Parents and children have been shown how small changes at home can help protect the environment for the future.
The London Green Lifestyle Show in Greenwich offered tips on recycling and saving energy in an attempt to make London a more sustainable city.
The event, held in south London on Sunday, World Environment Day, was powered with renewable energy sources.
A lifestyle area showcased new and innovative ways to "green" your home and save money.
Mayor of London Ken Livingstone, who organised the day, said: "I firmly believe that if children learn about the environment at an early age, it will determine their attitude to preserving it throughout their lives."
Advice was also given on healthy eating and how youngsters can improve their lifestyle.