Convince Congress to pass a law which creates a tax on any non residential building that does not have at least 90% of the roof space either painted white OR at least 30% of the usable space on the roof used to host hot water heaters/solar electricity units OR at least 80% of the roof covered in green plants.
Let this be enforced by an annual tax based on the foundation's square footage of the building in question. And let this be a tax which is intended to be expensive for those buildings where painting the roof would be relatively simple and inexpensive; but not prohibitive and cruel for those buildings where painting the roof would be either impossible or highly expensive/destructive (i.e. iconic buildings or those with helicopter landing pads or those with rooftop patios).