Plastics are made from petrochemicals whose environmental profiles are complicated at best. But some stand out as, if not cleaner, at least less dirty.
Roofing choices are complicated by heating tradeoffs, climate effects, and condensation, but proponents say reflective roofs still make sense in most climates.
Understanding reflectivity and emissivity of roofing materials is important to evaluating their effect on cooling loads and the urban heat island effect.
While roofs with solar panels are a plus, researchers suggest white roofs in Canada do more harm than good because of steep heating penalties.
There are big differences in environmental impacts of commercial roofing materials, but the biggest variable may be service life.