Photo

Photo

Aaron Putnam, a postdoctoral research scientist at the Lamont-Doherty Earth Observatory of Columbia University, is a leader of an expedition to Bhutan to examine links among climate, glaciers and water resources in the Himalaya.

Friday, Sept. 21

Today we set out on what is to be a collaborative, interdisciplinary scientific effort to examine the links among climate, glaciers and society in the high passes of the Bhutan Himalaya.

Nearly 3.2 billion people in South Asia depend on the water that originates from melting glaciers and snowpack of the high Himalaya, yet a gulf of uncertainty hinders our ability to assess the fate of this ice and snow in a warming world. Thus, the goals of this expedition are to collect data that will shed light on the sensitivity of Himalayan mountain glaciers to rising atmospheric temperatures, and to place these glaciers into the context of past climate change.

Our team’s approach is threefold. We will initiate a glacier-monitoring program in an attempt to quantify the response of existing glaciers to ongoing climate change; determine how Bhutan’s glaciers have responded to past climate switches; and reconstruct changes in past temperatures using tree rings, providing us with an independent estimate of climate change to which glacier-based climate records can be compared.

Of course the first major challenge of our effort has been getting to Bhutan, along with overweight luggage filled with sharp ice axes and crampons, massive GPS antennas, rock drills, hammers, chisels and personal cold-weather gear and clothes.

I am traveling with David Putnam, a geoarchaeologist at the University of Maine at Presque Isle, a member of the Bhutan expedition — and also my father. We departed the United States from Newark, headed for Delhi, India. After one night in Delhi we will fly to Thimpu, Bhutan.

For us, the flight path leaving Newark provides a metaphor for our lives and the research that we have undertaken. An hour after takeoff, we flew over our home in far northern Maine, a land shaped by ice sheets, which has in turn shaped us.

After all, my mission is to detect when, how and why climate has changed in the past by inspecting the geologic record of glaciers.

Glaciers are exquisite thermometers. When climate cools, glaciers advance, and when climate warms, glaciers recede, leaving their “footprints” on the landscape. These landscape features allow us to reconstruct the shape and position of former ice tongues, and permit quantification of past atmospheric temperature.

Thanks to recent breakthroughs in a method known as surface-exposure dating, it is now possible to determine precisely how long ago these glacial landscapes were formed, allowing us to develop a detailed chronology of earth’s climate.

To reconstruct patterns of glaciation, I have embarked on field campaigns in interior Antarctica, the Southern Alps of New Zealand, the southernmost Andes of South America, the Rocky Mountains and Sierra Nevada of western North America, the Swiss Alps, the Scottish Highlands, the Tarim Basin of western China and the high Canadian Arctic. Now we go to Bhutan to reconstruct past glaciation and climate in the heart of the planet’s highest mountain range.

From Maine, we continued across the Greenland ice sheet, skirted south of Iceland, and pressed on to fly high above Trondheim, Moscow, Tashkent and Kabul. Our airplane wove through the westerly wind belt from Long Island; across the North Atlantic, the heat pump for the downwind Eurasian landmass; and over the great midlatitude arid belt, where descending air desiccates the land from the Gobi to the Sahara.

After crossing the sand wastes of Uzbekistan and passing over the Hindu Kush of northern Afghanistan, we could see the high peaks of the Karakoram, wrapped in masses of monsoonal cloud off to the east and illuminated by the setting sun.

The flight attendant admonished us to keep the window shade shut because other passengers wished to sleep. I was indignant: “We fly over some of the most spectacular landscapes on earth, and yet we are not permitted to look at them?”

Over the next few weeks, our expedition team of scientists and Bhutanese collaborators, whom I will introduce in detail, will follow the famed snowman trek toward the glacier-covered mountains of Rinchen Zoe La. Our team will share the blue pine forest, wildlife, rivers, mountains and people of Shangri La with you as we meet them, and chronicle all facets of our work.

The face of our planet is etched with imprints that tell the story of responses to climate. The diverse faces of our fellow passengers from Asia, Africa, Europe and North America also reflect those momentous processes that shaped our species.

Few take the time to ponder those profound relationships, and perhaps are told, as were we, to close the shade and let others sleep.