Much of the green movement is still gripped by post-Copenhagen tristesse – sadness caused by the loss of so much hope vested in an even half-decent agreement on climate change in December 2009. Some are trying to make the best of a bad outcome, but many remain paralysed by that failure of international leadership.

Where to campaign now, and for what? The more recent 2010 meeting in Cancún marshalled the depressed and the cynical, but not the world leaders.

But was it wise to invest so much hope in a meeting of heads of state in the first place? Did we really think the process and the stage management would enable 192 nations to agree what was in effect a common energy policy?

In Copenhagen the national leaders were caught as much on the hop as were the conference organisers and a huge number of NGOs. No one behaved well. Lazily, the leaders imagined their ‘sherpas’ would fix some common enough ground so they could fly in and cross the odd image-boosting ‘T’. Foolishly, the organisers failed to understand that this really was decision time. Disgracefully, the campaigning NGOs were unable to construct an intelligible model of what a sustainable future could look like.

I don’t want to underplay the difficulties of shifting anything or anyone onto a more sustainable trajectory, but short of some tremendous catastrophe, it won’t come out of huge international set pieces. Moreover, even if all countries had signed up to a far-reaching agreement to cut CO2, this would still have to be turned into action on the ground. Kofi Annan made this point forcefully at the World Summit on Sustainable Development in 2002. The crisis, he said, is in implementation. We know what to do, so why don’t we do it?

We’ve made a historical error in adopting a way of relating to each other that is mediated by the career of cash, rather than how successful we are in nurturing each other and the rest of life on Earth. But it was in this perverse (obstinately in the wrong; against the truth) world where financial power always trumps human welfare that the Copenhagen conference was conducted. And the NGOs proved that mass lobbying was not enough to build comprehension of, never mind confidence in, sustainability as a new logic within which to make sense of what to do next.

So is the green movement at a turning point? Yes, I would say it is. Strategies and tactics of the last few decades have done a lot to raise awareness, though little to push implementation. We used to say “Think of your grandchildren”, but decades of inaction means that worrying about future generations has been overtaken by worries about this one. For me, the only strategy left to us is positive deviance. This simply means doing the right thing despite being surrounded by the wrong institutional structures.

For 15 years now, Forum for the Future has run a Leadership for Sustainable Development taught masters programme, each year graduating students with the knowledge and skills to operate as positive deviants wherever they are living and working. And it is my own learning from setting up and teaching some of this course that I’ve tried to distil in a book, The Positive Deviant: Sustainability Leadership in a Perverse World.

There are so very few courses like ours that there is little hope of flooding the job market with sustainability-literate people any time soon. So thankfully this is something that can be learnt and tried at home or at work because, counter to much theory about leadership, there is no one model or framework to squeeze yourself into. We each have a unique leadership persona, and working out what it is and building our confidence in using it for sustainability outcomes is what matters most. Helping as many people as possible to do that – whether you are starting out anew, or filling gaps – is why I wrote this book.

Forum’s students report from their placement organisations a growing number of positive deviants. Everyone can become one. If unsustainable development was caused by zillions of unknowingly (I am being generous) wrong decisions and actions, then sustainability can be achieved through zillions of knowingly right decisions and actions.

All you need to get started is in the book: enough knowledge, a range of skills to practise, plus lots of ideas, tools and devices to make it more likely that your decisions and actions contribute to sustainable development than not.

(PS David Cameron has a copy already!)

The Positive Deviant may be bought at a discount via www.forumforthefuture.org (Proceeds to Forum for the Future). To watch a free webinar by Sara Parkin visit www.earthscan.co.uk/earthcasts

Sara Parkin is a founder director of Forum for the Future.