Once you get the job as a diplomat, you'll be paid by the Foreign Service, and you'll be issued a "class" and a "step" depending on your level of education, skills, experience in the real world and the type of job you’ve accepted.
A newly-minted diplomat can be paid as little as $30k and as much as $200k+. And while that first number is pretty darn low, keep in mind that your living, transportation, and other daily expenses will be paid by the U.S. government. Once you start to gain more experience and knowledge, you'll be moved up classes and steps and begin to earn more. There is a cap on diplomatic salaries depending on where you are; diplomats living in Washington, D.C. may make more money than one in Afghanistan. Again, it all depends on your locale.
Greenland. Bring a jacket.