BOB DOUGHTY: Recently, American researchers studied ways to reduce the heat in developed areas. Scientists with the National Center for Atmospheric Research led the study. They found that painting the tops of buildings white could possibly help to cool cities and slow the effects of climate change.
The researchers used a computer model that predicted the effects of the sun’s heat. They compared the effects of black surfaces on rooftops with white roofs. They found that a city with only white rooftops could reduce the urban heat effect by thirty-three percent.
FAITH LAPIDUS: However, white roofs could have the opposite effect in winter. That is because they have a cooling effect within buildings. Cooler building temperatures in the winter could require more energy to heat the buildings.
The researchers found that some cities would be helped more than others from white roofs. This would depend on the total surface area of roofs in a city. It would also depend on the building materials used since some materials are less resistant to heat than others. The researchers say white roofs would work best in areas with warm climates and strong sunlight all year.
The team’s findings were published in the Geophysical Research Letters. America’s National Science Foundation paid for the study.
BOB DOUGHTY: Scientists say more information is needed before they can be sure that painting roofs white would help battle rising temperatures. Keith Oleson was the lead writer of the report. He says the study shows that, in theory, white roofs could be effective in reducing urban heat. However, he says, it remains to be seen if it is possible for cities to paint their roofs white.
最新
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25