I'm working on a small project, and the action takes place on a desert planet. The actors perform in front of a greenscreen and I'm gonna put in the desert sand image I made behind them. I want to give the background a little more life, so what I was thinking is animating some clouds and adding a heatwave/ mirage effect. (You know, what you'd see rising on a long Arizona highway)

Any help on how I can get this effect in Media Studio or After Effects? (I have MSP, so preferably in that prog)
Any help or related and inspirational poetry would be appreciated.

I figured out something using the WaterFlow filter in MSP. Needs a lot of tweaking though. Any other thoughts?

In After Effects: play around with the Distortion effects. Bulge and ripple for example.

Inspirational Poetry:
I do not like Green Eggs and Ham.
I do not like it...
Sam. I. Am.
Save Tibet, drink organic soy chai tea. Protest big corperations for no reason and use big words in casual conversation.
Post modern socio neo femminist liberty for underprivelaged politically oppressed genetically modified whales for contemplation of mind.
End Poem. Fin.