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Marissa Nofal
14 April 2015
Not Another Global Warming Debate
We all know the feeling1. You tip your sunglasses off their perch from atop your head
and they fall to their resting place on the bridge of your nose. At that moment, you lean into the
door handle and the barrier to the outside world swings open letting in a flood of mid-August
sunshine. An equally intense wall of stagnant air hits you in the face as you step out the door
onto the concrete pavement that seems to scorch your feet through the soles of your rubber-based
Converse. The air smells like Sonoran desert dirt and its dryness burns your nostrils with every
deep, laborious inhalation. Almost immediately, you can feel little globules of sweat gather
along your hairline. As you cruise down the street, you become intensely aware of your
discomfort and it feels like even the buildings that wall you in are emitting an unnecessary
amount of ultraviolet radiation to every inch of your body. This is an Arizona summer.
Even natives of this Southwestern state find the heat unbearable. Despite all the
precautions and years of experience living in this colossal, open-air oven, no one can seem to
grow accustomed to the sweltering temperatures; it seems like it just keeps getting hotter.
Maybe that observation is true; maybe Arizona’s climate is changing locally. Most people
attribute rising temperatures and change in climate to global warming- a debate that seems to
perpetually nip at our heels. The truth of the matter is that global warming is such a general
term; it encompasses a myriad of interwoven topics that are in constant friction with each other,
which makes it difficult for people to agree on one solution. However, if the scope of the
discussion is narrowed, one can find a more specific, equally critical topic affecting the overall
“We” meaning those of us that have found themselves in Arizona during any portion of the
period between May and September. For those of you that have not, count your blessings.
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climate change debate. In fact, in layman’s terms, one can think of this focus as global warming
on a much smaller scale: local warming, so to speak. It takes place in burgeoning metropolitan
areas and is referred to as the urban heat island affect. Like many other metropolitan cities
around the world, Phoenix is an epicenter of local climate change resulting from rapid increases
in urbanization over the past century. However, unlike other metropolitan cities, Phoenix has the
most potential to reverse the effects of its urban heat island and is already taking decisive steps to
alter its looming fate. It can serve as a model to other metropolitan areas that are suffering from
the same human-induced heating phenomenon: if Phoenix can achieve its heat island goals, then
so can other cities.
Part I: The Science
According to geographical and urban planning research conducted by a group of
researchers from Arizona State University in Tempe, the Phoenix metro area has grown
exponentially in population and physical size from about 1950 to the present day and shows no
sign of stopping in the immediate future. To put this in perspective, the early fifties in Phoenix
saw a population of less than half a million. Today, in 2015, Phoenix is home to over four
million residents.
With great growth, comes great responsibility. Unfortunately, Phoenix’s astounding
development has been accompanied by a certain adverse affect known as an urban heat island.
Alterations to the natural landscape due to the establishment of infrastructure- buildings, roads,
bridges, etc.- have resulted in changes in climate and weather patterns. The United States
Environmental Protection Agency states that “these changes cause urban regions to become
warmer than their rural surroundings, forming an ‘island’ of higher temperatures in the
landscape.” In a USA Today article, reporter Lindsay Friedman stated that Phoenix had the
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hottest summer temperatures compared to every other city in the United States (Friedman). With
the passage time, there has been a great increase in temperature highs in the Phoenix metro area.
According to the National Weather Service’s weather archive, Phoenix’s highest recorded July
temperatures around the turn of the twentieth century ranged, on average, between 100 and 103
degrees Fahrenheit. In comparison, the last decade of July highs yields temperatures ranging
from 104 to 109 degrees Fahrenheit. Evidently, something is changing and scientists attribute
the cause of such change to the rapid urban development and the abundance of infrastructure
(National Weather Service).
Anyone who drives a gasoline-burning vehicle is contributing to the emission of
greenhouse gases into the air and to the smog that lies in a haze over the most congested part of
the city. If you view downtown Phoenix from the summit of Squaw Peak, the sky reveals an
ombré pattern in the sky: the rich baby blue of the cloudless expanse fades into a grimy, brown
fog that lazily hovers above the tops of the buildings and curls itself around the glistening glass
panes of Chase Tower- a forty-story skyscraper in the heart of the city. Smog and greenhouse
gas emissions are blamed for higher temperatures (as they are heat-trapping particles) as well
decreased air quality.
Anyone who cranks up the air conditioning in the summertime to compensate for the loss
of internal building temperatures (due to poor or hastily installed insulation materials) is a
contributor to the heat island effect: pollutants are released into the air resulting from an effort to
supply the energy overload required by steep sir conditioning usage. I am guilty of polluting the
environment: from gasoline to energy waste to other such greenhouse gas emissions. The key,
however, is consumption in moderation and decreasing expenditure wherever possible.
