"Worldwide, glaciers are on the wane. As a result, the albedo effect — the ability of ice and snow to deflect heat back into space — is declining as glaciers melt and less and less snow covers the ground each winter. Snow and ice are the Earth's built-in air conditioner, crucial to the health of the planet. Without winter's white mantle, earth will become a heat sponge, and only smoke from a volcano could shield us from incoming UV rays. As heat escalates, all our sources of fresh water — already in danger of being depleted — will disappear. . . .

"Everything is always becoming something else. But glacier ice goes only one way: toward more ice, or ice that is becoming water — because ice never reverts directly back to being a snowflake. In Japan's snow country, people say that ice and water are yin — female — and snow is yang — male; that a glacier starts out masculine but quickly becomes a moving giant of femininity.

"Ice comes from water but can teach water about cold, the poet Muso Soseki says. After, it goes back to being water again. A glacier's fenders and underpinnings can move at different speeds, yet it appears to be a single mass. In midsummer crevasses deepen and meltwater ponds can split open. The fissures cut straight down, and the turquoise eyes drain. This is water teaching ice how to become water.

"A glacier is a kind of blind eye. It can hoard snow without seeing how big its own body is getting. And it can give away more than it takes in. Is this compassion or self-loathing? What makes it act this way? For a glacier, the first law of impermanence is: something has to give.

"A glacier is an archivist and historian. It saves everything no matter how small or big, including pollen, dust, heavy metals, bugs, bones, and minerals. It registers every fluctuation of weather. A glacier is time incarnate, a moving image of time. When we lose a glacier — and we are losing most of them — we lose history, an eye into the past; we lose stories of how living beings evolved, how weather vacillated, why plants and animals died. The retreat and disappearance of glaciers — there are only 160,000 left — means we're burning libraries and damaging the planet, possibly beyond repair. Bit by bit, glacier by glacier, rib by rib, we're living the Fall.”