A Crazy North American Winter
I believe it was Fox News’ Sean Hannity that once mocked “climate alarmists” when he jokingly said “When it snows, it’s climate change. When it’s cold, it’s climate change.” However, there is a link between the extreme cold snaps we have experienced this winter and climate change. There is also a link between climate change and the historic blizzard tearing through Atlantic North America.
First, the temperature. From where I sit in Prince Edward Island, fall and early winter were mild and wet, which has become the norm. However, a few weeks ago, it got cold. And I mean icicles-on-your-noze-hairs-in-two-minutes cold. And it stayed like that for about a week. But, a few days after the frigid cold, on January 30th and 31st, we broke heat records, the temperature reaching 11,2 degrees Celsius in Charlottetown! Then, it got cold again. And right now (as I type), we are in the middle of a blizzard – which I’ll get back to in a minute.
What do these extreme temperature swings have to do with climate change? For the answer, we look to from Paul Beckwith, part-time professor and PhD student of abrupt climate change in the Department of Geography at the University of Ottawa: (Thanks to Christine at 350 or bust for having posted this quote and the video that follows!)
Normally the high altitude jet streams that circle the planet are predominantly from west to east with little waviness. Weather is cold and dry northward of the jets (Arctic air sourced) and warm and wet southward (moist tropics and ocean sourced). Now, and moving forward, the jets are extremely wavy and as the crests and troughs of the waves sweep by us each week we experience the massive swings in temperature. The extreme jet waviness is due to a very large reduction in the equator-to-Arctic temperature gradient caused by an exponentially declining Arctic reflectivity from sea-ice and snow cover collapses (which causes great amplification of Arctic temperatures). Additional amplification is occurring due to rapidly rising methane concentrations sourced from sea-floor sediments and terrestrial permafrost.
Observed changes will accelerate as late summer sea-ice completely vanishes from Arctic within a few years. Largest human impacts will be food supply shortages and increases in severity, frequency, and duration of extreme weather events.
And for those of you who are more audio-visual learners, here is professor Beckwith giving this same explanation in video format:
That explains cold-and-hot swings. Now, what about this “Historic Blizzard” that is dumping massive amounts of snow throughout Atlantic North America? How is that affected by climate change?
For that I turn to Joe Romm at Climate Progress. Mr. Romm asked Dr. Kevin Trenberth, former head of the Climate Analysis Section at the National Center for Atmospheric Research, what role climate change is playing on this historic storm. Here is what he said:
- This is a perfect set up for a big storm, with the combination of two parts: a disturbance from the Gulf region with lots of moisture and a cold front from the west.
- Ingredients for a big snow storm include temperatures just below freezing. In the past temperatures at this time of year would have been a lot below freezing but the ability to hold moisture in the atmosphere goes down by 7% per degree C (4% per deg F), and so in the past we would have had a snow storm but not these amounts.
- The moisture flow into the storm is also important and that is enhanced by higher than normal sea surface temperatures (SSTs). These are higher by about 1 deg C [almost 2°F] than a normal (pre-1980) due to global warming and so that adds about 10% to the potential for a big snow.
And as you can see from the graphic below, Winter Storm Nemo is part of trend of increasingly powerful storms in the Northeast of the USA.
So, there you have it Mr. Sean Hannity. Climate change isn’t as simple as “it’s gonna be hotter all the time”. It’s much more complicated than that. And it’s much more dangerous than that as well. The past 12 months have given us a look at what climate change looks like. And, unfortunately, we are just seeing the beginning of what is to come. So, we need to get our collective act together and “get serious about climate change, like our lives depended on it“.