Changes in Urban Landscape Can Cut Smog

According to a pair of studies by the University ofCalifornia's Lawrence Berkeley National Laboratory, doubling the number of mature trees and resurfacing dark-colored roofs and roads with heat-reflecting material in Sacramento County would almost halve

1 minute read

October 10, 2000, 7:00 AM PDT

By California 2000


Funded by the U.S. Environmental Protection Agency, the study used aerial photographs taken with infrared cameras to make temperature maps; the images showed that rooftops and blacktops were the hottest areas in a city, while parks were the coolest. Preliminary releases indicate that on a hot day, the population center of the county is 1 to 2 degrees hotter than less-developed areas. As increased temperatures speed the formation of smog, lowered temperatures would decrease the amount of smog produced. The study calculated that doubling the number of trees along with cooling roof and pavement surfaces would result in a temperature drop of 2 to 3 degrees, and cause a 6 to 8 percent drop in ozone levels.

Thanks to California 2000 Project

Tuesday, October 10, 2000 in The Sacramento Bee

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

July 2, 2025 - Diana Ionescu

White and purple sign for Slow Street in San Francisco, California with people crossing crosswalk.

San Francisco Suspends Traffic Calming Amidst Record Deaths

Citing “a challenging fiscal landscape,” the city will cease the program on the heels of 42 traffic deaths, including 24 pedestrians.

July 1, 2025 - KQED

Google street view of red brick multi-story power plant building in Pittsburgh, PA.

Defunct Pittsburgh Power Plant to Become Residential Tower

A decommissioned steam heat plant will be redeveloped into almost 100 affordable housing units.

July 4 - Pittsburgh Post-Gazette

Cyclist on protected bike lane in middle of street in Washington D.C. with Washington Monument obelisk visible in background.

Trump Prompts Restructuring of Transportation Research Board in “Unprecedented Overreach”

The TRB has eliminated more than half of its committees including those focused on climate, equity, and cities.

July 4 - Streetsblog USA

Blue and silver Amtrak train at small station.

Amtrak Rolls Out New Orleans to Alabama “Mardi Gras” Train

The new service will operate morning and evening departures between Mobile and New Orleans.

July 3 - New Orleans City Business