Here are some things science is settled on:
The earth being round.
The earth is not round http://www.scientificamerican....
The earth orbiting the sun.
Technically, the earth does not orbit the sun. It orbits the central mass of the solar system.
Science IS settled on a lot of issues. AGW is a new one, but something we can do something about (well, 10 years ago).
Just because there is a preponderance of evidence that our explanation of an observed phenomenon is correct, it does not mean the science is settled. It means that we have a good explanation. If a better explanation comes along and it fills in areas where the first did not, we adjust our understanding of the universe and the accepted scientific belief is changed.
Ill add that if you are getting your science from grade school or the news outlets, then you need to realize that you are not reading the science and are instead reading an opinion.