09/26/2012 01:12 pm ET Updated Nov 26, 2012

Greetings From the Green Carpet Challenge

First we take Manhattan... Greetings from New York where I was given a huge opportunity: to present the Green Carpet Challenge to a first ladies luncheon followed by a state dinner with UN Secretary General, Ban Ki-moon. When the great Franca Sozzani first suggested this day to me a few months ago I think my bottom lip probably trembled with fear. But today I woke up reveling in such an opportunity. Firstly to get to talk in front of a collection of first ladies at a lunch arranged by a brilliant organization, Fashion 4 Development.

The lunch began with the in-fatiguable Evie Evangelou, co-founder and global chair of F4D (fashion for development), followed Mrs. Ban, first lady of the United Nations. Franca Sozzani received the WF4D's 2012 Fashion and Humanity Award for her outstanding work for Fashion 4 Development in Africa. (I hope you managed to get a copy of Sozzani's L'Uomo Vogue Africa issue which gives just a tiny clue to all the work she does around fashion and development.) Congratulations to Toyin Saraki, founder of the Well Being Foundation in Nigeria, who was presented with F4D's 2012 Angel Award.

Co-Host HRH Crown Princess Mette-Marit is another example of active citizen who understands the potential of fashion to development. She introduced follow Norwegian and a great friend to the GCC, designer Leila Hafzi. Leila is a passionate ethical fashion designer. (I wore her to the 2010 BAFTAs and her bright yellow dress remains one of my all-time favorites.) It was so inspiring to hear tell the story of her fashion line produced in a small co-operative and unit in Kathmandu, Nepal established around trained and skilled tailors. Then of course it was my turn! I'll leave it to the audience to judge my performance, but the case I have tried to make in New York to both audiences is that ethics and glamour should and need to go together not just in the wardrobes of first ladies but for everybody.

And all day I've been attempting to persuade anyone who'll listen that sustainable fashion can give us all the chance to be active citizens through our wardrobes. Of course as well as what I'm going to say, I've been preoccupied by what I'm going to wear. The great U.S. designer, Tory Burch had to be the one for the first ladies luncheon. Tory created a wonderful piece for me to GCC criteria incorporating 100 percent silk tulle, organic silk chiffon and re-purposed beads from her own archive. I felt a million (US) dollars in it! For the state dinner I wore an off-the-peg beautiful dress from the brilliant Leila Hafzi, which I made a beeline for in her tiny Milan showroom.

It has a sweet Tiana corsage, in 100 percent chiffon silk and a Sabina Skirt made of 100 percent natural unbleached sustainable silk. All fabrics are hand and piece dyed within Leila's production unit in Katmandu that has the sort of water recycling standards and pollution controls that put many facilities to shame. And despite the nerves and the excitement I actually felt great and enjoyed myself, because that's the type of confidence sustainable fashion gives you!