Climate change last summer—and more extreme weather, study suggests | Rare Techy
Want to get our news delivered straight to your inbox (see what we’ve done there)? Sign up for our newsletter here.
Last year’s deadly heatwave in the Pacific Northwest and BC could not have been caused by the effects of human-made climate change, according to new research from at Columbia Climate School.
In June 2021, Canada reached a high of 49.6 C in Lytton, BC, shortly before a fire broke out in the area and destroyed many homes in the village and the surrounding land. First Country.
Across the rest of BC and the wider Pacific Northwest (PNW), record temperatures will drop as a high-pressure weather system takes center stage for the week ahead. of summer. At least 619 people in BC died, making it the deadliest weather event in modern Canadian history.
According to the study—authored by Samuel Bartusek, Kai Hornhuber, and Mingfang Ting and funded by grants from the National Oceanic and Atmospheric Administration and the National Science Foundation—a combination of factors led to the massive heat
“It’s so big, it’s tempting to call it a ‘black swan’ event, it’s unpredictable,” Bartusek said in a statement. “But there is a boundary between the unpredictable, the real, and the highly anticipated that is difficult to categorize. I call this a gray frame.”
Climate change is the main cause of heat waves. “Over the past 70 years, the probability of such an event has increased from impossible to a multi-century event,” the study says.
The 2021 heat wave is 10.4 C above the temperature. According to the model, the probability of this event will increase 13 times with 2021 temperatures compared to those from 1986-2021, and 500,000-fold compared to 1950-85. Current odds of another heat wave like this in 2021 are 1 in 200 years. However, if global temperatures rise to between 2 and 4.5 C above pre-industrial times, the study warns that the risk of an event “beyond 2021” will increase rapidly, to 1 in 10 years by 2050.
However, a study from researchers at the University of California Los Angeles, published in October, found that a heat wave is a 1 in 10,000-year event, and subsequent events of the same scale is about 1 in 1,000 years between 2021 and 2100.
In other words, the Columbia study found that already occurring climate change is necessary to produce a 10 C change in temperature—and that future climate change will be intense the growth of those clusters.
One important factor is soil moisture. The PNW is a wet region that holds a lot of moisture in the soil. However, long-term drying of the soil is beginning to turn the region into a “transitional climate,” where the soil alternates between wet and dry. Moist soil and vegetation can cool the air, while water absorbs heat until it evaporates. In 2021, the soil was drier than normal, meaning that the soil itself warmed the area above. That effect is more pronounced in areas where the soil has been previously wet.
“In the PNW, drying can increase temperature variability more than in arid regions such as the western United States,” the study says. “The 2021 heat wave is an ominous sign of a regime change across much of the PNW from a wetter to a transitional climate, making events more intense.”
Bartusek says dry soil can also affect other types of extreme weather. In 2021, it will be followed by severe storms that cause severe flooding.
“Drier soils are likely to be more prone to flooding from the next rains,” he wrote in an email to Right. “It is possible that the heat wave and the dry and hot summer of 2021 contributed to the flooding later that year. This is an important area for future research.
A report from the Canadian Center for Policy Alternatives released Wednesday estimates that the combined cost for 2021 of house fires, wildfires, floods, and landslides in BC is between $10.6 billion and $17.1 billion, making it the costliest natural disaster in Canadian history (so far).
Despite the drying of the soil and the long-term effects of global warming, there is a chance for a heat wave, which is a short-term issue. The paper points to a different air stream as the main force. The North American air current carries winds west to east across the Northern Hemisphere, but before the 2021 heat wave its pattern changes to four major peaks and rivers that run north-south, “a pattern that affects North American wildfires.”
The peaks create high pressure weather systems that compress the air below and warm it. The higher the altitude, the higher the pressure and the hotter the air.
One of these four peaks was camped over the PNW and instead of moving inland, it stopped. While record high temperatures were recorded under all four high pressure systems, “the PNW saw more extreme temperatures … in contrast,” the report said.
BC will likely see more of these hot weather events moving forward. While coolers can help, and air conditioners can reduce the risk of illness, Bartusek says BC and the wider PNW are not prepared for extreme heat.
“Air penetration is very low in the PNW, and in addition, many PNW counties have very large outdoor farmworker populations and high social vulnerability, putting residents at high risk. ,” he said. Local governments have not done much: “Most of the important work to prepare people for the effects of heat and help those at risk has been done by social networks.”
The solution, Bartusek says, is not to change policies to protect against the harmful effects of heat. Blocking the vapors will cause the temperature to rise first.
“To prevent heat waves from becoming more intense, larger and longer, the fossil fuel industry and those who profit from emitting more CO2 must be challenged by collective action and government work, governments must take steps to transition our energy systems to renewable energy sources.”