Climate change altering jet stream, causing storms to "get stuck"
There’s something really interesting happening with the jet stream right now. Dr. Jennifer Francis, research professor at the Institute of Marine and Coastal Studies at Rutgers University has been looking at what climate change is doing to jet stream patterns.
What’s happening is that the patterns of the jet stream are changing. Normally, as cold Arctic air mixes with warmer air from the south, the temperature differential moves the jet stream from West to East across our weather maps on the news each night.
With the Arctic ‘death spiral’ of unprecedented melting making the temperature difference between the cold air and the warm air smaller, this is slowing the jet stream down causing it to get stuck. Arctic amplification – where the Arctic is warming faster than most of the Northern Hemisphere is also causing the jet stream to meander, with higher ups and lower downs. So as the snow melts in Arctic and sub-Arctic areas earlier and earlier each spring, the jet stream keeps moving in new ways, causing more weather weirdness.
So what does this mean? It means weather patterns get more extreme and also stuck for longer periods of time. It’s how it was 90oF (32oC) in Alaska at the end of June, as the heatwave that saw record temperatures in Death Valley, California of 128oF (53oC) parked itself across the West of the continent.
It means that a storm that would have been normal for spring time in Calgary got stuck, and combined with warmer temperatures increasing snowmelt, led to devastating flooding of the Bow and Elbow rivers, a state of emergency and Downtown Calgary being underwater for the better part of a week.
The old jet stream path (solid line) and the new jet stream path (dotted line) image: Jennifer Francis via Yale Environment 360
It means that another storm over Toronto got stuck and dumped more than a month’s rain onto the city in two hours causing flooding that left people, cars and transit stranded and is still causing blackouts.
This is our new normal – welcome to your summers on climate change. Summers are now more likely to involve extreme heatwaves, extreme storms and flooding, weird and unseasonable snowfall, ongoing droughts, wild fires and other weirdness. This is what climate scientists have been predicting would happen and it’s now happening before our eyes.
As the Arctic continues to melt earlier and earlier each year, racing ahead to a totally ice-free summer for the first time in human history hundreds of years before the worst case scenario projections, it’s only going to get weirder. This fascinating (and also terrifying) interaction between long term climate warming and extreme weather patterns may very well be our first real look at non-linear climate disruptions.
Non-linear disruptions, while sounding great in a research paper, generally don’t mean much to people, especially because they are essentially unable to be predicted because they don’t follow easily recognisable patterns – they’re non-linear.
But now we’re seeing what they mean on the ground – scorching heat followed by pounding rain followed by bizarre snowstorms; then shake it all up, fork out billions for the repairs and start randomly drawing them out again. When events are non-linear you can’t properly plan for them; you don’t know when they’re coming you don’t know how big it will be or how much damage to prepare for.
Flooded Toronto, July 2013 (Graeme and Sara Bunton and Peel, flickr)
Know what we can plan for though? Reducing our carbon emissions to try and prevent the horror of 4 or even 6oC of climate change. This is what our future could look like if we don’t stop burning carbon as soon as possible. So let’s do that shall we?