Part II: The Doomsayers
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There is an extreme thinking that Phoenix, along with other urban areas, is doomed, and
has reached a point of no return, will never get back what it once had, etc. In 2009, Jonathan
Overpeck, a climate change scientist at the University of Arizona stated that “temperatures could
regularly hit the 130s in Phoenix by the second half of this century due to human-caused climate
change.” The reason for the rapid increase in temperature and other severe weather patterns
would result from the Valley’s reservoirs and other water resources running dry. Once the water
supply runs dry for one year, “our state is dead,” added Overpeck (Stern 5).
However, the truth is that Arizona has put necessary measures in place to ensure that
grave situations such as perpetual drought do not occur. For example, the state of Arizona must
be capable of proving that its water supply designs can last an entire century before the state can
be authorized to construct it. Water scarcity will always be a principal concern in Arizona
considering that the vast majority of the landscape is, in fact, a desert. What people should not
forget is the countless number of ways of obtaining and storing water. Take the Central Arizona
Project canal: it supplies forty percent of Arizona’s population with fresh water. The Roosevelt
Dam, Salt River Project’s efforts, aquifers, the Colorado River- the list of potential solutions
goes on. If all else fails, there are back-up plans already in motion that store freshwater in
underground water-banking programs. And if that still is not enough for the doomsayers to
accept, maybe they will understand that the technology for ocean water desalination and
transportation is here and ready for use in the unlikely event Phoenix will require its use (Stern
5).
In an article by Ray Stern for the Phoenix New Times, Stern quotes Dave Roberts, an
executive manager for Salt River Project’s (SRP) water-rights and contracts department:
“‘Phoenix is the most sustainable’ among Southwest cities because of advanced planning and
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conservation efforts” (5). Since the dawn of Phoenix’s time, its residents have been wise in
choosing and using their water stores and continue to consume their available resources wisely
into the present day. “Per-capita water usage by Valley residents has decreased at least 20
percent since 1990 because of public awareness and such technology as water-efficient toilets”
(5). Simply by spreading the word and educating desert-dwellers about conservation and
rationing of limited supplies, awareness has grown and has had a measurable impact on the
overall sustainability movement.
Part III: The Potential
With all this in mind, how does Phoenix stack up to other American cities experiencing
similar issues? Climate Central, a research organization based in New Jersey, conducted a study
on urban heat islands over the past decade and released a list of the top ten cities in the U.S. with
the hottest summer temperatures compared to their rural counterparts. Cities like Las Vegas,
Albuquerque, and Denver topped the list as the three highest-ranking cities. Even though
Phoenix, Arizona was part of the study, it did not make the top ten. However, that does not
mean the problem is nonexistent. The same study concluded that Phoenix has an average of five
more days of temperatures above ninety-five degrees in the summertime. It also found that parts
of the metro area have reached temperatures up to twenty-one degrees hotter than the
temperatures of surrounding rural areas (Climate Central).
Nevertheless, the city of Phoenix is taking great strides toward mitigating the effects of
our urban heat island. There are two main initiatives that are heavily advocated for in the local
government and community: cool roofs and urban forestry. The cool roofs campaign has been
tested in other large cities and is already being pushed into action in Phoenix. The National
Aeronautics and Space Administration (NASA) has been working closely with the city of New
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York City on projects to reduce the effects of their urban heat problem. One of the most cost
efficient and environmentally effective projects that NASA supports in New York City is the
altering of roof colors- from black roofs to white. Such “cool roofs” as they have been coined,
reflect light and therefore absorb less heat to keep the internal building temperature more
constant, and requiring less air conditioning usage (Dunbar). Columbia University research
scientist Stuart Gaffin2 reported in his study on cool roofs in New York City that with the
pervasive implementation of white roofs, the city’s summer temperatures could be reduced by
between five and seven degrees Fahrenheit (Gaffin).
According to Joe Gibbs, City of Phoenix Environmental Program Manager, Phoenix
received a $65,000 Bloomberg Philanthropies Cities of Service Grant in early 2014 to use toward
covering 70,000 square feet of Phoenix rooftops with cool roof coating. An assessment of the
projects effectiveness from a year before the installation of cool roof coating to a year after the
installation saw, on average, a thirty percent energy use reduction within each building with the
coating. By conserving the internal temperature of the building using the cool roof coating, the
buildings’ air conditioning systems ran less and, in turn, reduced energy use and pollutants
released into the atmosphere that otherwise would have resulted from wasting more energy to
cool the building (1).
