An alarming heatwave in the sunless winter Arctic is causing blizzards in Europe and forcing scientists to reconsider even their most pessimistic forecasts of climate change.The north pole gets no sunlight until March, but an influx of warm air has pushed temperatures in Siberia up by as much as 35C above historical averages this month. Greenland has already experienced 61 hours above freezing in 2018 - more than three times as many hours as in any previous year.
Seasoned observers have described what is happening as "crazy," "weird," and "simply shocking".
"This is an anomaly among anomalies. It is far enough outside the historical range that it is worrying -- it is a suggestion that there are further surprises in store as we continue to poke the angry beast that is our climate," said Michael Mann, director of the Earth System Science Center at Pennsylvania State University. [...]
But the heat peaks are becoming more frequent and lasting longer -- never more so than this year. "In 50 years of Arctic reconstructions, the current warming event is both the most intense and one of the longest-lived warming events ever observed during winter," said Robert Rohde, lead scientist of Berkeley Earth, a non-profit organisation dedicated to climate science. [...]
"This is too short-term an excursion to say whether or not it changes the overall projections for Arctic warming," says Mann. "But it suggests that we may be underestimating the tendency for short-term extreme warming events in the Arctic. And those initial warming events can trigger even greater warming because of the 'feedback loops' associated with the melting of ice and the potential release of methane (a very strong greenhouse gas)."
Previously, previously, previously, previously, previously, previously, previously, previously, previously, previously, previously, previously.
[Disclaimer: I work on climate change but only in the 'configure and run models' sense.]
I suspect that this is just an anomaly: I don't think there's any really good evidence that climate can suddenly, on timescales of a year or a few years, fall off a cliff and flip into some new state without some huge external forcing (such as a big meteorite). In fact there's evidence that this does not happen very often, which is that things (trees for instance) which depend on the climate changing only rather slowly over evolutionary timescales exist.
However the rate of change is already extremely high (we have no good data from times its been this high in the past: it probably was much higher in the event which killed the dinosaurs but that's too long ago for good data, and it's something like 10 times as high as it was during deglaciations where we do have decent data) and, obviously, is being driven by what is essentially a fairly large external forcing (humans) so it's dangerous to draw conclusions either way.
So it's likely an anomaly. This doesn't mean we're not fucked or that the arctic will recover: there's no real question that the arctic ice will be gone in less than fifty years, and we are definitely fucked. Just not this year.
(There will probably also be huge external forcings in due course: presumably when harvests start failing in the US the result will be a nuclear war as the survivors try to take over somewhere food will still grow.)
The closest analogy I've read about is the Paleocene-Eocene Thermal Maximum).
That was a period of carbon injection lasting about 20000 years, with the average carbon release being 0.2 gigatons per year. This resulted in a 5-8 degree Centigrade temperature excursion worldwide, which lasted about 200000 years.
Humans currently release about 10 gigatons per year, and are still ramping it up. We've already released about 8% of the total carbon released in the PETM, and we're picking up speed.
Even back in 1900, our fossil fuel emissions were several times the 0.2 gigaton rate of the PETM. So think about that, even if we cut our fossil fuel consumption to 19th century levels, even if we NEVER had fossil fuel consumption greater than 19th century levels, we would still be fucking with the climate on a multiple of the scale of the largest short-term geological temperature excursion that we know about.
And we're already doing like 15 times that.
I think glacial cycles have bigger temperature swings: just eyeballing a graph I made based on data from the Vostok core, it's about 10 degrees. However they are not initially triggered by CO2, although they are hugely amplified by it. They're also much slower than what is happening now: I worked out that the most recent deglaciation was about a degree per 840 years: we're doing close to 10 times that currently. Within limits it's the rate of change that is bad, not the change: this is what the idiot 'but the climate has always changed' trolls are avoiding understanding. It would be interesting to know how the dinosaurs (or the non-bird ones) would have done if the event that killed them had happened over a few thousand years rather than a few days: I bet they'd still be here now.
So, the clathrate gun may be going off soon, sounds like.