By Michael Gerrard
By Fred Pearce
By Chloe Williams
By Katherine Bagley
By Rene Ebersole
By Bill McKibben
By Jim Robbins
By Beth Gardiner
By Paul Hockenos
By Daniel Munczek Edelman
By Nicola Jones
By Stephen J. Pyne
By Michael Standaert
By Mario Alejandro Ariza
By Ed Struzik
By Jennifer Oldham
By Glenn Hurowitz
By Peyton Fleming