If you are interested in what you can do for the climate, we need all the help we can get. Our code may not be the epitome of hygiene (think decades-old python with docstrings that haven't been touched in that long), but in the time I've been here we've gotten loads better. All of our code lives on github ([4] and [5]), we have way more funding than we know what to do with, and we have more work to do than people to do it.
If you're interested, shoot me an email (in my profile). I'm still hunting for the job application link.
EDIT: Job link found! http://careers-ext.llnl.gov/jobs/4494026-software-developers... Don't worry about all of the skills listed, it's a generic one. Feel free to shoot me an email if you have any questions.
[1]: https://www.llnl.gov [2]: http://climatemodeling.science.energy.gov/projects/accelerat... [3]: https://en.wikipedia.org/wiki/Program_for_Climate_Model_Diag... [4]: https://github.com/ESGF [5]: https://github.com/UV-CDAT