Slate’s Bad Astronomer Reviews Video: Nasty Surprises in the Greenhouse
March 22, 2016
New interest in the video from last year, in light of Jim Hansen’s hotly discussed new paper.
On Twitter the other day, climatologist Michael Mann mentioned a denier trying to debunk global warming by saying that Iceland was having a record cold wave.
Mind you, in general this is trivial to debunk. There are two words in the phrase “global warming,” and one of them is global. Averaged over the entire planet, temperatures are going up. But there will always be some places, over some period of time, which will get colder. Even get record cold snaps!
But that area near Iceland is special.
The map above shows global temperature anomalies for 2015, deviations from the average (where the average is calculated over the baseline of 1951–1980). As you can see, most of the Earth was much warmer than average, but there’s a cold blob off Iceland and Greenland.
It turns out this blob is not just some random fluctuation. In fact, counterintuitively, global warming predicts this cold spot! Peter Sinclair, who makes very well thought-out and simple climate change videos, made an excellent one last year explaining this pretty clearly: