Applying Zoom Effect In cocos2D gaming environment?

I'm working on a game with cocos2D game engine and make load all the sprites while it load the level, now as because some of sprites (obstacles) are taller than 320 pixel, thus it seems difficult to check them out. So for the convenience sake I want to apply ZOOM IN and ZOOM out effect, which minimizes entire level's all sprites at once, and in zoom out case these will resided to there old position.

Can I achieve this?

If yes, then how?

Please tell about pinch zoom also.