Page 28 - aruba-today-20180728

A28 SCIENCE
Saturday 28 July 2018
Urban island effect' compounds Phoenix's sweltering heat

By ANITA SNOW subcommittee to study the
Associated Press heat island problem and
PHOENIX (AP) — When make recommendations,
temperatures soar as they and vowed to plant 3,000
have this week in down- new trees this year. Many
town Phoenix, homeless people associate Phoenix
people ride the air-condi- with cactus, but acacia,
tioned light rail to avoid a blue palo verde, ironwood,
heat so brutal it killed 155 desert willow and other
people in the city and sur- trees thrive here.
rounding areas last year. Aimee Esposito, executive
An occasional siren wails director of non-govern-
as paramedics rush to help mental Trees Matter, said
people sick from the heat. her Phoenix organization
Already devilishly hot for this year plans to give 5,000
being in the Sonoran des- small trees to residents
ert, Arizona's largest city across the area's Valley of
is also an "urban heat is- the Sun, and will plant more
land," a phenomenon that at schools through educa-
pushes up temperatures tional programs.
in areas covered in heat- Matt Grubisich, director of
retaining asphalt and con- operations and urban for-
crete. Forecasters said the In this Monday, July 23, 2018 photo, heat ripples blur the downtown skyline as a jet lands in estry for the nonprofit Texas
high for Phoenix had risen Phoenix, Ariz., as temperatures exceed 100 degrees in the morning hours. Trees Foundation in Dallas,
to 111 degrees (44 Celsius) Associated Press said planting trees is the
by midafternoon Thursday easiest and most effective
and was not expected to trees to provide shade and gether. flung as Cairo, Mumbai, action to ease urban heat.
hit Wednesday's record evaporative cooling that While the heat increases Johannesburg, Mexico City He said his group plants
high for the day of 116. can bring down tempera- energy consumption and and Nanjing, China, the 2,500 trees such as oak,
Phoenix officials say they tures. air pollution, authorities in heat island effect can add elm, pecan and ash annu-
are tackling urban warm- "We are working against Phoenix, the hottest of the more than 10 degrees Fahr- ally. Louisville has planted
ing, monitoring downtown a pronounced warming three cities, worry most enheit to nighttime tem- some 10,000 trees over the
temperatures, planting trend in large cities, and so about health problems like peratures, climate scientists past three years — includ-
thousands of trees and it will require a substantial heat stroke or heat exhaus- say. ing maples, oaks, elms and
capturing rainwater to cool resurfacing of urban en- tion. So far this year, five Forecasts now take into Kentucky coffee trees —
off public spaces. vironments simply to slow people have died in Mari- consideration the heat is- and sometimes pairs with
Elsewhere, Chicago main- the rate of warming," Stone copa County from heat- land, which in the case of nonprofit groups to give
tains more than 500,000 said. associated causes, and Phoenix stretches some away trees for smaller ar-
trees to offset rising tem- He said the heat island ef- another 34 cases are being 25 miles (40 kilometers) eas, such as dogwoods,
peratures and is a national fect prevents a city from investigated, public health out from the city's airport, said city sustainability offi-
leader among cities for so- peeling off the day's fur- officials said. National Weather Service cer Maria Koetter.
called green roofs covered nace-like heat after the sun "If similar numbers of people forecaster Marvin Percha "I really think the com-
with vegetation. Los Ange- sets, driving up tempera- died from any other type of said. munity is getting the mes-
les adopted an ordinance tures over time. His team's weather event, "it would To show the difference the sage about trees," Koetter
in 2014 to require reflective research shows Phoenix be considered a national effect can make, he noted said. "There's usually a line
"cool roofs" for new homes temperatures rising nearly 1 disaster," noted Phoenix that in June 2017 the night- around the block during
including rentals, while Se- degree per decade, con- sustainability officer Mark time low at Arizona State the giveaways."
attle is working to restore sistently placing it along- Hartman. University's grassy cam- Koetter said Louisville was
the city's forested park- side Dallas and Louisville, The danger is especially pus in Tempe was just 69 the first major city to com-
lands. Kentucky, as some of the acute for people like the degrees (21 Celsius). But mission a heat manage-
But climate specialists like fastest-warming U.S. cities. homeless and elderly. the nighttime low just 5 ½ ment study, which was
Brian Stone, who runs the He said Phoenix is warming An unusual heat wave in miles (9 kilometers) away done by Stone's climate
Georgia Institute of Tech- at three times the rate of France in 2003 killed nearly at Phoenix's Sky Harbor In- lab. It now offers $2,000 re-
nology's Urban Climate the planet as a whole. 15,000 people, mostly old ternational Airport, where bates to homeowners for
Lab, said more is needed. Stone noted the heat is- people left by vacationing expanses of asphalt cover cool roofs.
In urban heat islands, solar land effect is caused by relatives in homes without former farm fields, was 81 Stone said in some cities,
radiation and hot air from local land use and energy air conditioning as temper- degrees (27 degrees Cel- hundreds of thousands of
vehicles and buildings get decisions and is separate atures soared above 100 sius). trees would be needed to
trapped between high- from global warming, but (37 Celsius) degrees. Phoenix officials recently fully counter the heat island
rises. There aren't enough said the two often work to- Long noted in cities as far created a tree and shade effect.
In Phoenix, Hartman, the
sustainability officer, said
the city is also looking at
using lighter-colored as-
phalt for streets. "A palette
of solutions like this is nec-
essary, especially planting
shade trees with walkable
corridors," said David Sailor,
director of Arizona State
University's Urban Climate
Research Center.q