First Light by Rebecca Stead would be a great book to read if you enjoyed Jeanne DuPrau's City of Ember and it's sequels. First Light tells two stories that eventually connect in unexpected ways.
The story of Peter tells how his family temporarily moves to Greenland so his father can study glaciers and global warming. Peter bonds with one of the sled dogs, explores Greenland, and makes a new friend. The story of Thea tells of another world with no sun, dogs, and too many secrets. When Thea finds a map to the surface the two stories begin to connect.
The choices Peter and Thea make may save or destroy their worlds. Try out this 2009-2010 Truman Nominee, it fits well into the Science Fiction/Fantasy genre, with realism added by the discussion of global warming.