Freda Eyden looks at the green flag fluttering outside the classroom window and remembers how the journey to eco-school status began. It was 10 years ago, and staff at Woodheys primary, in the Manchester suburb of Sale, were considering how to smarten up the playground.

“We were about to buy a pot of blue paint,” says Ms Eyden, a classroom assistant who now doubles as the school’s environmental projects co-ordinator. “But a parent suggested that we do murals instead.”

The children drew designs, and staff and parents helped with the painting.

And then Ms Eyden saw an advert for an environmental teamwork award. They put together a presentation and were amazed when they won the pound;800 prize.

“We decided to spend the money creating a small garden in front of each mural, with planting that would reflect the pictures,” she says.

As the gardens flourished and horticulture became part of the school routine, children, staff and parents found themselves developing a greater awareness of nature and the environment. The more they found out about saving water and making compost, the more they became interested in the wider issues of recycling and energy conservation. Sustainability became the watchword, and soon the children were monitoring a variety of activities, from turning off lights to recycling paper.

Before long, the school had won its green flag - a top award. It had even formed an eco-school council, where delegates elected by their classmates help take decisions affecting school life.

All of which is music to the ears of Will Rogowski, head of marketing and communications at the United Nations Environment Programme World Conservation Monitoring Centre in Cambridge. Pointing to the latest warnings from an international task force on the alarming rate and extent of climate change, he says: “If that isn’t a wake-up call to take real action, I don’t know what is.”

An essential facet of that action, he says, must be familiarising children with environmental issues. For one thing, he says, they might be frightened unless they understand the news. And for another, educating children is the key to educating the community: “You can never ignore the power of children to influence their parents.”

To this end, the UN’s Youth and Children’s Unit, based in Nairobi, Kenya, holds a children’s summit, where young people from around the world talk about the environment from a global perspective.

Theo Oben, who heads the unit, explains: “The only way to achieve sustainability is by developing a generation that is fully conscious of the implications of their decisions.” And, as with most things environmental, he says, “those implications are global”, meaning that the awareness of problems and ways of coping with them must also be global.

At Woodheys primary, the head, Laura Daniels, has encouraged links with several schools in other countries. Through an international sustainable sities project, co-ordinated by the Development Education Project in Manchester, Woodheys became part of a cluster of schools working with similar clusters in Canada, Brazil, Italy, India and Gambia.

After winning a World Wide Fund for Nature essay competition, Freda Eyden attended the world summit on sustainable development in Johannesburg, South Africa, an experience that has helped to bring the concept of education for sustainable development to life for the whole school.

“The point is, is that it’s no use just thinking locally or globally,” she says. “If you spend all your time talking to children about other countries and they haven’t a clue what’s going on around the corner, they are not getting a global perspective at all.

“So we encourage them to look at their own area and think about it and share it with other people. And when you start to compare and contrast, you find that an awful lot of stuff is the same... that kids in other parts of the world also like getting together with their friends and kicking a ball around on a piece of ground.”

Above all, she says, it is important to avoid the mistakes of the past.

“You can’t go into a classroom and begin talking patronisingly about poor children in Africa who have no toys or computers. I know they have some terrible problems, but they have an awful lot of stuff we don’t. It’s a two-way street, and in many ways, they are richer than we are with our superficial materialist values, and they certainly have more connection with each other and with the environment.

“Something like this awful tsunami has helped to introduce ideas about the bonding of humanity, and you haven’t needed to hammer home the global thing - it has come out of it naturally. And let’s face it, we can’t just say we do our little bit of recycling, or isolate our own little part of the world and make it nice and green. It’s a common world, and we’ve all got to live on the planet as global citizens.”

The Eco School programme is designed to promote environmental awareness in a way that links to a range of curriculum subjects, including citizenship, PSHE and education for sustainable development. It involves the whole school and wider community.www.eco-schools.org.uk