Another (there have been several) study concludes that, around the world, heatwaves have become more severe in both frequency and duration. And, as predicted by others, they're really setting in across the equatorial and tropical latitudes.
The study found the escalation in heatwaves varied around the planet, with the Amazon, north-eastern Brazil, west Asia (including parts of the subcontinent and central Asia) and the Mediterranean all experiencing more rapid change than, for example, southern Australia and north Asia. The only inhabited region where there was not a trend was in the central United States.
Published in the journal Nature Communications, the study found a clear increasing trend in the total number of heatwave days within and across regions, and that heatwaves were getting longer across the past 70 years.A new focus - cumulative heating.
[Cumulative heat measures] how much additional warmth there was in an individual extreme heat event beyond the traditional threshold that defined the start of a heatwave.
The amount of cumulative intensity across heatwave seasons was found to have increased across the planet and the decades. The average increase per decade was between 1C and 4.5C (an increase of between 1.8F and 8.1F), though in some places – the Middle East and parts of Africa and South America – the rise was closer to 10C a decade.Like earlier studies this new report appears to corroborate the central thesis of "climate departure." This is a predicted phenomenon whereby a region reaches a point at which every year thereafter, every year, will be hotter than the hottest year in the previous era. The theory of climate departure predicts this shift will spread through the tropical regions during this decade, the 2020s. It is expected to first impact Central America and parts of the Caribbean. Since this theory popped up seven years ago I've been watching for some new science that refutes or even modulates its predictions.
For people living in the first affected areas, life could become much harder than it already is. Most of those economies are heavily agrarian. Human bodies can only take so much heat before they break down. Some warn that a farm hand's workday could shrink to just a few hours per day. The heat will also take a toll on crop yields none of which is good for areas already food insecure.
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As I write this I'm hoping I won't need to put the furnace on today. While people in the east have been roasting, it's been cold and damp out here. The local forecast for the rest of July calls for just two days that will break 20C - and those only by one degree. Lots of cloud. The silver lining? The forest fire situation might not be too severe this year. There's something. And besides there's always August, right? Isn't that right?
2 comments:
Do you sense that our BC climate is getting milder? Warmer winters, cooler summers? Maybe a fluke. Apricots and cherries have taken a big hit; too cold, too much rain.
An integral part of climate change theory is that traditionally dry areas will become hotter and dryer while ordinarily wet areas will become wetter. The Polar jet is now to the west of Vancouver Island meaning the Rossby wave is pulling cold weather out of the Arctic our way and as far south as southern Oregon. And, typical of Rossby waves, it's parking itself for a while. Remember the last time Calgary flooded? That was a Rossby wave that stalled over the foothills.
This is our new reality, Toby. How it is going to play out over the next decade or two isn't certain yet.
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