The urban "heat island" effect occurs in most
of the large cities of the world. This phenomenon
has been shown to actually change weather patterns
in some of these cities. Roads and building
rooftops absorb a significant amount of heat
during daylight hours. This heat, in turn,
is radiated back into the atmosphere, causing
further warming. To compound the problem, additional
heat is emitted by vehicles and HVAC systems.
These factors can result in a 6- to 10-degree
temperature increase in large cities. GreenGrid® green
roofs help to insulate and shade buildings. Also,
through evapotranspiration, or the return of moisture to the air, plants cool the atmosphere
around them. In large scale usage, these factors
have the potential to
significantly reduce the urban heat island effect
within these cities. 
