC to 112,000 BC, was far warmer than our current times; they had hippopotamus in the Thames river in what’s now the UK, sea levels were about 26 feet higher than today, and the seas were warmer. (and not an SUV in sight!).
What galls me is that, even if the anthropogenic warmists were right, a new glacial era would be FAR worse than the “global warming” they so fear. It would (via climate impact on agricultural production) cost billions of lives. (the ice sheets take millenia to grow, but the temperature shift that causes them tends to happen quickly, the shift from interglacial to glacial taking as little as four years in one case).
The grand irony is that if human activity is indeed warming the planet to some degree, that may be the only thing keeping us from a new glacial era, which would be by far the greatest disaster in human history (and last for a thousand centuries (about twice as long as the human race has existed).