Climate change doesn’t care whether you believe init or not. And it may get worse
It’s not funny when people die of the cold but there was some innocent amusement to be had from the indignation of Texans unable to boil their drinking water during the ‘Big Freeze’ because the power was still out. Things like that are not supposed to happen in a modern, developed country like the US of A. How dare they? Others, aware that Texas has cut every corner in public services that it’s possible to cut, were unsurprised by the five-day mini-disaster that struck the country’s second-biggest State. One blogger wrote philosophically: “Occasionally, something will happen in Texas to remind the people who live here that we live in a failed State.” A winter temperature 25°C colder than usual for the time of year is rare, but this is not the first time it has snowed in Texas. The electricity failed, triggering a cascade of other disasters, mainly because of a long-standing refusal to connect the State power grid with the two main national ones. (This was done to avoid federal supervision on prices and standards). Others have cold snaps too. Germany, Russia, Canada, even northern China get much colder than Texas, but they don’t end up freezing in the dark because they are prepared for it.
Texas could have been prepared for it, too, but somebody in power would have had to read science journals for that. Since they almost all got elected with donations from fossil fuel producers, that was never very likely. The “explainers” in the media talk about a rogue ‘Arctic vortex’, but what’s really happening is much simpler.
It’s just what global warming has done to the northern hemisphere’s ‘jet stream.’ The northern jet stream is a high-speed, high-altitude atmospheric “river” that flows from the West to the East all the way around the planet. It marks the boundary between the Polar air mass, sometimes called the ‘Polar Vortex’, and the warmer air masses of the mid-latitudes. East-bound airliners crossing the North Atlantic and the North Pacific often hitch a ride on the jet stream, saving up to an hour. The energy that drives the jet stream comes from the temperature difference between the two air masses it divides. However, the Arctic is warming much faster than the rest of the world, so that difference is shrinking and, with less energy the jet stream is slowing down. It used to blast straight East but even then it occasionally developed long S-shaped kinks called ‘Rossby waves.’ These are big loops extending far North and South of its usual track. As it has slowed down (the average speed is now 150-225 kmph), the Rossby waves have grown more frequent and bigger. They are often now great loops deviating from the straight track and bring with them cold Polar air rarely seen so far South, or warm air not seen previously so far North. That’s what happened to Texas last week: One of those Rossby waves brought cold Arctic air all the way South. This pattern will recur and Texans will have to live with it.
Climate change doesn’t care whether you believe in it or not. And it may get worse. In June-July 2018 record-breaking heatwaves hit western US, Western Europe and the Caucasus-Caspian Sea region, while there was extreme rainfall and flash flooding on the US east coast, in eastern Europe and Japan. It was all happening in big Rossby loops that had taken over the jet stream. All the loops, containing hot dry air or cool moist air, were stuck for over two weeks. By last year, researchers had found that over the last 20 years the same pattern of seven stalled peaks and lows over the same regions has lasted seven times for more than two weeks. In the previous 20 years (1980-2000), that had not happened even once. This suggests that the pattern is getting stronger. And, since the latitudes where the loops are stalling include most of the major “breadbasket” regions of the northern hemisphere, the crop-killing droughts and heatwaves they bring could cause a big loss in world food production. It’s the unknowns that do the worst damage.
(Gwynne Dyer’s new book is ‘Growing Pains: The Future of Democracy and Work.’ The views expressed are personal.)