a) The damage to the environment during mining or harvesting of the basic material.
b) How much damage in relation to the quantity of materials (what else is disturbed or damaged?).
c) The source, size, or renewability of the basic material.
d) The recycle content.
e) Waste residue, solid or liquid, in production.
f) The air pollution due to manufacture and production.
g) The embodied energy
h) The energy consumed during transportation to site of usage.
i) The energy consumed on-site for erection or assembling.
j) The on-site waste and packaging.
k) The maintenance required during the life-cycle.
l) The environmental impact during the life-cycle (i.e, toxic emissions).
m) The energy and effects associated with demolition/disposal at the end of the life-cycle.
n) The recyclability of the demolished/dissembled material.
Here are some other paving alternatives. I don't believe that these products are one size fits all solution. I think that every project is unique considering the design intent as well as budget and client.
Fly ash concrete via Studio Green greatly reduces co2. Keep in mind for every 1 ton of Portland Cement produces 1 ton of co2
Permapave are a porous paver that are grouted in a polymer concrete set on top of a gravel base. These pavers act as a filter that prevent runoff contaminants from entering the storm drains and help recharge local groundwater.
Flexi pave is a porous paving that is a great substitute for asphalt paving. It uses recycled products and comes in several colors. I would recommend it for light traffic areas and not parking lots because it tends to loosen with heavy automobile traffic.