I really like Richard's suggestions! Here are a couple more to think about:
- a lot of Eco-Councils in our Climate Change Lead Schools in the North East have a team of 'Climate Change Ambassadors' who monitor behaviours of students and staff at school and encourage them to behave in a more 'climate friendly way' (e.g. turn off lights, computers, projectors, recycle, walk to school etc.)...they've designed and produced team badges to show they are Ambassadors, and they give out slips to reward or remind everyone to keep being climate friendly!
- have your council design and produce your school's 'bag for life', and give them out to students, staff and local community!
Keep up the great work! 
'Never doubt that a small group of thoughtful, committed citizens can change the world.’ by Margaret Mead (She was a wonderfully inspiring, world-changing anthropologist and activitist). 
So...what extraordinary things can WE achieve TOGETHER as a BIG group of thoughtful, committed citizens about climate change? The sky's the limit!! 