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Witness to change

General aviation’s role in documenting climate change in Alaska

Alaska is exponentially busier for general aviation in summer months than winter months.

Documenting climate change in Alaska

Blue pools of the Bering Glacier in southern Alaska from the summer of 2019. According to the National Park Service, Alaska’s glaciers are losing 50 gigatons of ice per year; although they account for about one half of one percent of all glacier/ice sheet cover on Earth, Alaska glaciers contribute about 9 percent of total ice melt. Paul Claus Ruth Glacier Alder Creek, 2019: Photographs of Ruth Glacier Alder Creek, 20 years apart (this and following image)Brian Okonek. Ruth Glacier Alder Creek, 2000: Brian Okonek photographed the Alaska Range throughout his extensive mountain guiding career. Brian and his father, Jim Okonek, took many flights together studying the glaciers. Over time, the Ruth Glacier receded and the lake here drained. Upper Barnad Glacier, Wrangell Mountains: Bushwheels have made glacier landings possible for highly skilled pilots who enjoy exploring the glaciers in the summertime. This is Upper Barnard Glacier in the Wrangell Mountains. Paul Claus Yahtzee Glacier: Glaciologist and expert of ice core studies Chris Larsen does field research on the Yahtzee Glacier near Icy Bay of the St. Elias Mountains. Larsen has studied ice core samples from around the world. Paul Claus Spruce Beetle Kill at the toe of Kahiltna Glacier: While foresters have associated the beetle kill outbreaks in Alaska with warmer winters, it has yet to be claimed to be caused by climate change. Tokosha mountains: An aerial view of the Tokosha Mountains and Ruth Glacier shows the walls of the glacier losing elevation. Pilot Paul Roderick said the lower half of Ruth Glacier appears to have lost 20 feet in elevation in 20 years, with upper areas of the glacier losing 5 feet. Midway point of Ruth Glacier: This image shows shrinkage of the glacier ice where new streams form every year that eventually drain into the Ruth River and then the Chulitna River. This large-scale melting adds to the high water events on the Chulitna River that drains into the Susitna River.

The long days of sunlight provide a longer window to fly. Outdoor tourist attractions include fishing trips to remote lodges, bear viewing, and scenic glacier flights—all requiring an airplane ride. In addition to year-round Alaskan aviators, “snowbirds” return to enjoy the freedom of flying over a stunning landscape of big rivers, clear lakes, and massive mountain ranges. During the summer of 2019, however, record-breaking heat and unprecedented drought created conditions uncharacteristic for South Central Alaska. For anyone who views the landscape from the aerial perspective, the changes have noticeably accelerated in the past five years.

In South Central Alaska, there are widespread fire scars near Willow from the Sockeye Fire of 2015 as well as the McKinley Fire of 2019. The spruce beetle outbreak has turned the forest from healthy green to a dead, rusty brown and continues to challenge utility companies and landowners in clearing dead trees.

On July 4, 2019, Anchorage saw the thermometer reach 90 degrees Fahrenheit for the first time in recorded history. Shortly after this record, the Chulitna, Talkeetna, and Susitna rivers were near flood stage caused by runoff from melting glaciers. Then came the wildfires. The McKinley Fire attracted national attention. Many flightseeing companies had to cancel flights because of the smoke-filled air.

General aviation pilots can play a role in witnessing changes to the environment and providing valuable data to climate scientists. One method of gathering information on weather in Alaska has been FAA webcams that are designed to give pilots visual weather information to help inform their “go/no-go” decision. About half of these cameras are colocated with weather stations that supply temperatures, dew point, wind, and altimeter settings included in METARs. Also, the information gathered at airports in Alaska and worldwide has provided valuable data used by weather forecasters to see trends and make comparisons.

Climatologists such as Brian Brettschneider of the University of Alaska Fairbanks utilize data collected from FAA weather camera sites for their graphs, maps, and mosaics which in turn help them not only forecast weather, but keep track of climate. Brettschneider also studies the comments and data from pilot reports, which hold a tremendous value not only to pilots, but for the study of climate.

Original by Rick Thoman, re-created with permission
Original by Rick Thoman, re-created with permission

“Those are really helpful for getting a feel for the vertical structure of the atmosphere,” Brettschneider said.

Brettschneider says that he’ll download the entire list of pireps nationwide to take another look at climate. With commercial aviation, the large aircraft are sending temperature, wind, and atmospheric information that is becoming part of large computer models.

“Anything that we can get from that third dimension is really helpful,” Brettschneider added.

View from above

Glaciers are one of the harbingers of climate change. In Alaska, they are melting quickly and the aerial evidence is shocking. The glaciers are melting at an unprecedented rate that is startling to scientists who have been studying ice core samples from glaciers in the Alaska Range.

Erich Osterberg, an associate professor of Earth sciences at Dartmouth College, has been studying ice core samples of the Alaska Range for more than a decade.

Osterberg and fellow researchers have tracked temperatures in the Alaska Range at 14,000 feet to demonstrate a 3 1/2 degree Fahrenheit increase in temperature over the past 400 years, based on the information detected in the ice cores.

“We see a 60-fold increase in summer melting happening on the Hunter plateau today compared to approximately 150 years ago,” Osterberg said. The average July air temperature at Denali base camp on the Kahiltna glacier is 36.9 degrees F, but on that scorching July 4 day in the summer of 2019, it reached a whopping 50 degrees F.

