Across much of the central and eastern United States, people are waking up on Wednesday to extreme cold. Extreme cold. Minneapolis is gripped in iron cold approaching 30 degrees below zero, and temperatures in Chicago are lower than they are for most of the Arctic Circle as the polar vortex, the counterclockwise low-pressure system that usually spins around the North Pole, detaches and swings across the upper Midwest. The painful, dangerous cold will continue to spill east, bringing dangerous lows to areas in the eastern part of the country as those areas now taking the brunt of the cold begin to get some much-needed relief.
At the same time, Australia is being blasted by almost unbelievable heat. Headlines have tended to describe it using animal stories, tales of snakes sheltering in toilets or flying foxes tumbling from the sky, but what those stories are describing is really a heat event even more deadly than the cold sweeping across the United States. Temperatures have run over 45 degrees Celsius (about 113 Fahrenheit) in city after city, day after brutal day. In some areas, temperatures have hovered close to 120 F, while overnight temperatures have been barely dipping below 100 F. The continuing heatwave in Australia is a genuine ecological disaster, threatening the continued existence of species already under stress, and bringing fires to a blistering, dry landscape.
Both situations are taking the lives not just of animals, but also of human beings. The Midwest cold has been especially punishing for the homeless. The United States has nothing close to enough space provided to bring people in from even the most deadly conditions, and what shelters are available often contain conditions that the homeless find less tolerable than the street. As the New York Times reports, Chicago alone has 80,000 homeless facing a night and a day with conditions literally worse than those in parts of Antarctica.
Counterintuitively, the beyond-frigid temperatures threatening the United States don’t come about because conditions at the North Pole are becoming more intense. When the polar vortex is at its strongest, it’s also well-organized—that is, a kind of hurricane-like structure that circles tightly just where its name suggests, at the pole. It’s only as the system weakens that it stumbles. The disrupted vortex stumbles, wobbles, and can split or shift far from the pole. As it has this week.
Perversely, the reason the vortex so weakened that it has tumbled into a deadly assault on the United States, and the reason that Australia is roasting, are the same. We’re the reason.
Human-generated climate change is the reason.
No matter how many tweets or commentaries try to conflate the cutting cold of this January with claims that climate change is not happening, the opposite is true. Climate change is global warming. Human-generated pollution has altered the composition of the atmosphere to such an extent that it has disrupted the amount of heat the Earth retains from the Sun. That rapid change is bringing up the average temperature of the planet, raising the level of the oceans, melting ice caps, and destroying glaciers.
But that effect is by no means evenly spread out and smoothly distributed. Much of the heat the Earth has gained has been hidden in the ocean, where it affects the currents and water-surface temperatures that in turn drive weather over land. Heat is translated into effects that we can see not at all gradually, but in a lurch here, a jerk there, and disruption everywhere.
That disruption can be wildfires, or mudslides, or floods, or hurricanes, or deadly heatwaves—or, as counterintuitive as it might seem, a week of crushing cold. Because consistent seasons require stability. Climate change has killed that stability.
As the New York Times reports, we have entered “an age of weather extremes.” And those extremes are simply becoming more … extreme year by year as we drive the system into greater spasms of instability. Crystal A. Kolden, an associate professor in the University of Idaho’s College of Natural Resources, told the Times that “When something happens — whether it’s a cold snap, a wildfire, a hurricane, any of those things — we need to think beyond what we have seen in the past and assume there’s a high probability that it will be worse than anything we’ve ever seen.”
The effects we’re seeing now, including the bouts of Arctic cold, are not unexpected. Climate change models have predicted exactly this effect as changing conditions around the pole weaken and disrupt the polar vortex. And conditions at the pole have changed much, much more than they have across most areas where people live. It’s much warmer there than at any time in the historical past. With changing currents and melting ice, the conditions around the North Pole are like nothing that human beings have seen since they first became capable of taking measurements in the area.
Not every weather event is climate change, not even every extreme weather event. But the reason that this is the age of the extreme, the age when records just keep falling, and when the 20 warmest years on record have all happened in the last 22 years, is certainly the result of climate change. As is the consistent weakening of a system previously unknown to most people, turning “polar vortex” into part of the common vernacular.
Unpredictable extremes are likely here to stay. Not every winter from now on is going to have a week of temperatures as awful as those brought by the vortex in 2019, but predicting what the vortex will do—will it split this year? Will it dip across the U.S.? Tilt toward Russia? Become generally disorganized?—has already become an annual game.
Global warming is, quite rapidly, bringing up the average temperature of the planet. And that wrenching change is bringing with it ugly, jagged, extreme disruptions that can be measured by extremes—even extreme cold. Ultimately, should that warming continue, the ravages of the polar vortex might diminish because the whole system will be so weakened, and the whole Arctic so warmed, that there simply will no longer be that pool of icy air to move around. That might be a relief for the people who live in those times—but those people are likely to be dealing with too many of the other disruptions of climate change, including civilization-toppling political instability and environmental destruction, to feel much gratitude.
Wednesday, Jan 30, 2019 · 5:46:18 PM +00:00 · Mark Sumner
Another extreme event for your Wednesday.