"We aren’t trying to take traffic away from Facebook,” says Ben Disney. “We’re not trying to take searches away from Google. We’re just focusing on one word, sustainability, and acting as a hub for that one single goal.”

Liam Muckleston adds, “We’re making something new”. That something new is Caydoo (pronounced key-doo), a social network for sustainable living, aimed at linking individuals, groups and communities across the world and enabling them to share, teach and talk.

Of course, the internet already allows that kind of connection but it isn’t being used to its full potential.

There isn’t a definitive home of sustainability on the web the way that Facebook is the place to catch up with friends or Twitter is the place for spreading and reading news. With the launch of Caydoo this week, Liam and Ben hope to change all that.

It all started in 2007, when the friends began noticing an increasing number of news reports and articles about carbon emissions and the projects people were undertaking to reduce their carbon emissions. They had started discussing what they could do to make changes in their own lives.

At about the same time, Facebook hit 250 million users (today it has 750 million).

Liam says: “We started thinking that a social network can actually wield some power and if we could create a network which we could put to good use then we might be able to affect some positive changes.”

Through their research with focus groups in Brighton and at conferences in London, they realised that people needed to know others were taking action before committing to action themselves, and that existing groups had problems connecting with other groups. Liam says: “There’s all this stuff going on but often people didn’t know each other, often groups are very closed and insular.

So we started to develop the idea of a social network.”

Running parallel to Caydoo is the Cadyoo trust, a pot of money generated from on-site revenue streams and channelled back into sustainable projects and initiatives.

Liam says: “It’s really self-perpetuating, it just keeps linking back into itself and other people.”

Both Liam and Ben left well-paying sales jobs to dedicate themselves to the project and the development between then and now has been as personal as it has professional.

Ben says: “If we’d built this site four years ago, it would have been very different to what we’ve created now.

We needed to go on this journey of speaking to people, researching, refining our ideas and becoming very, very passionate about it.”

The site will be tested across Brighton and Hove until the end of the year when it will be rolled out globally.

So why this city? Ben says: “Brighton and Hove is the centre of the sustainability movement in this country and we want to be based here. There are a lot of IT professionals, there are a lot of environmental professionals. Why would we want to be anywhere else?”

* Visit www.caydoo.com