A career to improve the world?

I'm not sure what I want to do with my life, I'm 18 and I have the advantage of being a citizen of both Denmark and America. I've always fancied the arts, but my heart lies toward justice and human liberties.

How could I, or any of you, create a large impact to make the world a nicer place?

Which career path would help people the most?

Would I become an politician, and try to fight against the tides of other politicians who want to limit freedoms?

A defense lawyer, to try and save people from flawed laws?

A Regular Joe who joins protests?

A murderer, achieving freedoms by denying oppressing politicians and business tycoons the right to live? <---This one is a joke. Maybe.

I'm not sure what I should do with my future, all I know is that I love Skyrim, Watercolor, and helping people, but I get absolutely butt frustrated when I read stories of injustice. I'm frustrated that we, as a people can do little in terms to stop many of wrong things in this world, but I can also recognize that we can't fix them all. Atleast not at once.

If anything, discuss what careers could improve the world, your country, or even your town.

Also, sorry if this is in the wrong place.