White Rooftops Could Slow Climate Change

A new study released Tuesday concludes that if the rooftops of the world's 100 largest cities were painted white it could significantly cool the atmosphere.

1 minute read

September 11, 2008, 7:00 AM PDT

By Tim Halbur


"According to Hashem Akbari, a physicist with the Lawrence Berkeley National Laboratory, a 1,000-square-foot roof -- the average size on an American home -- offsets 10 metric tons of planet-heating carbon dioxide emissions in the atmosphere if dark-colored shingles or coatings are replaced with white material.

Globally, roofs account for 25% of the surface of most cities, and pavement accounts for about 35%. If all were switched to reflective material in 100 major urban areas, it would offset 44 metric gigatons of greenhouse gases, which have been trapping heat in the atmosphere and altering the climate on a potentially dangerous scale.

That is more than all the countries on Earth emit in a single year. And, with global climate negotiators focused on limiting a rapid increase in emissions, installing cool roofs and pavements would offset more than 10 years of emissions growth, even without slashing industrial pollution."

Wednesday, September 10, 2008 in The Los Angeles Times

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

"Altadena - Not For Sale" yard sign in front of burned down house after Eaton Fire in Altadena, California in January 2025.

Half of Post-Fire Altadena Home Sales Were to Corporations

Large investors are quietly buying up dozens of properties in Altadena, California, where a devastating wildfire destroyed more than 6,000 homes in January.

July 7 - Dwell

Dense multistory residential buildings in hilly San Francisco, California.

Opinion: What San Francisco’s Proposed ‘Family Zoning’ Could Really Mean

Mayor Lurie is using ‘family zoning’ to encourage denser development and upzoning — but could the concept actually foster community and more human-scale public spaces?

July 7 - The San Francisco Standard

Blue self-driving Ford Transit van shuttle in Jacksonville, Florida.

Jacksonville Launches First Autonomous Transit Shuttle in US

A fleet of 14 fully autonomous vehicles will serve a 3.5-mile downtown Jacksonville route with 12 stops.

July 7 - Smart Cities Dive

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.

Associate/Senior Planner

Gallatin County Department of Planning & Community Development

Senior Planner

Heyer Gruel & Associates PA