Children cooling off at a fountain near Portland, Oregon during a record-breaking heat wave in the west US and Canada on June 27, 2021
Even without climate change, the west United States and Canada could have seen a heat wave over the past week. Experts say that the severity and scale of the record-breaking temperatures was undoubtedly increased by changes in our atmosphere.
This week, the US states of Washington, Oregon, and British Columbia, Canada were boiled to death in record temperatures.
"This is one the most extreme heat waves we have ever seen anywhere on Earth in many years," Daniel Swain, a UCLA climate expert, said. He noted that temperature records rarely break by more than a degree.
He said, "In this instance, those records were destroyed." It's the sheer magnitude and persistence of this one that makes it truly shocking.
Canada broke an all-time record Tuesday. The temperatures in Oregon were more than those in Las Vegas in the middle Nevada desert.
All this is in an area with a temperate climate for this time of year.
A "heat dome" is the phenomenon that causes scorching heat. High pressure fronts trap hot air, which heats it up further as it is pushed back towards the ground.
Professor of atmospheric science at Oregon State University Philip Mote said, "It's kind of like a bike pump." "If you put air in a bicycle tire, it warms up the air."
This condition prevents the formation of clouds, which allows more radiation from sunlight to reach the ground.
These conditions are not uncommon. Karin Bumbaco from the University of Washington said that it was "similar to how we always get heat waves." We've seen this pattern before, but it was stronger than normal.
Climate like "steroids"
What is the cause of these record-breaking highs?
"A world without climate changes would still have had a heatwave in the Pacific Northwest. It would just have not been quite as record-setting," Zeke Hausfather, climate expert at Breakthrough Institute.
He said, "Climate can be like steroids for the climate." "If a professional baseball player or Olympic athlete takes steroids, they will still perform better on some days but their average performance is going up. Climate is similar to weather. This makes it more likely that it will experience extremes.
To determine the cause of an event, so-called "attribution studies" are conducted.
Bumbaco said that "it's safe to assume that at least some components" of global climate change contributed to this event.
The temperature is generally higher here, and the region has warmed by about three degrees Fahrenheit over the past 100 years. It makes sense to break records little by little.
Swain, a UCLA expert, stated that it is possible that climate change has increased the heat wave to an even greater extent.
The heat dome may have been strengthened by the drought, which has ravaged the region for weeks. This is because the sun's energy doesn't evaporate water anymore, but instead warms the atmosphere.
Swain said that climate change is already "increasing drought severity" in western North America. "The question of whether it would happen to such an extent without climate change is clearly not."
It is difficult to predict how many heat waves like this will again occur.
Swain stated, "This particular event is so extreme that even in a warmer climate, it will still remain unusual." It has moved from being almost impossible to something we might see again.
Hausfather stated, "The bad news is that even though we can wave a magic wand to get all our emissions down to zero tomorrow,"
"We are stuck with the warming... We need to be ready for these types of events to become more frequent."
Experts stress the importance of adapting in the medium-term. This includes equipping people with air conditioners, even if they emit harmful emissions over the long-term, by redesigning buildings to reflect heat rather than retain it, and by planting vegetation.
Mote stated that global greenhouse gas emissions can be reduced in order to avoid these problems from ever happening.