Edited by Renata Leite Pitman, some rights reserved (CC BY-SA)
Photo Credits
- 1. (c) Steven Severinghaus, some rights reserved (CC BY-NC-SA)
- 2. (c) eyeweed, some rights reserved (CC BY-NC-ND)
- 3. (c) btanderson, some rights reserved (CC BY-NC), uploaded by btanderson
