Scientists at the Lawrence Berkeley National Laboratory (LBNL) have created an interactive map that displays the solar reflectance (or albedo) of individual roofs in five major California cities – Bakersfield, Long Beach, Los Angeles, San Francisco, and San Jose.   This is the first time scientists have attempted to map the reflectivity of entire cities.

A white / high-albedo cool roof reflects 80% of the sun’s heat, decreasing solar heating of the building. This reduces the need for air conditioning and lowers energy bills. Cool roofs could also partially counter increased urban temperatures brought on by climate change.

This map allows users to zoom in on a specific rooftop to see how it compares to the albedo of a white roof, or other roofs in the city, and is designed to help cities develop policies that could lead to cooler cities.

Ronnen Levinson, head of LBNL’s Heat Island Group and Board Member of the Global Cool Cities Alliance says this new map can be a useful tool for cities:

To assess these potential benefits for a particular city, we need to measure the reflectance of its roofs with good spatial and spectral resolution.  Our map helps bring this into focus.

You can explore LBNL’s new interactive map HERE.