cleaner air to turn iconic buildings green - air cleaner

The buildings of the future are bright and bright green, that is to say.
A new study of how the stone facade changed due to atmospheric changes shows that the era of gray-black buildings has passed.
In the next century, iconic limestone buildings such as the Empire State Building, the Pentagon and the Gothic cathedral in Europe and America will turn yellow and red --
Brown, even green with moss and Moss.
As pollution patterns change and wind, cities will become more colorful
The pouring rain washed away the typical black soot of the 20 th century.
In addition, legal requirements for the use of clean fuels may mean that Moss and Moss will grow more easily and some buildings will turn green.
In the 19 th and 20 th centuries, cities in Europe and the United States were dominated by dark gray and black buildings.
These are often made of cream.
Colored stone like limestone, covered with black shell of soot.
According to Peter Brimblecombe and Carlotta Grossi of the University of East Anglia, the era of air pollution that determines damage to building materials is over.
The couple recently completed an assessment of the damage to buildings in London in the last 900 s, as well as trends in the coming century-coal soot in coal --
While burning a stove is unlikely to be a problem, climate change is a problem.
They use historical climate and pollution data, combined with equations that describe how different climates and different types of pollution affect building materials.
File tax records, for example, show how much fuel has been used for centuries, which can be used to estimate historical levels of pollution.
By estimating how much black charcoal soot has been deposited on buildings at different times, researchers can calculate the reflectivity of buildings, indicating how dark they are.
It turned out that the building was clean for most of 900.
"In the last two centuries,
Black building
"This is a strange anomaly," brimbley Combe said . ".
"In a sense, we are now back in medieval England.
"Research into a limestone building at the University of Pittsburgh called the learning Cathedral shows that this cream
Even before the structure was completed in the 1930 s, the colored façade was black.
However, in the following decades, the air
The quality regulations mean that the black soot case is no longer a problem, and the most serious part of the building that has been soaked in rain has been naturally cleaned.
Climate models predict that with climate change, more rainfall may be received in the temperate zone, which means cities like London will become lighter.
But natural removal of black and gray deposits may reveal other changes in the stone, Gross said.
She and Brimblecombe have shown that no longer using coal fuel has made the Tower of London slightly yellow and red --brown hues.
This is the result of oxidation of organic compounds in diesel and gasoline smoke.
This tone may have been around for some time in this and other buildings, but will be hidden by the black carbon shell.
Cliff Davidson of Carnegie Mellon University, who studied the cathedral, said that warming could promote these changes in tone.
"This will lead to a larger part [
Organic fuel compounds
It turns into gas instead of particles, "he said.
"The gas may be deposited on buildings faster.
Fossil fuels are also changing.
It is vital that cars and truck fuels now emit less sulfur than before.
Therefore, a cleaner fuel could mean a greener building.
The building will not be uniform green, yellow or red, according to Grossi
Brown, but there are different colors in different places.
For example, Moss and Moss prefer a humid environment and may settle in cracks and corners.
Whether we notice these subtle changes remains to be seen.
Gross surveyed visitors to Norwich Cathedral in England.
It turns out that if a building becomes darker or brighter, but knows nothing more about the change in tone, we may notice.
However, she believes that as the building as a whole becomes brighter and cleaner, we may become more sensitive to yellow, brown and green.
Journal references and colons;
General Environmental science (DOI: 10. 1016/j. scitotenv. 2008. 09. 037, in press);
Environmental Science and Technology (DOI: 10.
1021/es062417w and classification number and colon cancer. 10. 1021/es990520y)