This is the opening to a terrific story by Rex Dalton in Miller-McCune:
It seemed like such an elegant answer to an age-old mystery: the disappearance of what are arguably North America's first people. A speeding comet nearly 13,000 years ago was the culprit, the theory goes, spraying ice and rocks across the continent, killing the Clovis people and the mammoths they fed on, and plunging the region into a deep chill. The idea so captivated the public that three movies describing the catastrophe were produced. But now, four years after the purportedly supportive evidence was reported, a host of scientific authorities systematically have made the case that the comet theory is "bogus." Researchers from multiple scientific fields are calling the theory one of the most misguided ideas in the history of modern archaeology, which begs for an independent review so an accurate record is reflected in the literature.
(Real Climate was dubious several years ago.) In his piece, Dalton goes on to chronicle the hubris of the comet proponents and notes:
Such intransigence has been seen before in other cases of grand scientific claims. Sometimes those theories were based on data irregularities. Other times, the proponents succumbed to self-delusion. But typically, advocates become so invested in their ideas they can't publicly acknowledge error.
The controversy will perhaps resonate beyond rarified science circles "because it involves the politically sensitive issue of a climate shift," Dalton writes. He then turns to a famous climate expert:
"It does feed distrust in science," says Wallace Broecker, a geochemist at Columbia University and an international dean of climate research. "Those who don't believe in human-produced global warming grab onto it."
