Kingdom of Frost: How the Cryosphere Shapes Life on Earth

Science journalist Vassnes does a wonderful job of discussing how ice has shaped life, and how it is threatened by climate change, in this educational survey. The “cryosphere,” as he describes it, consists of the planet’s areas of frozen water, which represent “35 percent of the Earth’s surface, including around half of the land’s surface.” These range from glaciers and sea ice, to permafrost and the miles-thick ice cap covering Antarctica. Vassnes explains how extreme cold may have impelled the evolution of multicellular organisms and, millions of years later, of genus Homo. More recently, the thousand-year drought associated with the ice age led to the creation of agriculture. Today’s developing climate crisis, he argues, is already being “manifested as a water crisis.” Moreover, melting permafrost has begun to release massive amounts of greenhouse gases, further exacerbating global warming. On the positive, if somewhat counterintuitive, side, he cites research suggesting that reintroducing large grazing animals to the tundra might well slow and possibly reverse this troubling trend. Blending anthropology and history with science, Vassnes offers an alarming but illuminating narrative. (Mar.)