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Climate Change Drives Bigger, Wetter Storms -- Storms Like Florence (npr.org)

Rebecca Hersher, reporting for NPR: Hurricane Florence is moving relentlessly toward the Southeastern U.S. It's a large, powerful cyclone that will likely bring storm surge and high winds to coastal communities. But climate scientists say one of the biggest threats posed by Florence is rain. "Freshwater flooding poses the greatest risk to life," explains James Kossin, an atmospheric scientist for the National Oceanic and Atmospheric Administration and the University of Wisconsin, Madison. And Florence could cause extensive freshwater flooding for two reasons. First, Florence is moving slowly, and could all but stop when it reaches land. "The storm could be over North Carolina and traveling incredibly slowly -- on the order of just a few miles per hour," explains Kossin, who says an official from the city of Charlotte, N.C., contacted him about rainfall projections for that city.

If Florence stalls over the Southeast, it would be reminiscent of Hurricane Harvey, which spent days dumping rain on the Houston region last year. Some areas ended up with more than 60 inches, a catastrophic amount of water that shut down the entire region and resulted in at least 93 deaths. Slow-moving storms like Harvey are getting more common. A study published earlier this year by Kossin found that tropical cyclones around the world have slowed down 10 percent in the last 70 years. "We're seeing that in every ocean basin except the northern Indian Ocean," says Kossin, possibly because climate change is causing the wind currents that hurricanes ride to slow down. If Florence slows down and stalls when it hits land, it will the latest example of that trend. Kevin Trenberth of the National Center for Atmospheric Research in Boulder, Colo., says global warming also affects the size and intensity of storms like Florence.

15 of 270 comments (clear)

  1. Weatherbug says otherwise by DaMattster · · Score: 4, Interesting

    Weatherbug was pretty careful not to make the leap that Florence is a result of climate change. They had an article speculating that the reason Florence became so strong is the result of a Bermuda high which is in an unusual position for the year. The article's author felts that the blocking high was keeping Florence over warmer water so it could strengthen. Typically September hurricanes turn back out to sea.

    1. Re:Weatherbug says otherwise by hey! · · Score: 4, Insightful

      In situations like this, people want an answer (or more accurately prefer an answer) to what is in itself a meaningless question: did climate change cause this.

      The way this argument is heading is fairly typical: people lining up behind sources that support the answer they want, without asking what the question actually means.

      If I am not mistaken, the biggest destructive effects of this storm will not be to wind (which is how hurricanes are graded on the Saffir-Simpson scale) but to rainfall, and the models predict greater rainfall more unambiguously than they predict greater wind intensity.

      But even given all that, you still can't say that greenhouse gases "caused" this without getting into a dense thicket of philosophical (the Wikipedia article on causality is actually worth reading here) and geophysical technicalities.

      It's a pointless argument anyway. What we're really struggling over is whether this event means we should do something about greenhouse gas emissions. And for that causality is certainly a sufficient justification, but it's not strictly speaking necessary. It just has to be representative of the likely consequences of greenhouse gas emissions.

      --
      Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
    2. Re: Weatherbug says otherwise by c6gunner · · Score: 4, Interesting

      The problem is that everyone focuses on possible negative repercussions and ignores any which mat have been positive. If there is a 10 year lull in hurricanes, will anyone do a study to see if climate change is responsible? If such a study, by some miracle, actually gets done, will the news breathlessly report that climate change has caused a reduction in hurricanes?

    3. Re:Weatherbug says otherwise by riverat1 · · Score: 4, Informative

      I'm trying to figure this out....they're saying that global warming is going to cause this large storm to stall and dump rain?

      I mean, it is moving about 15mph or so now, and is forecast to slow to like 3-7mph once it makes landfall....and somehow this slowdown is caused by global warming?

      I mean, that is the reason they're worried about rain fall flooding.....

      The effect of global warming in the Arctic is much greater than in the tropics (see Arctic amplification). This reduces the temperature differences going south to north which is one of the major drivers of wind. So the wind has slowed down which slows down the movement of weather phenomena embedded in the wind.

    4. Re: Weatherbug says otherwise by serviscope_minor · · Score: 4, Insightful

      . If there is a 10 year lull in hurricanes, will anyone do a study to see if climate change is responsible?

      Of course they would. Your entire point is predicated on the assumption that scientists are probably shit.

