The future of our planet could depend on keeping the environment on the school curriculum. Yet many heads are now discovering that the money for their schools' ecology projects is running out.
The Eco-Schools programme, involving 800 schools, will be forced to all but shut down in July. And the fear is that with it will go the best way of educating the next generation about the environment - practical projects with tangible results.
"We receive pound;330,000 a year, but that funding runs out in August," said Sue Nelson, assistant chief executive of Encams (Environmental Campaigns), the charity which co-ordinates the Eco-Schools programme in England. "We've not even been able to get a meeting with the Department for Education and Skills to discuss this."
Schools are potentially a powerhouse of environmental education in the UK.
They represent a huge proportion of the state's property estate, with more than 40,000 buildings. They consume 25 per cent of the public-sector's energy costs.
And they have big lessons - both ecological and financial - to learn. Some school heating systems waste 40 per cent of the energy they burn. Estimates from Encams suggest that savings of pound;100 million a year could be made if energy-efficient measures were adopted in schools. Energy-saving light bulbs alone can save pound;10 per bulb each year. New European Union legislation, obliging schools to publish their energy consumption levels, will come into effect in 2006.
Eco-Schools is a source of curriculum ideas and materials, linking the environment with personal, social and health education and citizenship. It is behind hundreds of practical school projects, from flushing lavatories with rainwater to recycling paper or building a sensory garden for the blind. The programme, which in 10 years has helped 5,000 schools, awards a green flag to environmentally-friendly schools.
"We are trying all sorts of routes for funding. I've approached almost every corporate body I can think of," says Ms Nelson. "But the problem is that we need long-term funding, not just one year's money which leaves us with the same problem in a few months' time.
"The Government should put its money where its mouth is. Green-flag schools cut running costs quite significantly. But we get passed between the DfES and the Department for Environment, Food, and Rural Affairs when we ask for money. No one seems to want to own this one."
The reason for the loss of funding is complicated. Government support for organisations promoting the green agenda in schools has been funded through the landfill tax credit scheme.
This programme takes money from businesses that use landfill sites in the form of fees and recycles it back into the community as grants to support environmental projects.
The environmental organisations that work with schools claim that up to pound;20m of landfill tax has been used to support education projects since the start of the scheme, and that current projects are funded to the value of pound;6m.
But the landfill credit programme was revised in 2002, when funding for education projects was cut. Lobbying by charities and environmental organisations since then has met with little response.
Yet education for sustainable development (ESD) has been a cross-curricular topic in schools for three years, and six months ago Charles Clarke, the Education Secretary, launched an "action plan for sustainable development" with the words: "Gone are the days when we could ignore this. It is no longer a side issue - caring about our environment is important for us all.
"In education, our job is not only to operate in a more environmentally sustainable way, but to teach it as well."
The organisations affected by the loss of money, which reaches them via Defra, are WasteWatch, a charity that has worked with more than 800 schools since 1998; Learning for Landscapes; Global Action Plan; Encams; the Recycling Consortium; Globe UK and the Derby Wildlife Trust.
Assuming no rescue package is found, Eco-Schools is likely to be run as an Encams web service, with no school visits and no individual advice.
"Prince Charles has visited an eco-school and was impressed," says Ms Nelson. "So as a last resort I'll try the Duchy of Cornwall."