Did Global Warming Destroy My Hometown?
The argument is based on simple thermodynamics: As the atmosphere warms, it holds more moisture. Since 1970, atmospheric water-vapor concentrations have increased by 4 percent. That additional moisture is fuel for storms. Day to day, Trenberth says, the effect of the increased water-vapor concentration is modest, but over time the accumulated changes result in a “magnifying effect” of 5 to 10 percent. "That's often enough to make this thunderstorm into a supercell storm, or to create new records," he said.
Trenberth has been working on this thesis since the late 1990s, and although scientists increasingly accept his argument, many are still hesitant to go as far as he does. As he told the climate writer Joseph Romm in 2010, soon after so-called thousand-year floods soaked Tennessee, the link between present-day extreme weather and well-established climatic trends “often gets underplayed by my fellow scientists.”
Determining whether climate change caused, or even worsened, an individual tornado seems to be beyond the epistemological limits of science.
But if it’s impossible to prove causation, it’s easy to see a disturbing correlation.
Climate change is happening; climate change should make many types of extreme weather more intense; extreme-weather events are already becoming more common. “The warning signs are there,” Trenberth said.
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While I was on my way back to Missouri, a friend sent a Facebook invitation to the newly created “Joplin Expatriates” group. It was an open call to a local bar for Saturday night, six days after the storm: “A Date for Destruction: Let’s Get Drunk!” I RSVP’d yes, with a note that said I expected to need a drink after seeing the destruction. “You will need five,” someone posted in reply.
Rescue crews search the rubble of a home whose structure had collapsed into its basement foundation on Bird Avenue near West 26th Street in Joplin, Missouri. Credit: BabyBare11/flickr.
By the day of the gathering, the disaster zone was festering. The air carried the smell of rotting meat, fiberglass insulation, chainsaw exhaust, burning plastic and the kind of mold that requires you to tear all the drywall out of your house. Now and then, sawdust sprayed from fresh-cut tree limbs freshened the breeze. Cleanup-crew volunteers had spent the week helping people search their destroyed homes for heirlooms before the rubble was bulldozed into a heap.
Many of those volunteers, among them my oldest and greatest friends, were at the bar. Spirits were surprisingly high. After a cursory discussion of our impressions of the damage — “Can you believe this?” “No, not really” — conversation turned to reunion-style catching up. In a way, it felt like December 23, when native sons and daughters, back in town for Christmas, sneak out to meet friends in the still-unregulated cigarette smoke of Joplin dive bars.
Even so, that week local kitchens and dining rooms had a way of turning into impromptu PTSD support groups.
One night at my dad’s, a neighbor who had spent the evening of the tornado volunteering in an emergency room described an array of horrors: an elderly woman, fully conscious, whose scalp was peeled back, exposing her skull. Another victim whose jaw had been torn halfway off. Still-living victims who emergency workers decided to black-tag, leaving them to their death so they could devote their limited time and resources to helping people who had a chance of surviving.
Another night, after dinner, my mother’s boyfriend told the story of the 12-year-old girl he met at the hospital where he was helping out. She had been in the AT&T store on Range Line when the tornado hit. During the storm, she was separated from her family. Strangers brought her to the hospital. My mother’s boyfriend stayed with her through the evening and tried to help her find her family. No one had any idea where they were. At the end of his volunteer shift, the fate of the girl’s family was still a mystery.
Within each of these horror stories was a reassuring fact: As soon as the storm hit, people scrambled to help other people. Scientists have long known that disasters have the unexpected effect of producing what sociologist Charles Fritz characterized in his 1961 study “Disasters and Mental Health: Therapeutic Principles Drawn from Disaster Studies” as “mentally healthy conditions.” Perhaps because disasters force the people living through them to focus on the present and forget their anxieties about the past and future, human beings tend to keep it together better in the middle of apocalypse than they do during the average morning commute.
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The U.S. Global Research Change Program, a federal project charged with determining how climate change will manifest itself in America, has predicted that in the coming decades the middle of the country will become hotter and drier, while the East will get wetter — and everywhere, the rain that does fall will fall more heavily. This very likely is already happening. Last year, the U.S. experienced its hottest summer in 75 years. In Joplin, as cleanup crews bulldozed homes and hauled away the debris, the temperature set new records almost daily, reaching an unnerving high of 110°F. The heat and drought were even worse to the south; Texas experienced the driest year in its history. Yet for five states in the Northeast, 2011 was the wettest year on record. Earlier in the year, Illinois, Indiana, Kentucky, Ohio, Pennsylvania and West Virginia all recorded their wettest April in 116 years. The Mississippi River flooded three million acres in three states. In September, after Hurricane Irene soaked the East Coast, topsoil from flooded farms upstate turned New York Harbor the color of Yoo-hoo. The federal Disaster Relief Fund diverted money from the Joplin relief effort to help pay for that flooding.
The meteorologist Jeff Masters wrote on his blog, “Any one of the extreme weather events of 2010” — a year whose litany of disasters reads much like last year’s — “or 2011 could have occurred naturally sometime during the past 1,000 years. But it is highly improbable that the remarkable extreme weather events of 2010 and 2011 could have all happened in such a short period of time without some powerful climate-altering force at work.”
Despite all of this, a Pew poll conducted in 2010 found that just 59 percent of Americans think there is solid evidence that the planet is warming — and that’s down from 79 percent in 2006. Only 27 percent of Americans surveyed in a different poll said climate change was their greatest environmental concern.
In 2009, 29 scientists published a paper in the journal Nature titled “A Safe Operating Space for Humanity.” In it, they listed a series of data points that will determine whether the planet remains habitable. The highest “safe” concentration of carbon dioxide in the atmosphere is 350 parts per million. The current level is 387 parts per million, and it is increasing by 2 parts per million annually. There’s no reason to believe that trend will reverse or even slow anytime soon. In 2010, as the weather became increasingly catastrophic, carbon-dioxide emissions increased by the largest percentage ever recorded.
In Joplin, a common explanation for abnormal weather is “It’s all cyclical.” These things have happened before, and they will happen again. But this explanation ignores an uncontestable fact: The world is different now than it was when the Tri-State tornado hit, or when the Great Plains became a dust bowl. We’re the ones who changed it. The process we’ve set in motion is unpredictable enough that we can’t know for certain what kind of world we’ll have in 20 or 50 or 100 years. But we won’t be able to say we couldn’t have seen it coming.
Article is courtesy of Popular Science magazine, a publication of Bonnier Corporation
Related Coverage from Climate Central:
Ruthless Tornadoes of 2011 (slideshow)
Detecting Tornadoes (video)