It's been awhile since the last time I discussed bioengineered
and genetically modified materials (GM). Since that time, the
Higg Index (http://tinyurl.com/bng2hdv) has been promoted as a
way to compare the environmental impact of materials used in
apparel and footwear. Here’s a sample: 36.1—Polypropylene: A
byproduct of oil refining and natural-gas processing, this
material—often used in long underwear—uses little land, water or
energy and produces little waste; low use of carcinogens,
endocrine disruptors or other toxic chemicals. 30.7—Silk fabric:
Chemically clean and leaving little waste, it scores high for
sustainability, though its production does emit a high level of
greenhouse gases. 27.5—Leather (corn-fed): There is very little
waste in its production compared with other materials, so it has
a higher overall score than many materials, even though it ranks
lower on land use; cows require large amounts of feed (which in
turn requires pesticides and fertilizer) and pasture land.
Animal-welfare issues ar