A Journal of People report
Climate crisis is sparing no corner of the planet. Two US cities – Phoenix and Los Angeles – bear signs of the crisis and related developments. There are many things to learn about the crisis in these two cities.
A Los Angeles Times report on Phoenix said:
“This sprawling metropolis morphed in a matter of decades from a scorching desert outpost into one of the largest cities in the nation. Today, Phoenix is a horizon of asphalt, air conditioning and historic indifference to the pitfalls of putting 1.5 million people in a place that gets just 8 inches of rain a year and where the temperature routinely exceeds 100 degrees.
“Now, however, the city faces a reckoning. It is called climate change, and it is expected to further expose the glaring gap between how the city lives and what it can sustain. The future, scientists say, will be even hotter and drier, the monsoons more mercurial. Summertime highs could reach 130 degrees before the end of the century — think Death Valley, but with subdivisions.”
The report headlined “A building boom and climate change create an even hotter, drier Phoenix” said:
“Phoenix is one of many cities facing daunting predictions of what lies ahead, and most have few resources with which to prepare. Public health and economic prosperity are both at risk.”
The March 27, 2017 datelined report said:
“Phoenix has taken steps to react to climate change — expanding public transit and bike lanes, replacing municipal fleets with electric vehicles, putting low-energy bulbs in streetlights and setting goals for reducing carbon emissions.”
The report by William Yardley said:
The challenge Phoenix faces is not coming from rising seas. The challenge is different being faced by coastal cities.
According to the report, the average high in Phoenix in August now exceeds 104 degrees, but 110 is not uncommon, and the temperature has hit 120 more than once. In summer 2016, a study by Climate Central and the Weather Channel found that the average temperature in Phoenix had increased 1.12 degrees over the previous half a century. No major city saw temperatures rise more — and, of course, no major city regularly reached such scorching highs in the first place.
The report mentions further problems of the city:
“Phoenix makes its problem worse in several ways: Development has created a local ‘urban heat island effect,’ which limits natural nighttime cooling; only about 11% of the city is covered by trees, which provide essential shade; and the city’s famous sprawl creates emissions that contribute to the overall heating of the atmosphere.”
It adds:
“Water presents another challenge. On one hand, Phoenix can tell a remarkable story of steadily improving conservation: Even as the population has soared over the last half-century, the region now uses slightly less water than it did in the 1960s. It also has a formidable supply saved in an elaborate underground storage system created in the 1980s. When California went shrill with drought anxiety last year, Phoenix mostly shrugged.
“But the sources that feed the supply and the storage – primarily the Colorado and Salt rivers – are at risk of long droughts in the decades to come, according to climate forecasts.”
The LAT report quotes said Tom Buschatzke, director of the Arizona Department of Water Resources: “We don’t have as much water to put underground as we used to, and we see the handwriting on the wall that that’s going to continue.”
The problems turn serious as political questions enter into these. The report said:
“The political climate is brutal as well. Many state leaders do not accept climate science. The Republican-controlled Legislature is so resistant that it fights local action. Last year, it passed a law to prevent cities from requiring businesses to report how much energy they use, though such systems are mandatory in some cities in other states.
“Mayor Greg Stanton, a Democrat, says the city has to make its own way, and that means balancing concern with confidence. ‘If I don’t sound the appropriate level of alarm that climate change is going to impact our community and that we have to take steps to fight it, I won’t be able to get the reaction that I need to get the policies that we need to pass,’ he said. ‘At the same time, you don’t want to go too far so that you scare off investment, that you scare off business.’”
There are issues of development. The LAT report said:
“In 2015, voters approved a $32-billion transportation plan that included a substantial expansion of a light-rail system. That has helped spur a rush of apartment and condominium construction nearby, lured new tech companies and increased gentrification of an arts district called Roosevelt Row.”
According to the report, last month, the city adopted a goal to reduce its greenhouse gas emissions by 40% by 2030 from 2005 levels – after exceeding its previous goal of 15%. The city’s bike-sharing program has 12,000 registered riders and is looking to add as many as 1,000 bikes. Phoenix has a plan to expand its tree canopy, but there is little money for taking other measures, and it faces stiff competition for grants. The city was rejected last year by the Rockefeller Foundation when it sought money to hire a climate resilience officer. Phoenix’s new climate program, Resilient PHX, is staffed with two “resilience engagement coordinators,” but they were assigned to the city for temporary terms through the AmeriCorps service program, which Trump has proposed cutting. Without money for major projects, the program’s goal is to help residents help themselves, particularly those in lower-income areas. Last summer, the program enlisted a Boy Scout who needed an Eagle Scout project to organize volunteers to hand out maps to inform people where they could find free water and shade on excessively hot days. The program has also worked to expand shade in low-income areas with heavy pedestrian traffic. Last year, it planted 33 trees. Nick Roosevelt, one of the resilience coordinators, is acutely aware of the small scale of his work relative to the challenge. His great-great-grandfather President Franklin D. Roosevelt created an earlier public service organization with far more resources, the Civilian Conservation Corps. Its workers helped expand the ambitious canal system that now quenches Phoenix’s thirst. Further back in his lineage, President Theodore Roosevelt built the giant dam that made Phoenix possible in the first place. Roosevelt knows that his ancestors’ efforts to settle the Southwest helped create some of the challenges he is now trying to address. “Arguments can be made that people should not live in the desert or along the coasts,” Roosevelt said. “But people are there and what are we going to do about it?”
