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Are asphalt streets making our heat wave worse???

Most of the country has been locked in a record setting heat wave for 19 days or more while the southern 11 percent of the country (around the gulf coast) is facing one of the worst droughts in history. Is the blacktop surface of 94 percent of our roads, parking lots, big box stores and malls contributing to the heat domes forming over our cities?
Posted: August 2, 2011 - 3:27PM
Author: Don Bain

The Department of Energy’s Heat Dome Island Group says it is and has been studying the problem for over eight years. They report on a warm summer day, urban areas tend to be 6 to 8 degrees warmer than the surrounding countryside. This effect is referred to as an Urban Heat Island.

These higher temperatures increase the power demands on the electrical grid and cause deterioration of air quality. It is all made worse by the solar gain of large asphalt areas and the corresponding lack of trees and vegetation.

Of course, is happy to tell you, “Low consumption of energy for production and construction, low emission of greenhouse gases, and conservation of natural resources help to make asphalt the environmental pavement of choice.”

They go on to remark,” Asphalt is the sustainable material for constructing pavements. From the production of the paving material, to the placement of the pavement on the road, to rehabilitation, through recycling, asphalt pavements minimize impact on the environment.”

They cite reasons including the fact it takes less energy to pave an area with asphalt than other surfacing materials. That congestion wastes time, money and fuel, so logically if we just paved the entire country everything would be heavenly. Oh and since asphalt can be almost completely recycled, it’s a good thing.

They say the road last because the roadbed does, but asphalt has to be replaced every two years, which is why the names of the seasons have been changed. You probably heard the new lineup: Fall, Winter, Spring and Construction.

In some ways, it is a good thing we now add ground up tires to our roadways – it at least helps get rid of the mountains of spent tires we are constantly creating. On the other hand, it makes the road even blacker and more energy absorbent, but it doesn’t keep that energy within releasing it into the ambient environment and simply helping to create these Urban Heat Islands.

You don’t need the government to tell you this if you’ve ever walked across a large asphalt parking lot on a summer afternoon. You can clearly feel the heat rising from the blackened acreage.

On July 19, ABC news in Phoenix reported a man received second-degree burns on his bare feet just walking across the street to catch the mailman. The report noted asphalt surfaces could reach 150 degrees in triple digit weather.

Or maybe you’ve seen the bumps and dips in the road caused when an urban bus has to stop on a very hot day – it actually sinks into the road causing a smooth “pothole” and bump of several inches in height.

You might even know a woman whose spike heel has sunk into warm asphalt – perish the thought of that happening to her Manolo Blahniks – some poor mall manager would never hear the end of it!

This information was brought to our attention by a press release from Emerald Cities – they are hawking a product to ameliorate this problem. If you’re interested in what they have to say, click here.