Contrary to commentator Samir Ibrahim's assertions about white roofs, a number of studies have found that Baltimore homeowners would see net energy cost savings as a result of installing a cool roof ("White roofs aren't so cool," Oct. 23).
The cool roof market in the northern U.S. is more than 20 years old and continues to experience annual growth. There are billions of square feet of cool roofs installed in northern climates. Target uses white roofs on all of its stores and reports net energy savings and none of the problems Mr. Ibrahim mentions.
The devil is in the details, and Mr. Ibrahim doesn't share enough of his assumptions for us to really understand how he reaches his conclusions about Baltimore. Peer-reviewed work from Lawrence Berkeley National Laboratory does provide that transparency and does indicate energy savings here.
The Stanford paper cited by Mr. Ibrahim concludes that it is possible that cool roofs could cause some warming on a global scale. The authors acknowledge the clear regional cooling benefits and note that their global findings are uncertain and well within the error band.
That means it is hard to separate the "signal from the noise" on the global cooling impact. The paper raises some important possible impacts of large-scale cool roof deployment that is part of growing body of research done by scientists from around the world. All of that work shows more favorable global cool benefits than the Stanford paper.
It is always a good idea to work with a roofing professional when deciding what makes sense for one's roof. The benefits of cool roofs in Baltimore can mean lower energy bills and a more comfortable and healthy neighborhood.
Kurt Shickman, Washington, D.C.
The writer is executive director of the Global Cool Cities Alliance.