Tales of the Black Swan

Children's stories are cautionary tales that help to relay messages of right and wrong, good and bad, and somehow our hero always pulls through.

Yesterday in a presentation at our Balaton Group Meeting by Dick Barber, a Duke University oceanographer known for his work on El Nino, we heard a story about black swans, which for me was the ultimate cautionary tale. The Black Swan, a theory made popular again recently by Nassim Nicholas Taleb in his book by the same name, is a large-impact, hard-to-predict, and rare event beyond the realm of normal expectations. Black Swan was adopted as a metaphor for this phenomena because in the 17th century the Europeans, who felt they knew everything about swans, including that they were white, were astounded to find a black swan in Australia. Their science had not predicted that and there was no way it could have.

Dick Barber invoked the Black Swan concept in his talk about our oceans' response to climate change and our global climate regime. Our climate regime sits in a narrow band of plus/minus 18 degrees and has stayed there for 4 million years (Dick said that this fact shakes his faith in atheism). The group asked him if climate change could cause this regime to shift or flip. Because our models are built with historical information, they simply cannot predict these events; they are "new under the sun". Dick said that there might be two examples of climate regime shift/flip, Mars which froze and Venus which evaporated. Neither is a very cheery story.

Could our earth's climate regime flip? We simply do not know, our models have no way to tell us. If the black swan is a cautionary tale, does our hero pull through in the end?