Yes, blame climate change.
Global warming triggered by man has triggered a heat wave that is probably killed hundreds of people last week across the northwestern U.S. and Canada.
The huge accumulation of greenhouse gases in the atmosphere has made an unprecedented weather event 150 times more likely, according to analysis by World Weather Attribution. The a loosely connected team of global scientists he concluded that an extreme heat wave would be “almost impossible” without climate change, which has already warmed the planet by about 2.2 ˚F (1.2 ˚C).
Scientists have long resisted tying any weather event to climate change, adhering to the general view that heat, droughts, fires and hurricanes will be more frequent and stronger. But more satellite data, increased computing power, and higher-resolution climate simulations have made researchers more confident in stating, often within days, that global warming has significantly increased the chances of certain disasters. (See 10 Breakthrough Technologies 2020: Attributing to Climate Change.)
Extreme temperatures last week broke the heat record of all time in cities and towns throughout the region, power off tens of thousands of homesand accommodated more than 2,000 people in the emergency services for heat-related illnesses in Washington and Oregon.
So far, officials have reported more than 100 heat-related deaths in those states, according to assorted media. In addition, there were almost 500 “sudden and unexpected deaths” in British Columbia, which is about 300 more than is normal in the corresponding five-day period.
The most likely scenario is that higher global temperatures simply exacerbated the effects of unusual atmospheric conditions that occurred last week, when the so-called thermal dome trapped hot air in much of the region. If this is the case, similar events could occur once or twice a decade if temperatures rise by 3.6 ˚F (2 ˚C), the researchers found.
Even more troubling, albeit a thin possibility, is that greenhouse gas emissions have pushed the climate system beyond some unknown and little-understood threshold, where global warming is now causing sharper rises in extreme temperatures than expected. Further research will be needed to assess this theory. But that would mean that strong heat waves will exceed the level predicted by current climate models, the researchers said.
“You shouldn’t break records by four or five degrees Celsius (seven to nine degrees Fahrenheit),” said in a statement Friederike Otto, co-chair of World Time Attribution and associate director of the Institute for Environmental Protection at Oxford University. . “This is such a remarkable event that we cannot rule out the possibility that today we have extreme heat that we expected to only come to higher levels of global warming.”
One more heat wave is expected in order for temperatures to return to three-digit figures across parts of the northwest in the coming days.