The hazards are many. And they seem to come in all forms.
The southwestern U.S. is reeling from record rainfall and extensive flooding from a rare tropical storm. Much of the central and southern parts of the country are in the grips of yet another oppressive heat wave. Nearly two weeks after catastrophic wildfires devastated the Hawaiian island of Maui, more fires are raging in the Pacific Northwest. And after a quiet start to this year’s Atlantic hurricane season, activity in the basin is ramping up.
All told, the various extremes are making for a turbulent week in nearly every corner of the country. Climate scientists also say it’s an all-too-real look at how global warming increases the risks — and consequences — of the deadly events.
“We’re looking at a multi-hazard situation, where we’re being hit by a string of different events over a short period of time,” said Gonzalo Pita, an associate scientist and expert in disaster risk modeling at Johns Hopkins University. “It’s like a double or triple whammy, and when they happen frequently or at the same time, the negative effects are compounded.”
While it's sometimes difficult to measure the exact role of climate change in any particular weather event, scientists know that global warming is having an overall effect on the frequency and severity of such events. Studies have shown, for instance, that heat waves and drought are more likely in a warming world. Dry conditions subsequently increase the risk of wildfires.
Similarly, warmer-than-usual oceans are a key ingredient for tropical storms and hurricanes to form. A warmer atmosphere can also hold more moisture, making the storms rainier and likelier to cause flooding.
Those types of compounding risks will be on full display this week.
Tropical Storm Hilary on Sunday became the first to hit Southern California in 84 years, dumping record rain over the region and causing widespread flash flooding. Though Hilary has weakened into a post-tropical cyclone, 26 million people were still under flood alerts Monday across parts of California, Arizona, Utah, Nevada, Oregon and Idaho.
In the Atlantic Ocean, meteorologists are tracking three named storms.
Tropical Storm Franklin is expected to dump heavy rain over the Dominican Republic and Haiti on Tuesday. A tropical depression, dubbed Gert, is predicted to weaken and dissipate soon, but the National Hurricane Center is also monitoring Tropical Storm Harold in the Gulf of Mexico, which is expected to hammer South Texas with strong winds and 3 to 5 inches of rain over the next 48 hours. The National Oceanic and Atmospheric Administration revised its seasonal hurricane forecast this month from "near-normal" to "above normal."
Meanwhile, a heat dome — when a high-pressure system parks over an area, trapping hot air like a lid — is baking the middle part of the country, with high heat and humidity projected to linger through the week and into the weekend.
Heat index values, which represent the “feels like” temperatures when humidity and air temperatures are combined, are already soaring well into the triple digits in parts of Iowa, Kansas and Missouri. On Sunday, heat index values in Lawrence, Kansas, hit 134 degrees Fahrenheit, and St. Louis reached 117 F, the city’s fourth-highest temperature on record.
On Monday, 90 million people were under heat alerts from the Midwest through the Southeast.
The heat, combined with gusty conditions over Texas and Louisiana, is escalating threats from wildfires in both states.
Upstart weekend wildfires and a dose of smoke billowing in from Canada sent air quality plummeting across the Pacific Northwest over the weekend. Two deaths were reported after wildfires bore down on several communities in Washington state and forced mass evacuations.
Seattle had the worst air quality of any major city in the world Sunday, according to the global air pollution monitor IQAir. Portland, Oregon, ranked third worst.
Several wildfires sprouted up in Eastern Washington on Friday, spurred by hot, dry and windy conditions that primed the landscape for fast-moving blazes.
The Gray Fire, which began Friday afternoon, grew to more than 10,000 acres by Saturday morning and crossed Interstate 90, the region’s primary traffic artery, forcing the evacuations of several towns. Law enforcement officers were running door to door Friday telling people to flee their homes in the community of Medical Lake, Spokane County Sheriff John Nowels said.
One person was found dead after the fire roared through the town. At least 185 structures were damaged, and many homes were reduced to rubble. Officials discovered another death after the Oregon Road Fire burned more than 10,000 acres near Elk, Washington. The Oregon Road Fire was not contained at all Monday morning.
Air quality deteriorated Sunday in Seattle, reaching “unhealthy” levels, according to the National Weather Service. The smoke began clearing out of the city Monday as flow from the Pacific Ocean began to push the haze eastward.
The myriad disasters should be a wake-up call about society’s vulnerabilities to climate-aggravated hazards — and the need to mitigate and adapt to the realities of a warming world — said Andrew Kruczkiewicz, a senior staff research associate at the Columbia Climate School at Columbia University.
“We need new approaches to preparedness because of these complex emergencies and compound risks,” Kruczkiewicz said, citing not just the effects of climate change but also the rampant spread of misinformation, changes in how people seek out information and other challenges to emergency management.
Figuring out how to proactively address climate hazards has enormous implications, Kruczkiewicz added, because while such extreme events can affect anyone in any state, the socioeconomic impacts tell a different story.
“We see disaster impacts in areas that have been traditionally underserved and de-prioritized,” he said. “And there are reasons for that, because we have made decisions at the policy level to allow lower-income populations to remain in areas that are at heightened risk.”