Here is a link to some Cartoon Competitions running all year out of Europe.
Scroll down to competition with the 30 June 2012 deadline and there is a competition with an 'eco-story' as a possible eco-cartoon.
'New cities' could also fit within the eco-theme framework.
We environmentalists are learning to be a lot more visual in the way we communicate our messages, which is a glorious thing, really. This is great as we are learning to use our RIGHT BRAINS more in the way we express our messages.