"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.
If you throw darts at a bullseye and are good at it, most will hit near thr bullseye and fewer and fewer will hit the farther away you get.
Scientists will often take their models and data and say, "okay how far off were we?" as if the model were the dart board and the data was one or more throws.
Standard deviation is a standardized measure of how far one is from the center of the distribution of "dart throws". For the very common bell curve (Gaussian distribution), it's a particular distance from the mean value.
In practical terms, they're saying they threw a dart and it ended up two blocks away. The model is wrong now - the world doesn't work like it used to and how it waa predicted to work.
Just to be clear, it's not 5 standard deviations off of modeled ice, it's 5 off of previously observed ice. I'm assuming at the cross section where the difference is deepest. Taking the time series from this year in total, it looks more like 3 or 4 sds off the mean
Ah, interesting. Both are bad in their own ways.