A new forest of more than 6,000 trees is being created by environmentally-friendly pupils from a West Yorkshire secondary school.
Pupils from the school have planted more than 6,000 trees
Youngsters from Bradford Grammar School pupils spent three days planting the forest in Laycock, Keighley, as part of a project to repay their carbon debt.
Religious education teacher Mike De Villiers said more than 600 pupils aged between six and 14 had taken part.
The forest will be looked after by the Bradford Environmental Action Trust.
Mr De Villiers said the project started 18 months ago when pupils began to calculate their total carbon debt over a year-long period, taking into account how they travelled to school and how many plane trips they took each year.
He said: "We set up a calculator on our website so that every pupil could calculate what their carbon debt was.
"They came up with the idea of planting trees to repay their carbon debt and the mother of one of our pupils said we could use three of her fields."
After 18 months of planning and preparation, the forest of oak, hawthorne, field maple, scotch pine and larch trees was ready to be planted.
Mr De Villiers said the project had inspired the youngsters to be more aware of their environment.
He said: "I had a report of one six-year-old going home and sitting down with his dad and saying 'in 40 years on is going to be too late dad, we have to do something now'.
"I think that is the whole message.
"They've been really thrilled to be out here - they've been telling me how many trees they have planted, and how they are making up their carbon debt."