Well not all of them. And not your actual clothes, although you can always donate your unwanted clothes to charity shops.
What they really want is photos of your favourite sustainable outfit.
Sustainable, or eco fashion, is all about clothes, shoes and accessories that have been produced in such a way as to reduce their impact on the environment.
You can tweet photos of your sustainable outfit to @Climate_Week or post it to their Facebook page, along with the story behind the outfit.
There are H&M vouchers to win, so we’re off to get our entry in and recommend you do the same quick!
Find out everything you need to know here: www.climateweek.com/2012/02/21/be-sustainable-be-stylish/