Advertise Here

Deliver your message to thousands of readers every day.

Our readers are influential opinion makers - politicians, journalists and activists.

Learn more about ads.

Our latest headlines

Want more? Dive into the archives.

About Us

David Greenwald, Editor. (Contact David.)
CFC Education Foundation, Publisher. (Contact us.)

Got a news tip? Want to write a guest column?
Contact David here.

About California Progress Report.

Founded by Frank D. Russo (Publisher and Editor, 2006-08).

Books

Curbing California's Urban Heat Islands

The Temp’s Rising -
Do you live in an Urban Heat Island?
How to turn your ‘urban heat island’ into a ‘cool city’

By Loni Hancock
Chair
California State Assembly Natural Resources Committee

Every summer, sweltering heat is accompanies by elevated levels of smog and increased health risks. Inner core cities will be up to 10° hotter due to what scientists at Lawrence Berkeley National Laboratory (Berkeley Lab) have labeled the ‘urban heat island effect.’ Urban heat islands are significantly warmer than their surrounding undeveloped areas as a result of vegetation being replaced by buildings with dark colored roofs and asphalt roads that absorb heat.

Although the causes of urban heat islands are distinct from global climate change, the two phenomena are related. Urban heat islands intensify the effects of global warming in urban areas. Higher temperatures lead to increased air conditioning. Air conditioners are a significant and growing contributor to greenhouse emissions that promote global warming.

Fortunately, there are several easy and inexpensive actions that we all can take to cool cities and suburbs, such as installing cool roofs, selecting cool paints, using cool pavements and planting more trees. For these reasons I have introduced Assembly Bill 785, legislation that will result in reduced temperatures and energy use, creating a healthier and cooler atmosphere for California urban areas. Assembly Bill 785 requires contractors to comply with existing energy efficiency standards on remodeling projects and adds penalties to those who ignore energy efficiency building regulations.

The first step we can take is to install ‘cool roofs.’ Buildings with cool roofs reduce the urban heat island effect. Cool roofing material contains a highly reflective substance that reflects solar energy back out into the atmosphere and discharges stored heat rapidly. Compared to traditional roof surfaces, which can get as hot as 190° on hot summer days, cool roofs stay up to 70° cooler and discharges stored intense attic heat. The benefits of cool roofs are numerous, keeping inside temperatures – and cooling costs – down.

A second promising approach we can take is to purchase vehicles with highly reflective exterior paint colors. ‘Cool colors’ such as white, metallic silver and metallic gold reflect sunlight back into the atmosphere resulting in a cooler vehicle cabin and reduction in air conditioning, fuel and vehicle emissions – providing cleaner healthier air. Berkeley Lab, the State Air Resources Board and the State Energy Resources Conservation and Development Commission are developing highly reflective exterior paints, in colors other than white, metallic gold or metallic silver. Their continued work will offer plenty of alternatives to consumers in the near future.

Berkeley Lab has developed techniques to cool urban areas by installing and repaving roads with products which increase the reflectivity of paved surfaces. Processes which now enhance reflectivity include compressing chip seals into new asphalt and adding a white liquid to cement concrete, also known as “white topping.” Berkeley Lab continues to develop cutting edge solutions that will provide options for city and county planners which will result in overall thermal comfort to Californians.

Trees are one of the most important, simple, and effective ways to reduce urban heat islands. The detrimental heat island effects of large paved strip malls can be dramatically reduced by simply planting trees in these areas. Bringing vegetation back into our cities and into new communities will bestow beauty, shade, reduced temperatures and cleaner air upon all of us. Trees, plants and gardens are not only aesthetically pleasing they are also an inexpensive solution to achieving heat island reduction.

With a majority of Californians concerned about climate change and wanting action, we need to do these simple things that we know how to do - and do it now! California continues to experience unprecedented growth. Implementing easy and effective policies now to curtail the urban heat island effect will help us accommodate this new growth without hurting the environment. AB 785 is a simple step forward to achieve this objective, and create cooler climates.

Loni Hancock is the Chair of Assembly Natural Resources Committee and the author of AB 785 which is on Governor Schwarzenegger's desk.

Posted on September 27, 2007

Comments

Why does there have to be yet another law? If the idea has merit and majority of Californians believe its a good idea why not privately promote the idea? People are smart and will act if you can convince them its the right thing to do why force them to? For someone who promotes choice in so many other aspects of life why not here?

Posted by: sean at September 27, 2007 10:14 AM

Sean: The answer should be fairly obvious. There are societal benefits that go beyond the individual. This is the basic reason we have government, laws that require stopping at stop signs, and the like.

Posted by: Frank D. Russo at September 27, 2007 10:44 AM

There's a spray on cool coating for tile renovation with deep colors and high reflectivity from American Rooftile Coatings. MCA tile manufactures a beautiful range of cool colored clay tiles. Custom-Bilt Metals makes a range of cool colored standing seam and metal tile roofing. Elk Roofing makes a composition shingle with over 25% reflectivity. And there are a number of elastomeric white cool coatings which can be applied to existing shingles. Plus, PG&E, Edison and SMUD are all offering rebates for cool roofs.

Posted by: Chris Scruton at September 28, 2007 09:50 AM

Get Email Updates

Want the California Progress Report by email? Once a week, we'll send you the latest and greatest headlines.

Stat tracker