Urban Heat Islands

What is an Urban Heat Island?

Heat Islands are typically more densely populated urban areas lacking in natural vegetation. As a result of the concentration of concrete, glass, asphalt, and other modern building materials, these areas can experience increases in temperature of 2-5 degrees F during the day . . . and increases of as much as 20-25 degrees in the evenings, compared to surrounding non-urban areas in the immediate vicinity.

By retaining so much heat in a condensed area, these Heat Islands increase peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and water quality.

Urban Heat Island map from NASA  The EPA has recognized this phenomenon, and has produced a compendium of strategies to help combat Urban Heat Islands. There are five strategies we can employ to help combat this effect:

Strategies and Technologies

  • Trees and Vegetation – Increasing tree and vegetation cover lowers surface and air temperatures by providing shade and cooling through evapotranspiration. Trees and vegetation can also reduce stormwater runoff and protect against erosion.
  • Green Roofs – Growing a vegetative layer (plants, shrubs, grasses, and/or trees) on a rooftop reduces temperatures of the roof surface and the surrounding air and improves stormwater management. Also called “rooftop gardens” or “eco-roofs,” green roofs achieve these benefits by providing shade and removing heat from the air through evapotranspiration.
  • Cool Roofs – Installing a cool roof – one made of materials or coatings that significantly reflect sunlight and heat away from a building – reduces roof temperatures, increases the comfort of occupants, and lowers energy demand.
  • Cool Pavements – Using paving materials on sidewalks, parking lots, and streets that remain cooler than conventional pavements (by reflecting more solar energy and enhancing water evaporation) not only cools the pavement surface and surrounding air, but can also reduce stormwater runoff and improve nighttime visibility.
  • Smart Growth – These practices cover a range of development and conservation strategies that help protect the natural environment and at the same time make our communities more attractive, economically stronger, and more livable.

What is Great Growins doing to help?

A big part of our mission is to provide living spaces for humans – in the most literal sense. By leveraging technology like vertical planters, living walls, urban gardening, and similar interior and exterior plantscapes, we – along with our customers – are helping reduce the footprint of our own Urban Heat Island – Indianapolis.

What can I do to help?

The EPA has a great guide on how you can help reduce heat islands. But its just the tip of the iceberg – our staff is well-versed in finding creative ways to bring life-giving oxygen into your family’s living space or your work space with affordable, easy to maintain plantscapes in any environment. We also provide provide products and services to non-profit organizations in our city who are helping fight the battle. Stop by, call, or email us, and we’ll help you put together a plan to help contribute to reducing Indianapolis’ heat island footprint.