Why is land use albedo a negative forcing?

The heat island effect affects local conditions in a serious manner. However when looking at the following illustration surface albedo is shown as a negative forcing.

http://en.wikipedia.org/wiki/File:Radiative-forcings.svg

How is it possible that the heat capacity of urban development is a negative forcing? Does land use albedo really counteract solar irradiation? How is the heat island affect measured quantitatively?

Am I missing something?

admin

Leave a Reply

Your email address will not be published. Required fields are marked *