Here's a way you can start an inquiry using the Slic.nz D.R.E.A.M model. Try this video, "Save Our Planet", to ignite the wonder inside and start class and group discussion. It doesn't give the children too much information, however allows them to DREAM about what the world could be like in the future if we don't make some simple changes.
Next, let them go off on their own tangents, taking inspiration from the video and prior knowledge. A bit like this...
Let's let the children dream a bit! Let them create a drama piece on what it would be like in this world. Record it using an iPad! Write stories! Make a soundscape! Let the children BE CREATIVE!
See what other fantastic videos you can find out there. Youtube is full of them! Heaps of ways to ignite little dreams and create a big imagination.