Those of un in the Northwest part of the US know how unusual the recent heatwave was drawing from our own life experience. Now scientists have quantified how extraordinary this weather was, and suggesting a direct casual link to climate change.
During the last days of June 2021, Pacific northwest areas of the U.S. and Canada experienced temperatures never previously observed, with records broken in many places by several degrees Celsius.
Currently available mortality estimates of at least several hundred additional deaths are almost certainly an underestimate. The full extent of the impact of this exceptional heat on population health will not be known for several months.
Scientists from the US, Canada, the UK, the Netherlands, France, Germany and Switzerland collaborated to assess to what extent human-induced climate change made this heatwave hotter and more likely.
Main findings
- Based on observations and modeling, the occurrence of a heatwave with maximum daily temperatures (TXx) as observed in the area 45–52 ºN, 119–123 ºW, was virtually impossible without human-caused climate change.
- The observed temperatures were so extreme that they lie far outside the range of historically observed temperatures. This makes it hard to quantify with confidence how rare the event was. In the most realistic statistical analysis the event is estimated to be about a 1 in 1000 year event in today’s climate.
- With this assumption and combining the results from the analysis of climate models and weather observations, an event, defined as daily maximum temperatures (TXx) in the heatwave region, as rare as 1 in a 1000 years would have been at least 150 times rarer without human-induced climate change.
- Also, this heatwave was about 2°C hotter than it would have been if it had occurred at the beginning of the industrial revolution (when global mean temperatures were 1.2°C cooler than today).
- An estimated one billion marine animals died in the Salish Sea off the coast of Vancouver during the heatwave.
- The numbers are projected to increase as climate change triggers rising temperatures in many parts of the world.
It wasn’t just hot enough to fry an egg on the blacktop during the recent heat wave in the Pacific Northwest. It was hot enough to cook millions of mussels alive and kill up to a billion marine animals, says one expert.
My town’s largest private employer is a seafood company specializing in mussels. But those are commercially grown from floating rafts, and aren’t left exposed to heat and sun at low tide.
Did you endure the recent Northwest heatwave? What did you experience?
UPDATE:
This evening we’re having another complex of thunder storms over the North Cascades and Southeastern British Columbia according to the local TV weather people. Will they ignite the tinder dry forests?