The Portland Streetcar is 20 years old, making it relatively sprightly for infrastructure in the United States. Yet it was built for a different geological epoch. On Sunday, while Portland suffered through what was then its hottest day ever, the system started to melt. As the temperature reached 112 degrees Fahrenheit, a power cable on a major bridge warped, twisted around some metal hardware, and scorched. Elsewhere, the wires that run above the track expanded and sagged so much that they risked touching the train cars. By mid-afternoon, the streetcar system had shut down. The trams, which run on 100 percent renewable energy, seem to offer exactly the sort of urban fast transit that the country needs to reduce carbon pollution. But they were not prepared for—they could not withstand—one of the region’s first wrenching encounters with the remade atmosphere.
At first blush, there isn’t much to say about the “heat dome” settled over the Pacific Northwest like a shroud. Here is the story: It is very hot. Portland’s hottest three days on record have been the past three: The city broke its all-time record on Saturday (108 degrees Fahrenheit), smashed it on Sunday (112 degrees), and broke it again yesterday (116 degrees). Seattle-Tacoma International Airport also set an all-time heat record yesterday (108 degrees). Farther north, the temperature in the town of Lytton, British Columbia, yesterday reached 117 degrees Fahrenheit, or 47.5 degrees Celsius—the hottest temperature ever measured anywhere in Canada. America’s northern neighbor now has the same all-time heat record as Las Vegas, hundreds of miles to the south. Portland’s all-time record now exceeds the all-time records for Dallas, Austin, Houston, and Atlanta. It is very hot.
A heat dome is a hot-air balloon, thwarted. Hot air wants to rise, expand, and push up. Normally, when such a process happens at meteorological scales, it cools the planet’s surface or helps create thunderstorms. But in a heat dome, the air’s rise is impeded by a high-pressure system sitting on the atmosphere. When the air tries to rise, the system above nudges it back down to the surface. As the air descends, and more and more of the atmosphere’s weight settles on top of it, it becomes denser and hotter. Then it tries to rise again; it once again hits the barrier above. The air can’t escape this cycle, so it just circulates up and down, getting hotter and hotter.
Extreme heat is colorless, odorless, and silent; like heart disease, its reality seems abstract until it happens to you. Then it kills. In most years, heat is the deadliest type of weather event in the United States. At least 600 and possibly as many as 1,500 Americans die every year of heat-related disease, although the real numbers may be higher because all-cause mortality rises during heat waves.
Heat is deadliest in places where people do not have air-conditioning. In 1995, a heat wave in Chicago killed 739 people in six days. Most victims were elderly people who lacked air-conditioning and lived alone, according to the sociologist Eric Klinenberg. Since then, American cities have improved their heat-emergency strategies—opening high-school gyms as community cooling centers, for instance—but the Pacific Northwest remains vulnerable to a cataclysm. In 2009, a study found that Pierce County, Washington, at the armpit of Puget Sound, was among the 13 census tracts most vulnerable to heat waves nationwide. Today in Seattle, less than half of residents have AC.
That will almost certainly change. Some weather events—such as hurricanes and tornadoes—are at least dicey to connect to climate change. Heat waves are not one of them: Longer, larger, and more intense heat waves are what scientists have expected to see from climate change for decades. In the climate of the 20th century, the heat dome was a one-in-1,000-year event, according to Jeff Berardelli, a meteorologist at CBS News, but the warming climate is making it much likelier.
The Biden administration has been teased for trying to stuff climate change into an infrastructure frame. But this week has affirmed the basic logic of its move. Adaptation, long the neglected arm of climate policy, will need to lead our efforts to address rising global temperatures. “Most of the infrastructure that we’re going to use in the next several decades, it’s already here; it’s already in the ground,” Constantine Samaras, an engineering professor at Carnegie Mellon University, told me. “We have to figure out ways to make that stuff, those systems, resilient to increasing extremes.”
So far we haven’t met that standard. Even as the climate has diverged from its long-time normal range, the construction of physical infrastructure has not. “The public might look at engineering and say, ‘Of course they’re designing for a future climate; it would be silly if they weren’t,’” Samaras said. “But we’re basically not doing it.” In 2018, he and his colleagues looked at whether any state department of transportation was planning for the precipitation thresholds of the future. Essentially none of them were, he said.
Since then, a few states have integrated the new normals into their highway manuals. But even if you know that climate change will happen, bending civil engineering to that future isn’t easy—and, at least for now, it requires some art and argument. An engineer building a bridge can test and calculate how much weight it can bear, and another engineer can check the math, Samaras said. No such standard exists for the climate, and “engineering standards take a long time to propose, promulgate, and get adopted.” Even if an agency—the National Oceanic and Atmospheric Administration, perhaps—started this work now, another decade would pass without resilience standards.
In the short term, though, the Oregon and Washington heat dome will likely drive one clear shift—specifically, a lot of air-conditioning adoption. In past years, climate advocates have sometimes framed AC as a luxury, in part because of its intense energy consumption. This week should disabuse climate experts of that idea, Samaras said, and reveal that AC is a worthy form of climate adaptation.
This mass adoption could bring about a “step change” in infrastructure, leading to permanently higher electricity use in the summer in the Pacific Northwest. Utilities will have to make sure they meet that demand with zero-carbon electricity—and build a grid that can withstand high temperatures. It’s one more way that climate change will force us to improve every part of our society at once or suffer the consequences.
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