Per Capita Davis: A white roof is a cool roof

I don’t know how it could have happened, but somehow I missed every single one of the 100 episodes of “Bill Nye the Science Guy.” Most probably, this was because the show was aimed at children and aired during the daytime when I was at work.

I was aware of his show at the time, but he came to my attention again recently when a friend told me about Nye’s recent book, “Unstoppable,” and I took the opportunity to learn a bit about the guy and his TV program.

According to Wikipedia, the show was nominated for 23 Emmy Awards and won 19 times. That’s a pretty splendid record. But more than that, and why I am writing about him and his show, is that “studies also found that people who viewed Bill Nye regularly were better able to generate explanations and extensions of scientific concepts than non-viewers.” And, “In surveys of elementary students who watched the program, most children concluded that Nye made ‘kids like science more.’ ”

The show apparently also mirrored the strategy used by “Sesame Street”: Make the show for children, but embed a bunch of stuff that also appeals to adults, including bringing to the show a wide variety of guest stars familiar to grown-ups such as Christopher Walken, Samuel L. Jackson, Kenny G, Pat Sajak, Vanna White, Cirque du Soleil, Suzanne Somers and the Flying Karamazov Brothers. Something for everyone.

Nye has continued his efforts at science education, something that is definitely on the decline in most areas of the country. The statistic I dug out of the recesses of my memory (you judge how reliable that citation might be) is that roughly 25 percent of the high school students go on to college. Meaning that whatever the other 75 percent learn in high school is most of what they go through life with in terms of science.

Remembering that science education and the selection of textbooks are primarily at the discretion of local school boards, this largely explains, to me, how we come to be in such a mess of distrust for scientists and science.

Nye’s book is about the climate crisis. It is (mostly) very readable. It explains complex concepts with clarity, simplicity and humor. What caught my attention was his basic argument that the transition from fossil fuels to renewable resources is “unstoppable.”

There are many reasons for his optimism, including his interest in the potential of various “geoengineering” projects to help keep our planet from overheating. These projects, somewhat controversially, take a slightly different, but potentially effective tack from conventional programs for reducing greenhouse-gas emissions.

His “favorite” idea is to increase the reflectivity of buildings so that instead of absorbing incoming light from the sun they reflect more of it back into space, in effect to compensate for the loss of ice, primarily in the arctic. That ice reflects, according to his calculation, about 60 percent of incoming sunlight, as opposed to melted ice (seawater) that reflects only 10 percent.

He further calculates that painting rooftops in the United States white could cover 2 percent of our landmass, resulting in a huge counter to the loss of reflecting ice.

This may sound like a kooky idea, and maybe it is, since it requires massive cooperation from owners of homes, factories and businesses, not to mention a boatload of white paint, though his preferred approach would appear to be to require compliance, also an iffy proposition.

But, there are some big names who agree that this might be a worthwhile approach, including former Vice President Al Gore and Michael Bloomberg, who served three terms as mayor of New York City from 2002 through 2013. Together, they kicked off a “Cool Roofs” project in 2009 that, according to the program’s 2013 annual report, had “cooled and coated 2,077,537 square feet of rooftop utilizing over 1,000 volunteers.”

I like the precision of their number: not over 2 million or just under 2.1 million but 2,077,537.

Program materials at the time of launch included estimates that it would “lower roof temperatures by up to 60 degrees and indoor temperatures by 10-20 degrees on hot days. The decrease in temperature reduces the need for air-conditioning, lowering electric bills and reducing energy consumption,” potentially resulting in up to a 1-degree reduction in ambient air temperature in New York City.

According to an article in the New York Times, a 2010 study from Geophysical Research Letters basically endorsed this prediction, though at a slightly less than 1-degree level. Others disagree.

Even a luminary like Steven Chu, President Obama’s energy secretary, endorsed the idea, indicating that “if you take all the buildings and make their roofs white and if you make the pavement more of a concrete color rather than a black type of color, and you do this uniformly … it’s the equivalent of reducing the carbon emissions due to all the cars on the road for 11 years.”

On that second point, the city of Los Angeles is now experimenting with a sealant applied on top of asphalt that potentially increases reflectivity of that pavement by more than 300 percent.

Maybe the Science Guy isn’t that kooky after all.

— John Mott-Smith is a resident of Davis; his column is published on the first and third Wednesdays of each month. Send comments to johnmottsmith@comcast.net