Gretel Ehrlich was living in a tent in Wyoming when her publisher suggested that she write a book about winter, climate change, and global warming. For a year, she traveled from Patagonia in the south to Greenland at the very top of the world. Her findings are not cheery. She sums them up this way: "What follows is both ode and lament, a wild-time song and elegy, and a cry for help — not for me, but for the tern, the ice cap, the polar bear, and the lenga forest; for the river of weather and the ways it chooses to be born." Ehrlich is one of our favorite nature writers (Islands, the Universe, Home, A Match to the Heart) who always has something worth saying about the natural world and the ways we live.

Ehrlich loves the complexities of winter weather and writes beautifully about its white vagrancy and its ability to empty us out: "Winter is a time when we see into things. Once minute, life is so much mush; in the next it comes clear. We break through ice to come on more ice, one translucent door opening onto another. The construct of a single snowflake belies winter's genius: how seeming opacities translate into see-through, cartwheeling membranes that stack up and compress into ice mountains; diamond-hard sparks that slice away self-deception. If blizzards bring on oblivion, their winds also whisk it away. What's left is a swept-out room of stark beauty and clear light."

But now, thanks to human greed and the so-called engines of progress, we may well be bringing this season to an end. In 20 years, there will be no glaciers on the planet and with their loss goes an archive of stories about how living beings evolved, how weather changed, and why plants and animals passed away. For 20,000 years, we have lived in "an interglacial paradise." Now global warming caused by our pollution will likely lead to the loss of a million species of living beings. No wonder Ehrlich agrees with Harvard biologist E. O. Wilson's characterization of human beings as "serial killers."

Read Gretel Ehrlich's lyrical tribute to winter, glaciers, and the artistry of nature and then try to imagine what your world will be like without ice and cold.