Louisville Magazine

AUG 2013

Louisville Magazine is Louisville's city magazine, covering Louisville people, lifestyles, politics, sports, restaurants, entertainment and homes. Includes a monthly calendar of events.

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O n a sunny May morning at Louisville Magazine, my weather app tells me that the outside temperature is 80 degrees and rising. An ofce phone is wedged between my ear and shoulder as I jot down notes from a self-described "geeky academic." Glancing through the open blinds, I see a couple stroll by on Muhammad Ali Boulevard, carrying a black rain umbrella (their only respite from the sun, apart from the occasional building shadow). I'm almost envious of their warmth, as I've borrowed a sweater from a co-worker to fend of the AC's goose bump-inducing chill. A parking lot away, two measly trees hug the sides of a parking garage. Tey register a trace of breeze. Later, when I leave work, the corner of Muhammad Ali and Second Street is stifing. By the time I make it to my car, which has boxed in a workday's worth of heat, my thawed-to-sweltering bones crave another cool blast. Te mercury has climbed to 86 degrees and we're not even in summer yet. "It's brutal," says Patrick Piuma, director of downtown's Urban Design Studio, which works on solving real-world problems for the city. "It's a detriment to have people out on the street, doing things. A hundred degrees and it's beating down and you're in the concrete environment. Not everybody wants to walk around in that." Brian Stone, the geeky academic and director of Georgia Tech's Urban Climate Lab, is familiar with this scorching scene. He studies the relationship between the urban heat-island efect (in which the city, with its concrete structures, stays hotter than its surrounding vegetative areas) and the city's tree canopy. Despite the handful of LEED-certifed developments, despite TARC's electric, hybrid and clean-diesel buses, despite the promise of the 100-mile Louisville Loop trail system, despite those nifty, solar-powered, compactable trash and recycling bins downtown, Louisville has become less green in the most literal sense: Its tree canopy is at an embarrassingly sparse level, and not just downtown. According to Stone, who has written a book titled Te City and the Coming Climate: Climate Change in the Places We Live, trees cover 27 percent of our metropolitan area (including our prided parks), as determined by satellite photography — about 13 points lower than the average for cities in our region. Downtown — resembling desert proportions in some spots — is a weak 10 percent. (A comparable area in Cincinnati is 20 percent; Atlanta, 45 percent.) Of course, certain areas of town are leafer than others. Our parks are lush, and several neighborhoods maintain mature tree canopies. But Jack Wojciechowski, who's standing under an umbrella on the corner of Seventh and Main streets selling Italian ice on the frst 94-degree day of the season, will tell you that where he is, natural shade's lacking. When I comment on the weather, he ofers me a cup of the lemon favor. He says his plugged-in Cyclone fan keeps him cool, but then adds, "I would love a big, giant oak tree here." Te exchange leaves me with a pink forehead, a sweat-seeped shirt and a brain freeze. Tis roasting bit of Main Street isn't even the most ofensive of treeless areas. Entire blocks of Jeferson Street, Fifth Street and Broadway (among others) are void of trees. Some strips display rows of fowerpots, which are cute at best. of days in the 100s, and those are very unpleasant. In 20 or 30 years, those will be half the summer." Unpleasant doesn't begin to describe heat's dangers. "Heat-related deaths kill more people in the U.S. than all other catastrophic weather events combined," says Stone, who gave a presentation to the city's Tree Advisory Commission last summer. According to a Natural Resources Defense Council brief from May of last year, among the nation's 40 largest cities, Louisville will have the highest number of heat-related deaths through 2099, at about 19,000. (For comparison, it's estimated that Jacksonville, Fla., will reach 8,000; New Orleans, 1,500. Tis stark diference, Stone says, is a result of Louisville's rate of temperature increase combined with our inability to quickly acclimate to According to Stone's fndings, among the 50 largest U.S. cities, we're heating up the fastest — 1.67 degrees every decade since 1961. Wojciechowski, who says he takes breaks in a shaded courtyard nearby, can tell you about trees' cooling efects. So can the research organizations that study urban climate. According to Stone's fndings, among the 50 largest U.S. cities, we're heating up the fastest — 1.67 degrees every decade since 1961. "Louisville is not only number one; it's double the second, which is Phoenix," he says. Te researcher frst blames our heat waves on the oppressive air that comes through the Ohio River Valley. But his main concern is the heat pattern resulting from our meager tree canopy. Te problem begins when we cut down trees and trade vegetation for development, with the I-264 corridor providing a good example. So not only are the trees and soil gone, but often they're replaced by dark roofs and asphalt roadbeds and parking lots that absorb solar radiation and cook up the city. We then fnd ourselves in a vicious cycle, cranking up air conditioners, which alone elevate outside temperatures through heat transfer. In the recently published book Walkable City, author Jef Speck cites a U.S. Department of Agriculture fnding that "the cooling impact of a single healthy tree is equivalent to 10 room-size air conditioners operating 24 hours a day." Tree-neglecting land use in the U.S., Stone says, accounts for 50 percent of the global warming that has occurred since 1950, and he says that Louisville's four-yearold climate action plan to reduce carbon emissions is critical, but won't fx the heat problem. "Right now, Louisville has a handful the warm season from cold winters.) "It's an underestimated threat," Stone says. "It's familiar; it happens slowly, mostly to older people. It tends to be discounted." Of course, the authors of the NRDC brief note, these predictions are made based on us doing "business as usual," and don't account for what we can do to cool the city down: increase refective surfaces (green roofs or even white roofs — just not radiation-absorbing dark roofs) and plant trees. Besides the cooling that shade provides, evapotranspiration, in which trees emit water vapor into the atmosphere, refects the sun's rays. According to the EPA website, the shadeevapotranspiration combination can reduce peak summer temperatures by 2 to 9 degrees. Stone says that a thriving tree canopy (for downtown Louisville that means 30 percent more coverage) is more infuential than any other environmentally proactive measure that we have at our 21st-century fngertips. I 'm walking down Cherokee Road (thriving tree canopy, indeed) on a clear but muggy day in mid-June, looking for a crew of tree trimmers I'm supposed to meet. Pockets of sun and shade alternate as I follow the hum of yard work — a sound almost synonymous with the start of summer. Down an alley is a white utility truck, its deep bed flled with tree debris. Two men from Limbwalker, a local tree- and lawn-care company, are fnishing up a job for longtime resident Sharon Hardy. Corey 8.13 LOUISVILLE MAGAZINE 45

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