I covered the polar vortex thing pretty well already, so you do not need me to remind you again how it works. On the other hand we all could use a reminder of how this stuff matters. You see, aside from trafficmaggeddon and your frozen nuts things are happening up north that could soon become a problem for everyone. I highlighted Nome, Alaska earlier because most people know something about it and it hit forty six freaking degrees in Nome, but in fact aside from tree-killing invasive critters moving north, melting permafrost and the coming mosquito season straight out of the book of revelations the weather in Nome is not THAT big a deal. I mean, it will suck a little more to live in Alaska if you make buildings or live in them, but it does not threaten the rest of us all that much. Well ok, that pipeline has its foundations in permafrost, so that could be a problem. But I digress.
The other day I read that Greenland had its own endless summer this year.
Alaska isn’t alone. Greenland has been about 5°C warmer than normal in January. This year’s snow season has shrunk in the northern hemisphere by about three weeks, leaving the people who plan Winter Olympics grappling with how to adapt.
That concerned me a bit more so I looked it up (graphs adapted from Weather Underground).
Note last month’s temperature in red against the historical average maximum and minimum daily temps in blue. You can see that Greenland has had a pretty half-assed winter.
I do worry that we will miss arctic sea ice. Open water and green land or dirt absorb a lot more heat energy than ice. After the albedo threat you have these ginormous reserves of methane ice that might or might not explode out of arctic sediments as they warm up. So ok, I am not exactly rooting for the northwest passage to open up for shipping year round. On the other hand at least arctic ice does not pose much of a threat RIGHT AWAY when it melts. Think of a glass of ice water left out in the sun. When floating ice melts the water level changes not at all. Greenland is more like a bucket of ice with a pool of water that gets higher and higher as ice piled up in the air melts away.
You could argue that Greenland represents a lot less of our big blue marble than the ice in a bucket with a little pool at the bottom. Though correct, I would respond that our human species likes to build expensive things really close to the water line. The oceans are miles deep, around 14,000 feet deep if you average the whole thing out, yet it will take just a few more feet to swamp north Florida, ‘bama and Mississippi in a flood of refugee cockroaches, Burmese pythons and trigger-happy racists. Three more feet and one hundred forty-one thousand people in New York City alone will commute by rowboat. Greenland has enough ice to add about twenty-four feet to the global total if its glaciers melt, as they seem increasingly inclined to do. That would put about one in ten of everyone on Earth a very tight spot, and by ‘tight spot’ I mean a refugee camp.
If it comforts you to think this is some hand-wavy science that might get overturned by a new fad in a few years, great. I hope you live a ways uphill from the sea. In truth this is pretty basic physics. A glacier only survives where the annual average temperature is below some hard number. Historically you would only find, say, a stable shelf of sea ice where the annual ‘isotherm’ was -9 degrees C or lower, though ice shelves fall apart at colder average temperatures now because ocean currents have gone screwy. Glaciers will only remain a thing in Greenland if the average temperature stays low enough for them to hang around. Cross that threshold and those pools of open water that show up in the summer will last a little too long and cover a little too much area, helping to split glaciers and ice shelves into more digestible chunks and lubricating the great ice river when a pool finds or creates a gap in the ice and drains to the bottom.
If the year-round average temperature goes up in Greenland by five degrees C then the area where glaciers stick around will get quite a lot smaller. Expect tidal surge floods like Hurricane Sandy to become an annual thing and then a monthly thing and then just how things are all the time as glaciers in the the new no-ice zones crumble and melt their way to the sea.