      --
      SJW n. One who posts facts.
    5. Re:Weatherbug says otherwise by commodore64_love · · Score: 5, Informative

      This study shows hurricanes have NOT increased in size (contrary to the title): https://www.wunderground.com/c...

      "Tropical cyclone size does not appear to have changed significantly over the past 35 years."

      Graph (it's a flat line): https://s.w-x.co/wu/storm-size...

      --
      "I disapprove of what you say, but I will defend to the death your right to say it." - historian Evelyn Beatrice Hall
    6. Re:Weatherbug says otherwise by riverat1 · · Score: 4, Informative
  2. Movemet not due to warming by Anonymous Coward · · Score: 5, Informative

    The slow movement of Florence and possibility it stalls are not related to global warming to rather simply to the location of high pressure systems north of the storm preventing it from turning northward.

    The size of the storm could be argued to be greater due to warming, but its a statistical discussion about averages over time, not one of any particular storm.

  3. Weatherbug doesn't want to trigger rightwingers by Anonymous Coward · · Score: 5, Interesting

    And no matter if it's well supported, the politics of the rightwing does not allow AGW to be real. So lots of places won't dare to mention climate change as being the cause of ANYTHING, because the only things AGW deniers will allow climate to do is "change" in such a way that we don't do it. It sure as shit isn't allowed to DO anything. Just change.

    1. Re:Weatherbug doesn't want to trigger rightwingers by Anonymous Coward · · Score: 4, Insightful

      I remember, back in the day, we had back to back cat 4 and cat 5 hurricanes including Rita, Wilma and Katrina. Al Gore made a movie of it saying that this will happen from now on due to global warming. Then we had a 10 year span of no major hurricanes striking the east coast. We get one in a decade and all of a sudden the sky is falling again.

    2. Re:Weatherbug doesn't want to trigger rightwingers by CohibaVancouver · · Score: 5, Insightful

      You lose the argument when you refer to others as "moron deniers". If you are not intellectually honest enough to allow others to have alternate points of view

      Hey Anonymous Coward - People who believe the earth is flat or we didn't go to the moon or evolution isn't real may very well have "alternate points of view" but it doesn't mean they're not morons.

      Same deal here.

  4. Re:Scientific Consensus? by K.+S.+Kyosuke · · Score: 4, Insightful

    There's scientific consensus that life begins at conception? It was my understanding that the scientific consensus was that life had been here for billions of years and propagated through germ lines.

    --
    Ezekiel 23:20
  5. Re:If you believe the models... by ShanghaiBill · · Score: 4, Informative

    What drives storms? Temperature differences.

    This is nonsense. Hurricanes are not driven by temperature differences between the tropics and temperate regions. They are driven by vertical differences in temperature and pressure.

    Warm seas cause warm humid air near the surface. Warm air is lighter, and high humidity makes it lighter still. So it rises, creating a low pressure region, and drawing in more surface winds that pick up heat and humidity as they move to the center of the storm. When the air in the center rises, it spreads out and cools, condensing the humidity that falls as rain. The cooler dryer air then descends on the edge of the storm.

    Warmer seas cause stronger storms. Cooler water weakens the storm as it travels north, the opposite of what you are claiming.

    If the oceans were uniformly warm, would we still have hurricanes? Yes, and they would be stronger, bigger, and last longer.

  6. Re:Really? by religionofpeas · · Score: 4, Insightful

    It was never global cooling in the '70s, despite one or two magazine covers. And they weren't wrong about ozone. And they aren't wrong about global warming. We have more than enough data to be sure of that.

  7. Re:Not so sure about this claim either ..... by jeff4747 · · Score: 4, Insightful

    They say the same kinds of things. "Been through this a number of times before."

    When disaster approaches, people say things to comfort themselves. It helps when you're worried about your life being annihilated in a couple days, and there's little you can do about it.

    Also, "100-year" storms are a thing. The fact that there were "100-year" storms in the past doesn't mean much. What means something is the "100-year" storms now appear to be happening more like every 20 years.

    Wouldn't that mean it accounts for only 6 inches of extra rain from a 60 inch rainfall?

    Doesn't sound like much, does it?

    Now remember that 6 inches is over 1000 square miles. That's a hell of a lot of water.

    Now run all that water through the relatively small channels we call "rivers". That's a metric fuckton more flooding, because those 6 inches are concentrated into a relatively small area.

    A hurricane stalling overhead is an extremely bad thing.