The largest contribution to the CO2 footprint of races - by far - is the travel involved in getting to/from the start/finish. The kit worn only makes a small contribution, though almost all of it will end up in landfill, particularly shoes, which are very difficult to recycle.

Damian contributes to doing his bit by flying less, travelling by train/bus/shared car where possible, and wearing kit for longer, repairing it, and owning less. He is of course given kit to try for free - at one stage he had 25 pairs of shoes on the go.

The best bit of kit for the planet is the bit we don't buy.

I enquired about repairing the zip on a much loved lightweight Haglofs top recently - £50! Such repairs should be subsidised by the manufactures. With due respect to Haglofs they had sent me a zip slider free of charge, but unfortunately that did not solve the problem.