In summer of apocalyptic weather, concerns emerge over climate science blind spot

The rapid succession of precedent-shattering extreme weather events in North America and Europe this summer is prompting some scientists to question whether climate extremes are worsening faster than expected.

Why it matters: Extreme weather events are the deadliest, most expensive and immediate manifestations of climate change. Any miscalculations in how severe these events may become, from wildfires to heat waves and heavy rainfall, could make communities more vulnerable.

Driving the news: The West is roasting this summer, with heat records falling seemingly every day. Forests from Washington State to Montana to California are burning amid the worst drought conditions of the 21st century.

  • Authorities in Germany, Belgium and the Netherlands are still searching for victims of a devastating flood event that killed at least 180.

The big picture: The discussions and studies under way focus on just how unusual each of the recent extreme events have been, and whether current advanced computer models and statistical techniques can properly anticipate them beforehand.

  • Another set of questions revolves around scientists” ability to evaluate these events” rarity as well as causes in hindsight.
  • For example, the Pacific Northwest heat wave in late June into early July, which sent temperatures soaring to 116°F in Portland and 108°F in Seattle and 121°F in British Columbia, was so far from the norm for these areas that it’s causing experts to reevaluate what’s possible.

The intrigue: Axios spoke to nine leading scientists involved in extreme event research for this report. The Pacific Northwest heat wave is being viewed with more suspicion than the European floods as a possible indicator of something new and more dangerous that researchers have missed: a climate science blind spot.

  • For example, Andrew Dessler, a climate scientist at Texas A&M University, said he is no longer sure if climate models are accurately capturing how global warming is playing out when it comes to regional extremes specifically.
  • «If you’d asked me this three months ago, I would have said “models are doing fine,'» he said. «But this last string of disasters has really shaken my confidence in the models” predictions of regional extremes,» he said.
  • «Perhaps we’ve just been very unlucky, but I think this is an open scientific question,» he said.

Zoom in: Some scientists, such as Michael Mann of Penn State and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany, have shown that even the most up-to-date climate models fail to capture one of the main mechanisms that’s contributing to some of these extremes — a phenomena known as «planetary wave resonance

  • Such weather patterns feature stuck, sharply undulating jet stream patterns, like a meandering river of air at high altitudes, which can lock weather systems in place for long periods. This type of weather pattern existed across the Northern Hemisphere in the run-up to and during the Pacific Northwest heat wave.
  • «We can either assume that the [Pacific Northwest heat] event was a remarkable fluke, or that the models are still not capturing the relevant processes behind these events,» Mann told Axios. «Occam’s razor, in my assessment, supports the latter of these two possibilities.»
  • Meanwhile, Michael Wehner, who studies extreme events at Lawrence Berkeley National Laboratory, said part of the problem may be the tendency for climate scientists to be overly conservative in their «projection and attribution statements,» lest they be labeled alarmist. That may soon change, he said.

Of note: Society’s vulnerability to extreme events is to some extent independent of whether climate scientists are missing a new dynamic in heat waves or heavy rain events.

  • Friederike Otto, a climatologist at the University of Oxford, told Axios the extreme weather events in Europe and the Pacific Northwest were exactly the types that scientists had been warning would become more likely and intense due to human-caused climate change.
  • Policy makers should act to improve public warning systems, she said. Failures of the warning network in Germany may have contributed to the high flooding-related death toll there.

The bottom line: Philip Duffy, the executive director of the Woodwell Climate Research Center, told Axios that any faster deterioration of extreme weather events «would only reinforce the message that current actions are not commensurate with the threat we face.»

  • «We already know what we need to do: initiate rapid decarbonization, remove CO2 from the atmosphere, and improve resilience to future extreme events,» he said. «The severity of recent weather-related events only underscores the urgency of this message.»

Πηγή: axios.com

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