The second of three panels from contributing authors to the book Earth 2020: An Insider's Guide to a Rapidly Changing Planet discuss the state of the planet on the 50th anniversary of Earth Day. Participants include Sally Aitken, UBC; Doulas MacMartin, Cornell; Roland Geyer, UC Santa Barbara, and U. Rashid Sumalia, UBC
![](https://i.ytimg.com/vi/n3t-AyUXgMY/maxresdefault.jpg)