Every story about dramatic survival in a desert environment will include a scene where the main character, who is parched, gleefully spots water from a distance and then arrives to find it.it has disappeared. As the sunanddaytime temperatures continue torise,the protagonist becomes increasingly disoriented andthisalarmingsituationoccurs again and again.
These are more than just a movie scene.Mirages are an optical phenomenon that occurs when the sun heats a surface. This heat then radiates heat into the air above it, creating a temperature difference between the air above the ground and the air below. This contrast causes the light that is heading towards your eyesto refract as it crosses the temperature barrier. This results in a squiggly appearance that looks like water.
The puddle in distant will not (almost certainly) ever be real. But don’t lose heart. The hazy heat from the desert surface can have serious consequences for people trying to live in mirage-prone environments like Arizona. The Maricopa County Department of Public Health is set to be established in 2021. reported252 heat-related deaths have been reported, 72% of which are outside.
Scientists have known for years that asphalt and concrete paving over desert surfaces increases solar heat absorption, which is then released back into urban air at night. This tendency for urban environments to heat up faster than their natural surroundings is known as the “urban Heat Island” or the “urban heating effect.”
Scientists also know that city temperatures are not just rising due to the built environment. The effects of greenhouse gases on the atmosphere are also contributing to climate change. primarily– The burning of fossil fuels.
When it comes down to our hotter cities, the question is how much can that rising heat be attributed one source vs. other.
The role and importance of the built environment
According to the Maricopa County Housing Authority, more than 173,000 new housing units were built between 2010-2020. Latest reportAccording to the U.S. Census Bureau. Additional roads, stores, offices and roads are available to accommodate these new residents. The average annual temperature for Phoenix over the same period was as RecordedAccording to the National Weather Service, the temperature rose by approximately two degrees Fahrenheit
Phoenix is a city that 50 years ago was a tiny dot on the map. The more you build, the warmer you will be.” MateiGeorgescuProfessor of Geographical Sciences and Urban Planning, Arizona State University. He specializes in urban heat research.
Drawing on adecade of work,Georgescuestimatesthat roughly half of recentwarming in the Phoenix metro areais due to the expansion of man-made structures that absorbsolar energy. The rest is due to greenhouse gases.
The climate and urbanizationAccording to a report, population growth poses greater climate risks for metro areas. However, it also offers hope.
Georgescu and colleagues from ASU calibrated a computer modeling to determine the natural properties and fluctuations of heatwaves, temperature fluctuations, and the regional climate. They then added the built environment to the model, increasing the percentage of land covered with impermeable, manmade surfaces that retain more heat than soil and plants. They eventually had a computerized representation showing what urbanization in the sun belt could look like in 2050.
The simulation results were then compared to a climate modeling output for the same area and time period. This model did not include the built-environment, but did include greenhouse gas effects.
“Our results show that the effect on warming due to the built environment is comparable in magnitude to that of warming from greenhouse gases,” Georgescu stated.
As with any prediction about the future, the models have their limitations.
“We are not smart enough to say that warming in some neighborhood in Tempe is going to be 20% because of the built environment and 80% because of greenhouse gases. But that’s not the point. This is because one cannot ignore the urban environment when calculatingthetotalityof warming that is expected for the future.
Patrick Phelan, a professor at ASU, is also hard at work on a project which aims to address the issue of urban warming. He claims that higher temperatures cause machinery to be less efficient, which leads to worsening conditions.
He explained that thermodynamics states that engines will perform worse if they are subject to higher temperatures to remove heat from them. That means that the engines must work harder to combat climate change.
Phelan directs the ASU branch of the U.S. Department of Energy project. This project trains engineering students to assess how small and medium-sized manufacturing businesses might be ableto reduce their energy consumption and improve their machinery efficiency. The website is open to all companies. Industrial Assessment CenterVisit this website to find out more and request this service for free.
Phelan stated that while not everyone recognizes that global warming poses a problem, most people do recognize that urban heat islands pose a problem. “So what can be done about it?” One way is to encourage people to use less energy. This is one of the many ways we can encourage it.”
The changing climate’s role
Georgescu and his colleagues highlighted the problem of global warming caused by both the built environment and emissions from poorly-functioning engines. in a later studyThey split their model projections into three-hour segments.
“Withresultsnot averaging for an entire summer but for every three hours we couldsayWhenGeorgescu stated that the built environment’s effect on warming is greater during the 24-hour period of the day, relative to the effects of greenhouse gases.
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They discovered that while the built environment can prevent temperatures from falling to old lows overnight, it is the effects of higher concentrations of greenhouse gasses in the air that cause daytime temperature rises.
Georgescu stated, “The effect on increased greenhouse gas emissions is consistent throughout the 24-hour time period while the effect is greater during the evening and nighttime hour and is minimal or negligible in the daylight hours.”
This can be observed in temperature RecordingsThe first recorded record dates back to 1948 at the Phoenix Sky Harbor International Airport National Weather Servicestation. This area is perhaps the most paved in the metro and has the most modern heat-generating engines. The average annual temperature rose from 69.7°F in 1948, to 77.2°F in 2020. However, the annual minimum warmed faster, from 22°F in 1948, to 35°F in 2020.
Georgescu stated that the double influence of climate change and urban development can explain this dramatic rise in overnight lows. But any daytime increase over long periods would be due to climate changes.
It’s those climate-drivendaytime maximumsthat havehad consequences at Sky Harbor. In 1990, when daytime temperatures hit 122 degrees Fahrenheit, the airport groundedplanesbecause it had no data on how well their engines would function in those conditions.These are uncharted skies. It happened again in 2013, and again in 2017, when the NWS’s Sky Harborthermometer reached 119. Over time, the airport has grown in size and traffic.
Georgescu said, “It’s likely not going to take that long from now that SkyHarbor’s minimum temperature won’t dipbelow 100 degrees Fahrenheit.”
Sometimes the complexity of climate changeand what is behind rising average temperaturesand increasingly strange weather can feel like an optical illusion. It’s like the desert is playing tricks with your dehydrated mind. Science can often explain why phenomena occur. DoOther forceswe don’t see are real can’tYou can see how much you are.
Georgescu has one last message for those who doubt the role of climate change or greenhouse gases in rising urban temperatures:
My classes are open to all. I teach Intro To Climatology. I am serious. People should educate themselves and be open for discussion with experts in the field.
Joan Meiners, climate news reporter at The Arizona Republic (azcentral.com), is a storyteller and climate news reporter. Before becoming a journalist she earned a Ph.D.@beecyclesor email her [email protected].