What would make me step off a building 93 floors from the ground? I am 44 years old, a business consultant and author and I like to think of myself as sane, but now I know the answer: Outward Bound. Nothing less than the chance to raise £1m to send kids from all over the UK to Outward Bound's six UK centres would do the trick; that much I know. And I have to hope that, come 3 September, it will be enough to give me the courage to step off the top of Europe's tallest building, London's newest skyscraper, the Shard. Why?

I think it's fair to say that my friends would never describe me as out-doorsy or sporty in any way, so it was quite surprising to be invited to join the board of Outward Bound ten years ago.

But the organisation has its roots in Wales, in Aberdyfi on the West coast, a couple of miles from where my father was born, and that was a big draw for me. I also know from my experience of living in North Yorkshire that a day walking the hills gives you much more than muddy boots and a raging appetite. But it wasn't until I went to our OB centre in Ullswater that I realised just how much Outward Bound can do for our young people. I watched a group of young boys from a local Scouting pack tackle one of our more notorious challenges: the trapeze. They had to climb a telegraph pole and, securely harnessed, leap from the top to catch hold of a trapeze suspended nearby and be lowered to the ground. It's quite hard! One boy who had been the clown of the group, making cocky comments and giving the instructor some gip, found it nigh-on impossible when it came to it. He climbed to the top of the pole, but baulked at standing upright on the top when the hand-holes ran out. I watched in admiration as the OB instructor stood back and let the boys on the ground find their own way through. They shouted encouragement, formed a ring around the pole and eventually counted down together: Mr Cocky stood upright on top of the pole. Another countdown to the big leap and he was lowered to the ground in a Superman stance, beaming. The lesson? Together we can do it: we are all better than we know. Priceless.

So here are the stats: OB has six centres - one in Wales, three in Scotland and three in the Lake District. These centres currently host 25,000 young people every year. The kids come from a huge variety of backgrounds: some self-enrol during school holidays, some come in school parties and others are sent to us by local authorities when they've hit a problem in their lives. 70% need bursary help to fund their courses and many are from significantly disadvantaged backgrounds. They participate in groups, guided, chivvied and taught by one of our phenomenal OB instructors. Often, this positive role-modelling is an education in itself. Whether they're there for a week or for the three-week 'classic' course, the kids are challenged like never before and achieve things they never thought possible. That alone can change their lives, transforming their confidence and encouraging positive choices at home, in school and in their communities.

But we need to do more. In December, at a board meeting, the trustees were considering how to raise funds to complete a refurbishment of our original centre in Aberdyfi and how to build up our bursary fund to fill the gap between what kids can afford to pay and the cost of the courses. I suggested some kind of board challenge and put forward two or three (very puny) suggestions. The Chairman, HRH the Duke of York, had other ideas. Looking straight out of the window of Buckingham Palace where the unmistakeable silhouette of the Shard was rising above the London skyline, he said, "We need to be more Outward Bound about this. We should abseil down THAT!"

And so we will. Eight trustees, led by Prince Andrew, and six of our more courageous supporters will step off the top of the Shard in September. I will be the second down and, when I have to leave the board in December at the end of my term, I will I hope have raised enough money to repay OB for the inspiration and personal learning it has given me over the years. And you have to admit, it's one hell of a way to go!

Please help us - we need every penny we can raise. Thank you.

To sponsor Ffion, follow the link to www.descentoftheshard.com

To know more about Outward Bound, go to www.outwardbound.org