Heat waves and wildfires are everywhere this summer, but the global average temperature can easily climb higher.
Trains slowing to a crawl for fear of buckling railroad tracks. Wildfires licking the sides of a highway. Airport runways melting.
Reports of all sorts of heat-related calamities sweated forth from the U.K. this week, as the country saw its all-time highest temperature record fall multiple times over the course of a scorching Tuesday. Elsewhere in Europe, the heat wave fueled wildfires in France, Spain, Portugal and Greece, while in Asia, China expected temperatures in the triple digits across a number of provinces. In the U.S., parts of the Plains hit 115 degrees and more than 100 million people were under heat advisories.
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It may feel like the planet has reached a new and more extreme pinnacle of disaster, but from a pure numbers standpoint, this isn’t even a top five apocalypse.
The first six months of 2022 were only the sixth hottest such period on record, according to the National Oceanic and Atmospheric Administration, whose records go back to the 1880s. Though the next few months could bump 2022 up the list of warmest years, the NOAA said there is only an 11 percent chance this year will crack the top five. The chance it will set a record for hottest year is less than 1 percent.
It is a near certainty, though, that 2022 will join the top 10 warmest years, just as almost every year does at this point — a signal of just how much climate change is altering Earth’s temperature baseline. The most likely outcome is that 2022 will remain in sixth place, ranking behind 2016, 2020, 2019, 2015 and 2017, and just ahead of 2021. Other climate-monitoring agencies like NASA or the Japan Meteorological Agency have slightly different rankings, but all agree that essentially all the warmest years have occurred in just the past decade.
There will always be some year-on-year variance and randomness in global temperatures, and experts say the extreme events like this summer’s heat waves won’t necessarily depend on whether a given year ranks first or fourth or eighth. But climate change is cranking the whole system farther and farther into the red, leading to the grim, ever-updating top 10 list of warmest years and the potential for every heat wave to shatter the last one’s record.
“There is still natural variability in the climate system,” said Daniel Horton, an assistant professor who leads Northwestern University’s Climate Change Research Group, adding that only tiny slivers of a degree separate the top 10 warmest years. “The chances are that, if we continue to emit greenhouse gases, this record that we’re breaking this year in the U.K. will get broken in the near-term future. That’s what all trends are pointing towards.”
A cooling La Niña
One of the primary drivers of the within-apocalypse variation is the weather pattern known as the El Niño-Southern Oscillation (ENSO). At the moment, the oscillation is in the midst of a La Niña period, which is associated with a cooler ocean surface in the central and eastern Pacific and cooler global temperatures — likely an important factor in 2022′s place outside the top five.
“El Niño and La Niña, of course, have a very large impact because 70 percent of the planet is ocean,” said Emily Becker, a University of Miami climate scientist and a co-author of the NOAA’s ENSO blog forecasting and discussing conditions in the Pacific. “When you’re talking about the global temperature, you can have wild extremes over land. But the ocean itself is kind of a great regulator.”
The La Niña conditions are regulating global temperatures downward for the moment, but Becker said that isn’t likely a large driver of more localized variability like a heat wave. At the moment, La Niña is expected to continue through the fall and into the winter — its third-straight winter, a hat trick that has happened only twice before in the 73 years of available ENSO history — but when it inevitably flips to El Niño, we can expect the records to start falling again.
“If an El Niño gets kicked off in the middle of next year, I suspect we would shoot back up into that top two or three,” Becker said. “Possibly the warmest year on record.”
In fact, the World Meteorological Organization issued a climate update in May finding a 93 percent chance that at least one year between 2022 and 2026 will knock 2016 off its steamy perch. That period’s five-year average temperature is also 93 percent likely to be warmer than the previous five-year average — even though those previous years feature some of the hottest years currently on record.
New normal
Regardless of the ranking, experts agree the extremes currently hitting Europe, China, the U.S. and elsewhere are only going to get more likely.
“It doesn’t really seem that abnormal,” Horton said of those extremes. “When I think back to last year, you know, we had the huge heat wave in the Pacific Northwest” — a hugely deadly event deemed “virtually impossible” without climate change, according to scientists, he said. “And then everything caught on fire. And that was just in the U.S.”
He noted that while the impacts currently dominating the news are in rich parts of the world like the U.S. and Europe, there are other extreme events in places much less prepared for them, and that had much less to do with causing them. “It’s important to place the European heat wave in the context of these other heat waves and citizens that can’t necessarily go out and buy an air conditioner.”
Earlier this year, India, Pakistan and surrounding countries suffered through a prolonged heat wave in countries where many people work outdoors and air conditioning can be scarce. The heat wave was found to be 30 times more likely now with climate change than it would have been otherwise. Last week in Tunisia, 118-degrees Fahrenheit temperatures in the capital Tunis broke a 40-year-old record; the heat wave and wildfires there have damaged crops along with risking human health.
Those sorts of impacts are just going to keep coming now, and they’ll get worse as new “warmest year” records eventually fall.
“It doesn’t seem particularly remarkable, despite the fact that it’s pretty stinking remarkable,” Horton said. “This is what we call ‘summer’ now.”
Thanks to Alicia Benjamin for copy editing this article.
