I didn't read it, but in the latest IET online news is an article re: using some vegetable materials in tyre manufacture. Whether it is to reduce the carbon content I have no idea. I'll see if I can find the article.
Graham (G4FUJ)
Sold L44FOR 4/4 Giallo Fly '11 MINI Countryman Cooper D All4 '90 LR 90 SW