On Ecoblog has already been treated Global warming as an argument that color the roofs of the houses in white is a good practice to lower the temperature on the planet. Now, however, is published a study (by physical Hashem Akbari of the Lawrence Berkeley National Laboratory along with some experts at the University of California) that has provided some interesting numbers on the effectiveness of this application also include the usefulness of sidewalks. According to this research, if hypothetically the 100 biggest cities in the world installing roofs white and change the sidewalks with more reflective material, it would have a significant effect raffreddante. Let’s see why. The average percentage of area employment in the cities are very high, in fact around 25% as regards the roofs and 35% in case of sidewalks.

The data are clear: If you were to replace these materials with other reflective surfaces, it would save about 44 billion tons of greenhouse gases, or the amount of gas that all countries of the world emit in a year. The scientific explanation is that the solar radiation incident verrrebbe reflected in the form of short waves. The latter without the chance uscirebbero become so long, or heat, which on the contrary would be retained by the molecules of greenhouse gases.

This emerged from the data presented during the conference on climate change research in California. Such an application would offset more than 10 years of emissions, even without reducing those industries. Just in the American state, since 2005, has regulated that the flat structures are required to have roofs white.

One roof of about 90 square meters, the standard measure of an American house, Cut 10 tonnes of carbon dioxide emissions. Experts point to convince the UN to change the rooftops in major cities of the globe. The advantages, besides the already mentioned benefits on global warming, would be those with significant energy savings, lowering a few degrees in temperature in cities and major reduction of smog.

This is certainly a laudable position taken by scientists, although it probably would be first of all should do more analysis on the costs necessary for the implementation of a project like this.