“Hold the shotgun and watch out for polar bears.”
John Lenters pushed a metal boat into a freshwater lake three miles south of Barrow and motioned for me to climb aboard. The wind was stiff, the sun bright, the vista dotted with Arctic flowers—marsh marigold and Arctic cotton. Lenters, a hydroclimatologist at the University of Nebraska, studies how tundra lakes are responding to climate change. Now he was steering toward a yellow speck in the middle of the lake, a climate-monitoring buoy due for scheduled maintenance.
The tundra is a vast watery wilderness filled with snaking rivers and tens of thousands of elliptically shaped lakes supporting moose, caribou and polar bears. From the air, with its clouds and mist, it looked, oddly enough, more like the Amazon basin than the desert that one of Lenters’ colleagues called it and by some definitions it is. (Lenters himself says only that “precipitation is slight.”) But what precipitation there is, Lenters explained, is prevented from seeping into the soil by permafrost, the layer of frozen earth that begins about two feet beneath the surface and goes down, in North Alaska, some 2,000 feet. Globally, permafrost holds an estimated 400 gigatons of methane, one of the greenhouse gases that is hastening the earth’s warming. As the permafrost thaws—which it has begun to do—lakes can drain away and the thawed soil can release billions of tons of methane into the atmosphere.
Lenters pulled up to the buoy and, balanced on the prow of the boat, began wrapping duct tape around some of the buoy’s wires to protect them. “This is the grunt work of science,” he said. A swiveling arm on the buoy measured wind speed. Solar panels on its three sides provided power. A glass-domed instrument on top registered incoming infrared radiation to monitor the greenhouse effect—the rise in temperature that results from the trapping of heat by certain gases, such as carbon dioxide, in the atmosphere.
Lenters said that he and other researchers—aided by decades-old satellite images as well as consultations with Inupiat—are visiting tundra lakes all over the area, walking their perimeters and measuring their size, water depth and temperature. “Everything up here is related to climate change,” Lenters said, “but to understand it you must learn the underlying dynamics.”
In his camouflage clothes and waders, Lenters looked like a deer hunter as he jury-rigged repairs and took measures to protect the buoy from various assaults over the next ten months. Windblown chunks of ice might partially submerge it, and once the lake freezes over, a curious Arctic fox might nibble on its wires. While tending the buoy last year, Lenters spotted two polar bears a quarter-mile away swimming toward him. Bears are an ever-present concern. Guards with shotguns sometimes stand watch at high- school football games. (While I was in Barrow, a bear wandered past BASC headquarters. Another took pieces out of a scientist’s boat; no one was inside.) While Lenters worked, I scanned the horizon.
Lenters said that while he’d collected only about a year’s worth of data, he’d already been surprised by it. Typically, he said, lake beds release as much heat into the water in the winter and spring as they absorb in the summer and fall. This balance keeps the annual sediment temperatures fairly stable. “But what we found was that heat was going into the lake sediment almost all year long.” It’s too soon to draw any firm conclusions, he added, “but the water temperatures are out of equilibrium with the lake sediment, causing a nearly continuous thawing of the underlying permafrost. The lake is out of whack.” Then he turned the boat around and we headed back to town for some hot soup.
Bowhead whales are named for the massive bony skulls that enable them to break through ice to breathe. They can live up to 200 years; adults weigh up to 100 tons. Their biannual migrations between the Bering Sea and the Eastern Beaufort Sea carry them past Barrow each fall and spring. “The whale is central to our culture,” Mayor Itta had told me. “The warmer ocean and currents will markedly shorten our spring whaling season.” He was concerned about possible changes in whale migration patterns and sea ice conditions; hunters must travel over ice to reach whales. “The impacts are around us already. We need more baseline science so we can measure these impacts over time.”
Which was one reason that—about 20 miles out to sea—Eskimo whalers and researchers aboard three small boats rode the chop, looking to tag bowheads with radio devices. Mark Baumgartner, a biologist from the Woods Hole Oceanographic Institution in Massachusetts, was looking for answers to the same questions as the whalers with him. “We think the environment is going to change,” he said. “We don’t exactly know how. This is part of a study to learn how the animals forage and how food is organized.” If warming seas cause the whales’ preferred foods to move, the whales could follow—with disastrous consequences for Eskimos.
Carin Ashjian, another Woods Hole biologist, was on a sister ship, the 43-foot-long Annika Marie, studying krill, a shrimplike animal that bowheads eat. Massive amounts of krill pile up on the continental shelf off Barrow each year in the fall. The krill are pushed by sea currents and wind, both of which can be affected by weather patterns. “We want to know whether there will be more or less krill with climate warming,” Ashjian explained. She said her five-year-old study was still too new to yield any firm conclusions: “The Arctic is changing so fast that when it comes to learning basics, we may have started too late.”