Asphalt Goes to the Landfill. Metal Gets Recycled.

Every asphalt roof that comes off a house goes somewhere, and that somewhere is almost always a landfill. Millions of tons of shingles go in the ground in this country every year, and they take a very long time to break down. That is the nature of the product: it is oil and granules on a mat, and nobody is recycling it at scale.

Metal is the other way around. A good share of what goes on your roof was recycled once already, and at the end of its life the panels are scrap steel that gets melted down and used again. The roof also lasts long enough that the question comes up far less often.

I do not think that alone should decide your roof. It is a real point in metal's favor if you are already leaning toward a long-term home. It is not a reason to spend the money if you are moving in five years. Now you have the context to weigh it.