The festival is following the Keep Britain Tidy programme to progress its pledge to become an international Green Flag Award Eco-School.
The first day focused on the ‘three Rs’ – re-using, reducing and recycling.
Pupils brought in waste packaging to sort. Working in house teams, some created a giant world map from newspaper and other recyclables materials, while others researched where the packaging was produced, how far it had travelled and how.
Day two was about understanding the life-cycle of products, with the focus on what is involved in making mobile phones and jeans in a session led by parent and sustainability expert Abbi Lee.
Waverley Borough Council’s environment portfolio holder and Green Party councillor Steve Williams explained what it means to be ‘carbon neutral’.
On the final day, St Ives parent wedding dress designer Caroline Arthur, showed how to upcycle clothes and buying clothes in charity shops.
Pupils made eco-friendly Christmas decorations from pine cones and wood ready for a less wasteful Christmas.
Before half term, they also took part in a Hallowe’en costume swap.
Headteacher Kay Goldsworthy said: “Our first green festival has been a huge success.
“All our pupils learned about the environmental issues facing our world and how we are all responsible for making our future more sustainable.
“I’ve been delighted to see how responsive the children have been to all the ideas that have been discussed.
“Long may it continue.”