Simulations show warming is making the deadly heat gripping the
Northern Hemisphere more likely. Millions of people across the
Northern Hemisphere are sweltering in extreme heat waves.
The recent, record-breaking heat waves that have scorched the southwestern
United States and northern Mexico, China and southern Europe were made
dramatically more likely due to human-caused climate change, researchers
report July 25 in a study from the World Weather Attribution network.
“This is absolutely not a surprise,” climate scientist Friederike Otto of
Imperial College London said at a July 24 news briefing. But “while the weather
is changing as expected, how much it hurts us is larger than expected.”
These intense and at times deadly heat waves are occurring as high-pressure
systems stall across the Northern Hemisphere, creating barely budging heat
domes (SN: 7/19/23). Phoenix, for example, has reached at least 43.3° C
(110° Fahrenheit) every day for more than three weeks.
Otto and her colleagues used computers to simulate Earth’s climate,
with and without human-caused climate change, to assess how likely the
recent heat waves would have been under different climate conditions.
In a world without climate change, they found, the recent extreme
heat in China would be expected roughly once every 250 years. Now,
it’s a once-in-five-years phenomenon, or 50 times more likely to occur.
Meanwhile the extreme heat waves in southern Europe and North America,
which would have been virtually impossible without climate change,
are now likely to occur once every 10 years and 15 years, respectively.
Should climate warming reach 2 degrees Celsius above preindustrial levels,
these events could occur every two to five years, the simulations showed.
We’ve already warmed by at least 1.1 degrees C since then (SN: 12/22/22).
Though it’s still too early to pin down the human toll of these extreme events,
hundreds of deaths have already been reported from regions around the world,
and power shortage concerns grow as the demand for cooling surges.
“The risks are rising faster than we are adapting,” Otto said.
“We are much more vulnerable than we might have liked to believe in the past.”
Provided by the IKCEST Disaster Risk Reduction Knowledge Service System