Climate change has slowly become a topic of high priority. But is it a comfortable conversation? The answer depends on who is sitting at the table. The more reliable the information, the better.

Some of the most valuable tools for educating people on the changes happening to the landscape are photographs. The bird’s-eye view of pilots can provide invaluable evidence of the changing landscape that includes melting glaciers, beetle kill, wildfires, and riverbank and coastal erosion. All of these visual changes are being exacerbated by climate warming.

“It’s hard to argue against a photograph,” Brettschneider said. “A photograph is a photograph. It’s a monument of time that really can’t be disputed.”


Photographs document what long-time Alaskan pilots have witnessed for decades. Jim Okonek, who is now in his eighties, has a wealth of knowledge from flying in the Alaska Range. He was a previous owner of K2 Aviation and has been flying around the state since the 1970s. He says that a big change he has seen is on the lower Ruth Glacier, north of the Bubbling Springs near the terminus, where there used to be a lake on the lower glacier on the southeast side that has since drained. 

“There used to be a lake that drained out of the glacier, and the river runs underneath the ice,” he said. “The river that came out of there did not appear as a river until about two to three miles down to the Tokositna River. Then, it was running underneath the ice. But now, the glacier melted back.”

Photographs of the Lower Ruth Glacier illustrate the greenery Okonek describes.  

“The glacier has melted back enough that there is vegetation on top of the ice, a small young forest. All of that soil on top of [the] glacier is from wind-blown sediments from Broad Pass.

“That is a strange phenomenon,” he said. “Wind is carrying glacier silt from rivers and vegetation is now growing on top of the glacier. That is likely from the warmer temperatures we are experiencing from the summers.”

Talkeetna Air Taxi owner/operator Paul Roderick, a world-renowned pilot who has flown thousands of hours in the Alaska Range, pointed out that the lower half of large glaciers­—including the Ruth, Tokositna, and Kahiltna glaciers—are not moving as they had in the past. He sees them melting at a fast rate and, in many places, collapsing.

Roderick added that the landing zones in the Alaska Range that air taxis have used for more than 50 years are developing crevasses and becoming unstable. “Approaches to some of the climbing routes are more difficult to access due to glacial recession and crevassing,” he said. “The climbing season has been narrowing for the last 30-plus years. In the 1960s and ’70s, most expeditions climbed through July and even into August. Now, we try to pull everyone out by mid-July.”

During the record-breaking heat of July 4, 2019, Kahiltna base camp temperatures changed the takeoff and landing zones. The snow became soft and sticky, making it difficult to take off. Roderick added, “The melt rate of the snow on the glacier was certainly extremely high and caused many massive rock and ice avalanches from high elevation.”

The Talkeetna flightseeing business had one of its busiest seasons in the summer of 2019 because of the record number of clear skies and flyable days. While some may think, are these air tours adding to the carbon footprint? they also provide a hands-on experience to witness the glaciers’ unprecedented rate of melting, which is backed up by scientific evidence of ice core studies. 

“Passengers over the last five years are much more accepting of climate change and before we even mention this subject on the tour, we are often asked about climate change,” Roderick said. “It’s sobering for many to show them the physical evidence of lateral moraine depths and large melt pools that did not exist just a year or two ago. Also notable changes are fern line elevation increases and large amounts of rock fall from thawing above 10,000 feet. All of these changes are real and easy to see, which convinces our passengers [of] the reality at hand.” 

Legendary bush pilot Paul Claus of Ultima Thule Lodge, which is located on the banks of the Chitina River in the Wrangell-St. Elias National Park , says that the most common question from lodge guests is about the changes in the glaciers. Claus has flown scientists around a huge area of North America, ranging from the mountains of British Columbia to the far stretches of the Aleutian Islands. He also works closely with NASA as well as glaciologist Chris Larsen. Larsen and Claus have spent countless hours in an airplane together flying back and forth to study sites. Do they agree on the study of climate change? Certainly not, and that keeps both of them on their toes when it comes to backing up their different belief systems.

“First of all, I live in probably one of the most dynamic places there is on the planet,” Claus said. “It’s always changing. There’s changes going on all the time. So to say what’s [changed] the most, and I’ve seen huge mountainsides collapse with billions of tons of material come down and change the whole face of a mountain. I’ve seen how glacial terminus has changed. But you know, things are always changing. So it’s a very, very dynamic place to put up to quantify what’s the most, I don’t know if I can do that.” For glacier pilots, the day-to-day decision of landing zones is also very dynamic. “You got to be flexible to go to different places,” Claus said.

Observations from pilots such as Jim Okonek, Paul Roderick, and Paul Claus are not recorded as scientifically as those of Brian Brettschneider, Erich Osterberg, and Chris Larsen. Yet, general aviation pilots’ observations of the Earth hold tremendous value that adds to the climate change conversation.

Whether you are an aviator, a weather forecaster, a climatologist, or a photographer, these groups can combine their various levels of expertise and “eyes above the ground” in the study of climate change. In addition, the collection of weather data that has been important for the safety of pilots can also play a bigger role in the study of climate. With all of us working together, collecting data and sharing information, we can find solutions to adapt and respond to global changes with greater efficiency.

Katie Writer is an Alaska pilot and journalist who enjoys documenting the seasons from her Piper Super Cub. In addition to journalism, she’s also passionate about photography, art, and the environment.

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