I don't think Nicolas Hulot is serious about running for president, he's trying to influence the platforms of other candidates, which i have no problem with since Nicolas Hulot has a lot of good ideas. But as popular as he is, he's not a credible candidate because his ideas are limited to the environment, a presidential candidate needs to have opinions and proposals about pretty much everything, not just one topic.
Here's a
website that keeps tracks of candidates opinions and proposals, that's quite interesting.