Eco-Effective Decisions: Raise the Green Roof, Lower your Urban Heat Island

Editor's note: Please welcome Green Options' newest writer, Elizabeth Redmond. Elizabeth is a sustainable designer working in Ann Arbor, Michigan. Her past experiences include working with her sister Sara Snow on a Discovery Health TV series called Get Fresh with Sara Snow, where she researched sustainability and built environment content.

I asked Elizabeth to give me an "elevator pitch" of her focus here at Green Options. Her response:

Today's green products and services seem to be an eclectic collection of "lighter tread". I propose that we begin to design and interact with products and systems that encourage heavy treading, where a heavy active footprint is one step in the right direction without a half step in the other. My objective is to tell you how things work, and enable you with the information to make responsible, and conscious decisions about society, lifestyle, health, and sustainability.

More than tornadoes, hurricanes, snow, or cold weather itself, heat is the number one weather related cause of death in the United States. So urban dwellers (that means half of us in this world) beware! Much of our urban heat is due to a phenomena called the Urban Heat Island effect. An Urban Heat Island is a metropolitan zone that is warmer than the surrounding, less developed area. The EPA reports that "On hot summer days, urban air can be 2-10°F [2-6°C] hotter than the surrounding countryside”. What does this mean? It’s going to be a hot summer, but luckily we can do a couple of things to help cool your stroll down the sidewalk.

First, how does this phenomena work? It is all about the energy transfer of solar radiation to our built environment. Lets go back to high school physics and review. All you need to know is that heat from the sun (radiation) gets stored in our constructed impervious and dark surfaces such as concrete and pavement (insulators). During the day these surfaces of high heat capacity collectively act as a massive heat energy reservoir. (I.e.: concrete can retain nearly 2000 times the heat as an equivalent volume of air). Next, the heat on the surface of these materials mixes with the already hot air and you experience a hot gust that feels dense enough to chew on (convection).