"For those of you who are interested in statistics, this is a five-sigma event. So it's five standard deviations beyond the mean. Which means that if nothing had changed, we'd expect to see a winter like this about once every 7.5 million years.
[...]
She fears a further change in the balance could trigger a tipping point from where it's difficult to reverse the trajectory. "We might end up in a new state," she said. "That would be quite concerning to the sustainability of human conditions on Earth, I suspect.
I think part of the problem is that the chain of societies we've built is plain too complex for anyone to really keep under control or even effectively coordinate, too. Even by the people who think they grasp enough of it to get a rein on it. At scale, a lot of systems take on lives of their own.