In 1941, an Italian civil servant named Felice Benuzzi was captured by Allied forces and sent to a prisoner-of-war camp in East Africa. The camp faced Mount Kenya, 17,000 feet high, and Benuzzi found himself staring longingly at that larger, snow-blanketed world from the smallness of his own. Eventually he couldn’t help himself; he decided to climb the mountain.

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[/one_fourth][three_fourth_last]It’s important to know two things about the adventure that followed, which Benuzzi chronicled in his book, “No Picnic on Mount Kenya.” First, Benuzzi did manage to escape the camp and climb to the summit of the mountain’s third-highest peak. (He and two other prisoners spent eight months clandestinely preparing: They made ice-climbing gear from barbed wire, and because they didn’t have a map of Mount Kenya, they consulted an illustration of it on a brand of canned food.) Second, when Benuzzi came back down, after 18 days on the mountain, he apparently felt so rejuvenated — as if he had absorbed enough beauty to sustain him — that he decided to sneak back into the camp and picked up his life again as a prisoner. The mountain was that large and impressive, that sublime.

This past October, the English photographer Simon Norfolk spent 18 days on Mount Kenya, camping in an old mountaineering hut at nearly 16,000 feet. Norfolk was there to document the gradual disappearance of one of the mountain’s many glaciers, the Lewis, which happens to be one of the most thoroughly surveyed tropical glaciers in the world. Its ice mass has been mapped periodically since 1934, and in recent decades, as the earth has warmed, scientists have reported on its catastrophic recession in their own quiet, peer-­reviewed way. In 1979, for example, glaciologists mapped the Lewis from an airplane and discovered ‘’drastic ice loss’’ since the last mapping four years earlier. In 1983, another survey found the same thing. There was similar bad news in a 1995 study (“climatic forcing of the glacier recession has accentuated in recent years”) and, likewise, a decade after that (“a drastic and progressive shrinkage.”) In 2010, scientists found that the Lewis had shrunk by 23 percent in just the previous six years. Worse still, a neighboring glacier — the Gregory — “no longer exists.”

Norfolk was disturbed that the death of something so large could be taking place so stealthily. It was happening over the course of so many human generations that it was essentially invisible to any one of them. He trekked to the Lewis Glacier because he had come up with a way to reveal its drama, to burn right through the problematic lag between glacial and human time scales. In these photographs, he has used fire to draw the former boundaries of the ice. Collaborating with a nonprofit organization called Project Pressure, he overlaid GPS coordinates onto that historical data about the Lewis Glacier’s size and shape. This allowed him to plot out the vanished edges of the glacier on the actual landscape. He then slowly walked those lines, in the middle of the night, with a makeshift torch: a length of shaggy white carpet rolled into a wick, soaked in gasoline, strapped to a garden rake.

It was so cold, and the air so thin, on the mountain that even walking with his fire-rake for 20 minutes exhausted Norfolk completely. He was like a man lost on an island, pacing and waving a flame for help. But his camera, set for an exposure of an hour or more, captured his movement as a solid line of fire: a burning scar.

Norfolk knew and loved the story of Benuzzi’s climb up Mount Kenya, but he got a very different feeling from the place. The mountain didn’t seem overwhelming or otherworldly now, but rather broken and vulnerable. As Norfolk worked, he could hear meltwater rushing down the glacier’s flanks. Standing next to that ice field, he says, was like standing next to “the exhausted remains of something that was once glorious.” He thought of nature documentaries, of scenes in which, say, a bull elephant is tranquilized by a researcher and crumples on the ground. “You can approach it now, because it’s safe,” Norfolk says. “But you feel its desperateness, as if it is opening one eye and looking back at you, saying, ‘What have you done to me?’ ”

Most of us have probably never felt so indicted, so directly, by melting ice. Glaciers can feel like far away, abstract things — even in places like my home, San Francisco, that partly rely on them for water. Our glaciers, we’re told, are disappearing freakishly fast, but fast for a glacier can still be too slow for the human imagination to seize on. They’re like a lot of environmental problems that way: all these monstrous leaky faucets, on other floors of the house, that we know we ought to get around to fixing. The challenge, right now, is to find a way to make the slow deterioration of the world’s beauty feel as urgent and overpowering from afar as the beauty itself did to a man like Felice Benuzzi.