My city recently passed a “cool roof” ordinance, which requires new roof installations to use more reflective materials. When you’re talking about a roof over conditioned space, the benefit isn’t just reflecting more infrared back into space, it’s also reducing the AC load on the building below and thus global warming due to energy use.
Globally it wont make a difference of course.
If adopted at scale, maybe it could. Apparently 10% of the Earth’s surface is currently covered by ice and 3% of it is urban, so if all the urban areas were covered in white surfaces the effect on Earth’s albedo could be about 1/3 as strong as the ice caps’. (Maybe more, considering that urban areas are at lower latitudes.)
My city recently passed a “cool roof” ordinance, which requires new roof installations to use more reflective materials. When you’re talking about a roof over conditioned space, the benefit isn’t just reflecting more infrared back into space, it’s also reducing the AC load on the building below and thus global warming due to energy use.
If adopted at scale, maybe it could. Apparently 10% of the Earth’s surface is currently covered by ice and 3% of it is urban, so if all the urban areas were covered in white surfaces the effect on Earth’s albedo could be about 1/3 as strong as the ice caps’. (Maybe more, considering that urban areas are at lower latitudes.)