Global Warming and the Heat-Island Effect

In the series on alternate fuels and our future there was no mention made of climate change. Anyone with global warming foremost on their environmental agenda should realize that converting as quickly as possible to more environmentally friendly fuels would be beneficial. The conversion will reduce the amount of carbon dioxide introduced into the atmosphere through fossil fuel use.

It will not reduce the amount of carbon dioxide in the atmosphere. It also will not reduce the amount of heat retained by the green house gases. This brings me to question the poor choice of terms, climate change. The greenhouse effect was the first and most accurate term used. Greenhouse gases mainly carbon dioxide, methane and nitrous oxides in the atmosphere create a conditions like a greenhouse. Sunlight enters the greenhouse and warms the interior and most of the heat is retained.

Think of your car in the summer sun. With the windows rolled up it gets pretty hot in the car. Now take it one step more, if your car has a black interior, it gets mighty hot. With a white interior it gets hot but nothing like the darker interior. That is because dark colors absorb more of the sun's radiant energy and light colors reflect more.

With the use of the term climate change the actual effect greenhouse effect is lost to many readers. This is removing some of the emphasis on important elements that contribute to global warming.

One contributor to global warming is known as the Heat-Island Effect. Most scientists remove the heat-island effect from their calculations for global warming. While part of their logic is sound, there is a component of the heat-island effect that should be considered. Reflectivity of man made surfaces. If you have ever walked bare foot on a black asphalt road you know what I mean. Just as in the example of the car with the black interior, dark pavement and roofing materials contribute to heat retention.

Lighter colored pavements and roofing reflect more of the suns radiant energy than they absorb so white is a much better choice. Reflective paving materials are available and have been use in a number of locations. The increased reflectivity of paved surfaces and roofing can reduce heat-island effect by a significant amount in two ways.

First the reflective materials contribute less to local area heat retention. Second the reduced heat retention reduces air conditioning demand. Air conditioners generate a great deal of waste heat that contributes to the heat-island effect. Less waste heat, less heat-island effect. See the University of Berkley report.

The reduced number of trees in urban and newer suburban areas, contribute to the heat-island effect and the greenhouse effect. Many community revitalization projects include planting trees. More such projects should be considered.

What can you do to help reduce heat-island effect?

Get an energy audit. If you are in an older home you should definitely benefit. With energy conservation tax credits available, this is a great time to make an energy remodel. You will save money and help your environment.

Think trees not grass. That well manicured lawn is not a great idea. While grasses use CO2, when the clippings decompose that CO2 is released again. When you add the energy required to maintain the lawn it adds to your carbon account not reduces it. Trees are much more appropriate for storing carbon and properly located trees can reduce stored heat energy and your cooling bills.

While you are relaxing under your new shade tree enjoying the spare time you have not mowing the lawn, think about your roof. Is it solar reflective? If not think about lightening the color. As part of that energy remodel you will get a tax break.

Try calling your city council person or county commissioner and ask about repaving with lighter colored asphalt next time. You may want to mention to your local superstore's manager that lighter colored paving would be nice in the parking lot. While you have the manager's ear mention adding a few trees. Since you are Time Magazine's person of the year, maybe you should take this opportunity to set a better example.