I saw this question [Comparing things (eg. as good as)](https://french.stackexchange.com/questions/101/comparing-things-eg-as-good-as)
and I have a problem:

Is there any difference between these sentences?

> 
> La pollution est **pire** que l'année dernière.
> 
> 
> La pollution est **plus mauvaise** que l'année dernière.
> 
> 
>