Environment effects on screen

While I was strolling about Limsa Lominsa, the weather was foggy. I started thinking about how that suited the ocean surroundings, and wished I could smell the salty air. Then a thought came to mind: wouldn't it have been nice if the surroundings occationally set its marks on the player's screen? Just briefly of course, and not too much, or it could quickly become annoying. In example, when running near ocean water during a storm, small salt stains would spatter the corners of the screen, and soon after fade away. And rain could leave small droplets in the same manner.

I played Batman: Arkham Asylum, which used this effects when you busted toxic plants; putrid liquid would splash over the screen and quickly fade. A very nice effect indeed.

But this would be an idea for the future, when all problems have been sorted out, content added and the game is running steadily.

What would you think about such an effect?