The report quotes two experts:
“‘My colleagues and I wonder about the future habitability of Phoenix all the time,’ said David Hondula, a climatologist who studies the impact of heat on health at Arizona State University.
“‘As we go forward in time and the impacts of climate change become more significant, cities’ resilience will become a factor of competitive advantage,’ said Cynthia McHale, who works for Ceres, a nonprofit that promotes sustainability among businesses and investors.
Scientists are exploring the benefits of planting trees, installing “cool pavement” and “cool roofs” in urban areas. Some coastal areas are mulling over major investments. In New York, multibillion-dollar sea barriers are being planned. Miami Beach is already spending hundreds of millions of dollars to raise streets and install pumps to prevent and relieve flooding. Los Angeles has taken a few measures. In Los Angeles, temperature records were shattered last summer during scorching heat waves that saw highs of 100 degrees for five days straight.
Los Angeles Mayor Eric Garcetti has pledged to reduce the average temperature in the metropolis by 3 degrees over the next 20 years.
A LAT report headlined “L.A.’s mayor wants to lower the city’s temperature. These scientists are figuring out how to do it” said: The Mayor’s goal is noble as it will reduce energy consumption and improve air quality. It may even save lives as extreme heat kills more people each year than hurricanes, floods or tornadoes.
The report by Deborah Netburn said:
“Climate models suggest that by 2050, the temperature in downtown L.A. will exceed 95 degrees 22 days per year. In 1990, only six days were that warm. The San Fernando Valley is expected to see 92 days of this extreme heat per year, compared with 54 in 1990.”
It added:
“L.A.’s heat problem is expected to worsen over the coming decades.”
The February 9, 2017 datelined report said:
“Angelenos are also contending with an additional layer of misery caused by what’s known as the ‘urban heat island effect.’ It means that cities – with their asphalt streets, dark roofs, sparse vegetation and car-clogged roads – are almost always a few degrees warmer than the more rural areas that surround them.”
It said:
“More than half of city surfaces are covered by dark pavements and dark roofs. Traditional asphalt absorbs up to 90% of the sun’s radiation. As the asphalt gets hotter, it warms the air around it, adding to the overall heat. Even after the sun goes down, that accumulated heat lingers for hours and continues to transfer warmth to the night air.”
The LAT report said:
Arash Mohegh and Mo Chen, two experts, drove across the San Fernando Valley and measured temperatures over the course of the day on June 2, 2016. They found a variability of over 20 degrees between downtown L.A. and areas of the valley like Northridge and Canoga Park. To get accurate measurements, they spend hours weaving up and down streets in their target neighborhoods. They visited the San Fernando Valley on a particularly scorching day in June. As blocky office buildings gave way to tree-lined streets with green lawns, their thermometer dropped from 102 to 100 degrees.
Matt Petersen, chief sustainability officer for the office of the mayor, said work like this will help the city identify which areas should be targeted for cooling and which strategies will work best. By 2019, he hopes to have a better idea of how realistic the goal of lowering the temperature by 3 degrees really is, as well as the best way to achieve it.
The report said:
Petersen hopes to reduce the amount of warming L.A. will experience in the future. In early July, Petersen’s team convened a group of about 20 civil servants and university scientists to determine how to bring the city’s temperature more in line with what it would have been if Los Angeles had never been developed. The city has already teamed up with USC environmental engineer George Ban-Weiss. A veteran of the Lawrence Berkeley National Laboratory’s Heat Island Group, he said there is no better place to test different ways of reducing urban heat than L.A.
One way to combat this heat sink is to replace the city’s streets and sidewalks with high-tech materials that reflect more sunlight and stay cooler during the day and at night. Some of these “cool pavements” reflect light only in the infrared part of the spectrum, which we cannot see. In the summer of 2015, the city’s Bureau of Street Surfaces tested one of these cool pavements at the Balboa Sports Complex parking lot in Encino. The new surface was approximately 11 degrees cooler than regular pavement in the mid-afternoon.
The report said:
Scientists and policymakers are also investigating “cool roofs” and their potential to reduce the overall temperature of the city. Studies have found that in Los Angeles, widespread deployment of cool roofs could reduce the city’s temperature by as much as 2 degrees Fahrenheit. But it’s unlikely that a single strategy will be the most effective option for all neighborhoods. If an area has no tree cover but lots of cool roofs, adding more cool roofs won’t be as useful as planting trees. On the other hand, if an area has lots of trees, adding reflective pavements won’t reduce temperatures because the sidewalks don’t get much sunlight anyway. Some regions of the city require more cooling than others. The biggest factor affecting temperature in the Southland is the influence of sea breezes. As those winds travel east, they pick up heat from the land and deliver it to those who live inland.
Scientists involved are modeling microclimates of areas as small as a few city blocks. After painstakingly building a computer model that included each tree and building, the researchers were able to analyze the effects of various heat mitigation strategies, comparing how it would feel if streets had more reflective surfaces, if every grassy yard were shaded by trees, and if every roof were covered in grass. They found that cool roofs and green roofs had little effect on the thermal comfort of a person walking down the street, and that putting more trees in unshaded areas was the most effective cooling strategy. However, in areas that were already shady, the most significant effect came from cool pavements.
The report raises the following questions:
“But how do you turn down the thermostat of an entire city in a warming world? And in a place as vast, sprawling and heterogeneous as Los Angeles, how do you measure success?”
The report said:
“The mayor’s plan to cool the region won’t compensate for all the effects of climate change.”
Journal of People 