That’s bad enough, but what follows in this analysis is worse. Please stay with me while I quote it at length, because the scary part comes at the end:
“The observed temperatures were so extreme that they lie far outside the range of historically observed temperatures. This makes it hard to quantify with confidence how rare the event was. In the most realistic statistical analysis the event is estimated to be about a 1 in 1,000 year event in today’s climate.
“There are two possible sources of this extreme jump in peak temperatures. The first is that this is a very low probability event, even in the current climate which already includes about 1.2°C [almost 2.2 degrees Fahrenheit] of global warming — the statistical equivalent of really bad luck, albeit aggravated by climate change. The second option is that nonlinear interactions in the climate have substantially increased the probability of such extreme heat, much beyond the gradual increase in heat extremes that has been observed up to now. We need to investigate the second possibility further, although we note the climate models do not show it.”
Note the phrase “nonlinear interactions.” The possibility the authors raise is that the warming we have already caused may have somehow triggered sudden and unpredictable changes in weather patterns, including the frequency and intensity of extreme events.
What kinds of events, hypothetically, might those be? We don’t have to imagine these scenarios. The torrential, almost biblical rainfall last week in Germany and Belgium, which caused unprecedented flooding that washed away picturesque villages and claimed at least 200 lives, might be one example. So is the similar deluge this week in China’s Henan Province, which caused flooding and a final death toll that has yet to be tabulated.
This year’s fire season in the American West is already worse than last year’s, which was horrific. As of this writing, the National Interagency Fire Center reports that 79 significant fires have torn through 1,448,053 acres of land. Among these conflagrations is the Bootleg Fire in Oregon, which is so big and hot that it creates its own local weather. The wildfires are generating so much smoke that impacts have reached the East Coast. On Tuesday, New York had its worst air quality in 15 years because of smoke brought there by high-altitude winds from the other side of the continent.
Skeptics often attack climate scientists for alleged overconfidence in their predictions about the disastrous impact of climate change. But leading researchers are being honest, and humble, about the extreme weather we’re seeing. World Weather Attribution calculated that if we have another 1.4 degrees Fahrenheit of warming — which is projected to occur by the 2040s, unless we take bold action — an extreme heat wave in the Northwest like the one we just saw would no longer be expected to happen every 1,000 years, but “roughly every 5 to 10 years.” But if some “nonlinear” process is happening, the scientists have no idea what we should expect, and they acknowledge it.
Michael E. Mann, director of Pennsylvania State University’s Earth System Science Center, told CNN that “the signal is emerging from the noise more quickly” than climate scientists’ models predicted. “The signal is now large enough that we can ‘see’ it in the daily weather.”
It’s clear to me that we are now at the point where the old disclaimer about not being able to ascribe any specific weather event to climate change no longer applies in the way it used to. Thousand-year floods or fires or storms are supposed to be, by definition, rare. When they happen in bunches, all around the world, obviously something is going on.
The question is: What, precisely? The models climate scientists developed told us that these kinds of events were our future. If the future is now, we’ll need to figure out what’s going on and how to respond to it fast. The luxury of dithering and delay has gone up in smoke.