Unexplained Heat Wave ‘Hotspots’ Are Popping Up Across the Globe
news.climate.columbia.edu
Distinct regions are seeing repeated heat waves so extreme, they cannot be explained by climate models.

Earth’s hottest recorded year was 2023, at 2.12 degrees F above the 20th-century average. This surpassed the previous record set in 2016. So far, the 10 hottest yearly average temperatures have occurred in the past decade. And, with the hottest summer and hottest single day, 2024 is on track to set yet another record.

All this may not be breaking news to everyone, but amid this upward march in average temperatures, a striking new phenomenon is emerging: distinct regions are seeing repeated heat waves that are so extreme, they fall far beyond what any model of global warming can predict or explain. A new study provides the first worldwide map of such regions, which show up on every continent except Antarctica like giant, angry skin blotches. In recent years, these heat waves have killed tens of thousands of people, withered crops and forests, and sparked devastating wildfires.

  • Onno (VK6FLAB)@lemmy.radio
    9·
    21 days ago

    Something squirrelly about this chart.

    I live in Western Australia where it shows grey areas bigger than some countries. The grey colours are presumably missing data, except that smack in the middle of those is the capital of Western Australia, Perth and several other populations centers.

    • Feline [she/her, they/them]@hexbear.netEnglish
      4·
      21 days ago

      From the paper’s caption for that figure:

      Regional trends of extreme temperatures are underestimated in climate model experiments in multiple regions globally. (A) Comparison of observed trends in tail-widening (yearly 99th percentile minus 87.5th percentile) with 49 simulations from coupled and SST-forced climate models (SI Appendix, Table S1). Observed trends are outside of the modeled range in several regions globally (dark red). Areas where the annual 87.5th percentile of Tx shows a negative trend in observations are shown in gray ~~ So I think that means tail-widening ~= more heat waves. Colored areas are where heat waves are increasing, and climate models have underestimated the observed heat waves. Gray = areas that heat waves have become less frequent~~ nevermind, I’m still confused lol

      The caption from the columbia article seems wrong:

      Regions where observed heat waves exceed trends from climate models. Boxed areas with the darkest red colors are the most extreme; lesser reds and oranges exceed models, but not by as much. Yellows roughly match models, while greens and blues are below what models would project.

      Pretty sure that’s wrong because the scale on the paper’s graphic shows a scale going from blue (0%) to dark red (100%). That means the map is much worse than what article says. Yellow is not where it “roughly match models”, it’s actually where the models underestimate by 50-75%

      • Onno (VK6FLAB)@lemmy.radio
        2·
        21 days ago

        Sorry, I deleted my comment because when I zoomed in even further, I discovered that the grey areas didn’t specifically include Perth. I tried to reinstate it.

        My original comment was:

        Something squirrelly about this chart.

        I live in Western Australia where it shows grey areas bigger than some countries. The grey colours are presumably missing data, except that smack in the middle of those is the capital of Western Australia, Perth and several other populations centers.

        I can’t link the grey to isolated, since much of the continent is sparsely populated. The lower south west of Australia has a higher population than the rest of that state, but that’s in contrast with the north west where there’s not many people as all.

    • Leeny@lemmy.ca
      4·
      21 days ago

      Missing data, or a missing prediction…since the chart is showing a difference between the two. It’s possible the model for those areas had some issue. I agree it’s worth questioning.