Overview
Choose one of the topics we’ve covered and write a thoughtful term paper. This will serve as your final evaluation. Provide at least four full citations (not just URLs). It doesn’t matter what format you use, so long as you are consistent. The resulting paper’s text should be at least four pages long, easily more. Use the same font and spacing as for the homework, please. You may also include graphics and extended quotations if you provide citations. I encourage you to produce some of your own graphics if you are so inclined. You will find these to be useful if you upload your work to Portfolium. There is no upper limit to the length of the paper, but please don’t artificially lengthen it with unnecessary repetition. I expect all of you to produce a paper that you can publish online without further editing.
Optional topics：
1. Lithium, cobalt, and rare earths
2. Uranium, thorium, and plutonium
3. The Oceans
4. The Lithosphere
5. Ecosystems
6. The Biosphere
7. Climate
8. The Hydrosphere
9. Sensing and modeling
10. The Atmosphere
11. Coronal Mass Ejections
12. Energy and the Sun-Earth system