Clay tiles are a highly durable roofing material, popular in warm regions. Light-colored clay tiles are one of the best choices from an environmental and energy-efficiency standpoint, especially in regions where they are common.
Recyclable metal roofing
Metal roofing is a much better overall choice than shingles. It lasts longer and is recyclable, which is important for the environment.
See, for more details:
Metal Roofs Efficiency
Cities have warmer temperatures than the surrounding rural areas: that's the urban heat island phenomenon.
Roofs are a major cause of this phenomenon, associated with the greenhouse effect and the widespread use of air conditioning.
There are now recycled shingles, including “reflective cool shingles”, to reduce the heat island effect (see Box). Recycled algae-resistant shingles can last a bit longer than traditional shingles.
Recycled Rubber and plastic roofing
There are dozens of companies recycling millions of old car tires into cheap rubber shingles.
Like with car tires, there are also dozens of companies recycling plastic and metal into roofing products.
Plastic recycled shingles are lightweight and cheap, looking like true slate shingles.
Plastic recycled shingles do not contaminate the rainwater, contrary to rubber roofing or asphalt shingles... They may also be advantageous in snowy climates, to prevent roof ice dams.
Spray-on foam roofing (Flat roofs)
Poly-iso (poly-isocyanurate) is a common option for flat roofs. It provides a continuous roof surface that doesn't leak and is very durable.
Its yellow color is not very attractive, but if color doesn't matter to you, it is one of the best and most durable solutions to cool your flat roof and to keep air conditioning consumption low.
See also: Energy Efficient Roofing Membranes