Permafrost–permanently frozen ground that lies under tundra and boreal forests across the Arctic–covers more than 12 percent of the earth’s land.  In The Big Thaw, readers meet scientists and students who have been studying the permafrost and what it contains: a vast store of ancient carbon, more than four times the quantity found in all of today’s forests, a ticking “carbon bomb” releasing carbon dioxide and methane as the permafrost thaws. Braving hordes of mosquitoes, quicksand, and extreme temperatures, the researchers are racing against the clock to educate us about the changes we must make to preserve Earth’s carbon balance.  In this talk, photographer Chris Linder will share behind-the-scenes stories from his eight field seasons photographing scientists at work in Siberia and Alaska.