Fighting smog with trees and other urban-cooling tactics; say what?!

Cities radiate summertime heat. Fresno, California is one of those cities, apparently.

Bike-diamond-lane[1]“It’s a fight against the phenomenon called the urban heat island. Cities become heat islands as they trap energy from the sun in asphalt, rooftops and buildings, particularly in places as sunny and warm as Fresno or other [San Joaquin] Valley cities,” wrote a The Fresno Bee environmental reporter Mark Grossi in “Valley air officials aim to cool down decades-old smog problem.”

“Drive from downtown Fresno into the surrounding farmland on most any summer day. Feel the temperature drop several degrees. Streets and parking lots of this 112-square-mile city hold the heat long after dark.”

I’m thinking the idea here is if the high summertime temperatures could somehow be lowered through artificial means, the opportunity to somehow decrease the severity of smog is possible too, maybe even probable. A half-baked idea? Not to one group, apparently.

“It’s time to talk seriously about using trees and other city-cooling ideas, such as reflective or cool roofs, to end the San Joaquin Valley’s decades-long quest to achieve the federal one-hour ozone standard, say air-quality leaders,” Grossi wrote.

The environmental reporter, meanwhile, made reference to September 2011, a time of sweltering temps, stagnant, windless conditions, and three days where “lung-searing ozone” spiked. Those spikes exceeded the federal one-hour health standard for ozone “between 3 p.m. and 4 p.m. on weekdays when children were outside after school.

“An extensive canopy of trees over streets, parking lots and driveways might have kept ozone-cooking heat down just enough to avert those dangerous peaks, say researchers.”

Trees can also be effective mediums of pollution absorption.

Please keep in mind the Valley is experiencing drought conditions and trees do require watering. Valley water tables, from what I understand, have dropped appreciably.

In addition it is helpful to remember 57 percent of the Valley’s air pollution problem, according to the San Joaquin Valley Air Pollution Control District (SJVAPCD), is attributable to motor vehicles. “Off-road vehicles, lawn and garden equipment” and “consumer products” account for another 20 percent.

More importantly, I think, is being aware that suburban, horizontal sprawl in Valley cities continues seemingly unabated. As more square footage of Valley development is added outside city spheres of influence (city limits, essentially), more vehicle miles will be logged and by virtue of this, more pollutants emitted into the air.

How many planted trees and “cool-roof” and “cool-building” upgrades would it take to eliminate pollution in the region’s air?

SJVAPCD Executive Director and Air Pollution Control Officer Seyed Sadredin in the 2012-‘13 edition of the “Annual Report to the Community,” in “Message from the Air Pollution Control Officer” writes: “On one hand, the Valley’s geography, topography and climate conditions demand more from the Valley in the form of measures to reduce air pollution. On the other hand, the Valley’s resources and capacity to absorb regulatory costs are limited due to the region’s economic disadvantages.” The operative phrase here? “Demand more.”

Adds Grossi: “This 25,000-square-mile bowl allows dirty air to build up for days – it’s an incubator for one of the worst ozone problems in the nation.”

Bingo! And an enormous challenge to overcome.

Extremely effective pollution control measures needed

Being one of the worst places in the country for ozone, what the Valley really needs is implementation of strategies that are extremely effective at getting pollution under control.

And, furthermore, if the Valley is serious about curbing air pollution, then steps to stem the sprawl and reduce vehicle miles traveled is the place to start. What’s more, and personally, I do not believe residents are going to make a mad dash to go out and buy pollution-sequestering shade trees and/or heat-reflecting roofing and building materials en masse.

I suppose in theory the “cool-roofs” and “cool-buildings” and tree-planting ideas would work to a degree. A small-potatoes approach in trying to solve a problem of monumental proportions, wouldn’t you agree?


– Alan Kandel