Bree Oswill gathered all the blankets and towels she could find and taped them to every window that didn’t have a shade as the temperature soared past 100 degrees. She didn’t have central air conditioning and wanted to keep as much sunlight and heat out as possible.
Growing up in Portland, Oregon, Oswill has become increasingly concerned about the extreme weather changes she sees year after year, from wildfires to heat waves.
It’s like a pandemic, says the 44-year-old mother of two, but it’s never-ending.
“It’s like a lockdown, but we’re not going to solve it by putting on a mask or getting a vaccine,” Oswill told CNN. “It’s just sort of perpetual. It’s scary.”
Even though it is not yet July, a month when Oswill and many Portland residents typically experience the hottest days of the year, a historic heat wave is wreaking havoc across much of the Pacific Northwest.
Three days in a row, Portland set an all-time high temperature. Seattle also broke its own record, which it had set on Sunday. On the other side of the border, Lytton, British Columbia, set all-time high temperatures on Sunday and Monday, with temperatures shockingly 48 degrees above normal.
The heat wave is “unprecedented,” according to Kristina Dahl, a senior climate scientist at the Union of Concerned Scientists.
“We saw heat records over the weekend only to be broken again the next day,” Dahl told CNN, “particularly for a part of the country where this type of heat does not happen very often.”
Heat waves are becoming more frequent and intense as a result of climate change, according to Michael E. Mann, a climate scientist at Pennsylvania State University. “You warm up the planet, you’re going to see an increased incidence of heat extremes,” Mann told CNN.
Climate change, according to experts like Dahl and Mann, is reshaping the planet’s weather patterns. More energy is added to the climate system as humans emit more planet-warming greenhouse gases into the atmosphere. According to Kristie Ebi, a climate and health researcher at the University of Washington, the excess energy manifests itself in extreme weather events.
“Heat waves have always occurred and will always occur, but we’ve got a very different pattern of heat waves now than we did a couple of decades ago,” Ebi told CNN. “And it’s not just the intensity, it’s also the geographic extent.”
On the other end of the country, over 40 million people in the Northeast US, including the New York, Philadelphia, and Boston metropolitan areas, are under heat advisories. Though temperatures in the Northeast will not be as hot as they are in Oregon and Washington, records for the date may be set before temperatures cool off on Thursday.
Extreme heat is one of the most deadly effects of climate change, killing more people than any other weather event.
Kate Weinberger, an environmental epidemiologist at the University of British Columbia, looked at the number of deaths in the United States each year caused by extreme heat. Because records typically only look at medical terms like heat stroke and ignore other potentially heat-related causes of death, such as heart attacks, a 2020 study led by Weinberger found an undercounted number of heat-related deaths in the country.
“Heat likely contributes to many more deaths from causes other than heat stroke, because heat can exacerbate other chronic diseases, such as heart and lung conditions,” Weinberger told CNN. “Given the danger posed by heat, events like the ongoing heat wave in the Pacific Northwest need to be taken very seriously.”
According to officials in Multnomah County, which includes Portland, there were at least 43 heat-related emergency department and urgent care clinic visits in the county on Friday, Saturday, and Sunday, as of Monday morning. “Ambulances are stretched thin due to demand,” the sheriff’s office said Monday.
“Normally we would expect about 1 or 2 visits for heat illness in the same time period,” Kate Yeiser, communications coordinator for Multnomah County, told CNN in an email. “The visits this weekend alone represent nearly half the heat illness visits we typically see during an entire summer.”
The number of premature deaths caused by heat exposure in the United States, particularly among babies and children left unattended in cars, is one of the most shocking aspects of heat-related deaths in the United States.
Ebi co-authored a study published in the journal GeoHealth in 2020 that found large increases in the number of premature deaths in the United States each year as the planet warms.
“Many don’t understand how fast cars heat up and how babies physiology can’t tolerate that,” Ebi said. “Ensuring that people are really aware about protecting babies and children during these heat waves is important.”
Mann suggests thinking of weather events on a bell curve to understand how the climate crisis is changing the playing field. The most common weather occurs at the highest point of the curve, while extreme events occur at the tails.
The bell curve shifts to the right as the planet warms, pushing already-extreme events into uncharted territory.
Climate models, according to Mann, can capture the shift and predict increases in extreme heat well into the future by predicting general global conditions. However, he claims that they do not provide a complete picture of climate change’s effects during the summer.
“This is an area where current generation models are not capturing a real-world climate connection,” said Mann, who was also the lead author of a study that shows climate change is causing the summer’s jet stream — fast-flowing air currents in the upper atmosphere that influence day to day weather — to behave oddly.
“In that sense, climate models are actually underestimating the impact that climate change is having on events like the unprecedented heat wave we’re witnessing out West right now,” Mann added.
During the summer, climate change may cause the jet stream to become stuck in a static wave pattern. The best way to demonstrate this, according to Daniel Swain, a climate researcher at the University of California at Los Angeles, is to flick a jump rope up and down until the waves appear to stop moving. Similarly, high and low pressure systems can become stuck in the atmosphere, resulting in extreme weather events such as severe heat, drought, and wildfires.