Ten students from Chinese International School (CIS) decided to clear an area near their school of cars with idling engines.
The students launched a scheme to persuade drivers to switch off their idling engines.
The students made rounds after lessons. Then they talked to drivers who left their engines on in order to keep the air conditioning working.
'We approached the drivers and politely asked them to switch off their engines. Flyers about the effects of the polluting practice were also given out. We gave a bottle of water to each driver who agreed to turn off their engine,' said Christ Chan, a Year 10 student.
Approaching strangers turned out to be a less challenging challenge than the students had thought. 'More than 80 per cent of the drivers agreed to our request. They were also willing to listen to our views on environmental conservation,' said 15-year-old Christ.
For Andrea See, 14, language was the biggest obstacle in her environmental work.