The cool roof campaign, however, must be utilized in tandem with the urban forestry
campaigns in order to attain the best results for Phoenix’s urban heat mitigation. The logic
behind urban forestry is explained in an article in The State Press in which Richard Adkins, the
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Gaffin coined the catchy new phrase “bright is the new black”. Black tar and asphalt roofs
were initially used because they make sense architecturally: tar and asphalt are waterproof and
are convenient to install on top of aesthetically pleasing, yet strange roof geometries. Now, with
environmentalists crawling out of the woodwork, white roofs make more sense from the
viewpoint of curbing the urban heat islands and local climate change (Gaffin).
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Forestry Director for the City of Phoenix, is quoted. Adkins explains that heat is absorbed by
man-made materials like concrete and is reflected back out into the environment. Plants work
the opposite way: they do not absorb heat. Instead, they dissipate heat and provide much cooler
shade beneath their leafy branches. Adkins’ goal is “to reach 25 percent urban tree shade
coverage before 2030” (The State Press).
The Phoenix Cool Roofs and the Tree and Shade Master Plan are Phoenix’s dynamic duo
for reducing the urban heat island effect. In a study conducted by the Center for Integrated
Solutions to Climate Change at ASU, it was concluded that at their completion, these two
programs should lower temperatures in the city by approximately 4.3 degrees Fahrenheit. An
assessment of the efficacy of the two agendas yielded astonishing results in the residential
context as well. In addition to the projected benefits in the urban center, a Phoenix neighborhood
with virtually no tree shade or vegetation “could lead to a 7.9 degree cooling effect” if a twentyfive percent increase in tree canopy was installed (The State Press).
Such programs are only the start to a cooler future in the Valley of the Sun. As can be
seen, Phoenix has the most potential to alter its situation- it’s in the city’s name3. We have not
been burned to ashes, but even so we can overcome our challenges as if rising from the almostashes that symbolize our present condition. Urban heat islands are not sustainable ways of life,
yet neither is an earth with over seven billion people relying on its natural resources and
expecting to live first-world lifestyles. Rising temperatures are the planet’s way of keeping us
honest and reminding us of our mortality. We cannot, as a human race, abuse the privilege of
life that has been bestowed upon us. With that in mind, we have realized our wrongs as people3
Phoenix was named by Darrel Duppa, a farmer who migrated to the territory in the mid-1800s.
He was enamored with Greek mythology and likened the territory’s history to the mythical bird
that rose from its ashes just like he hoped Phoenix would do after the Hohokam Indians
mysteriously abandoned the territory sometime in 1450 (Kogan).
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that we have mistreated our home. We know that we have created intense temperature changes,
but we also know that we can fix the things we have broken to improve the health of our people,
the health of our cities, and the health of our planet.
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Works Cited
Dunbar, Brian. "Bright Is The New Black: New York Roofs Go Cool." NASA. NASA, 7 Mar.
2012. Web. 6 Apr. 2015.
Friedman, Lindsay. "Top 10 Coolest and Hottest Summer Cities in USA." USA Today. Gannett,
27 July 2013. Web. 7 Apr. 2015.
Gaffin, Stuart R. "Bright Is the New Black—multi-year Performance of High-albedo Roofs in an
Urban Climate." Environmental Research Letters. IOP Science, 7 Mar. 2012. Web. 7
Apr. 2015.
"Growing Phoenix's Urban Forest Offers Cooling Potential." ACTrees. Arizona State University,
23 Sept. 2014. Web. 10 Apr. 2015.
"Heat Islands Cooking U.S. Cities." Hot and Getting Hotter. Climate Central, 20 Aug. 2014.
Web. 8 Apr. 2015.
Kogan, Jeff. "How Did Phoenix, Arizona Get Its Name." Examiner. Examiner.com, 14 Nov.
2009. Web. 14 Apr. 2015.
"Maximum Temperatures: Phoenix, Arizona." National Weather Service Forecast Office.
Weather.gov, 2014. Web. 7 Apr. 2015.
Phillips, Meagann. "Phoenix Takes Successful Steps to Lower City Temperatures." The State
Press. The State Press Arizona State University, 10 May 2014. Web. 6 Apr. 2015.
Stern, Ray. "Claims That Metro Phoenix Is Doomed Because of Climate Change Are
Exaggerated." Phoenix New Times News. Phoenix New Times, 19 Dec. 2013. Web. 17
Apr. 2015.