Climate Change in the High Arctic: Lake Hazen’s Response

High above the Arctic Circle, far from the footprint of human civilization, a significant indication of human-induced climate change has manifested in Lake Hazen, the largest lake by volume north of the Arctic Circle. The lake and surrounding glacial environment are experiencing rapid change as the climate warms, ice cover declines, and glaciers retreat. A recent study in Nature Communications examines these physical drivers and their impacts on the lake’s ecological composition and the physiological condition of its only fish species, the Arctic Char. These changes, unprecedented in 300 years, have serious ramifications for local indigenous populations who rely on the lake’s ecosystem services.

Map of Lake Hazen watershed
Map outlining the Lake Hazen watershed and changes in surrounding glacier surface temperatures from 2000 to 2012 (Source: Lehnherr et al.).

In northern Ellesmere Island, the farthest north of the islands that compose the Canadian Arctic Archipelago, summer air temperatures increased by 1 degree Celsius during the 2001 to 2012 period in comparison to the period 1986 to 2000. Climate model simulations suggest temperatures are expected to increase 3.2 degrees Celsius by 2100. These changes have the potential to dramatically alter local ecosystems.

The study’s research team, which included experienced Arctic scientists from a diverse set of backgrounds, grew over time, according to Igor Lehnherr, who spoke with GlacierHub. From a scientific standpoint, the team knew that glacial masses were shrinking in other parts of the Arctic, along with summer lake ice cover. From this basis, according to Lehnherr, it was ”a matter of bringing everyone on board with all the different expertise required to quantify each of these various aspects.”

The study’s authors note that few previous studies have evaluated ecosystem-scale changes to climate change in inland watersheds. Lehnherr cited the need for a multidisciplinary team and baseline data to “quantify how much the system has changed and what drivers are responsible for ecological change” as challenges to study.

Photo of Eureka Sound on Ellesmere Island
Eureka Sound on Ellesmere Island (Source: Stuart Rankin/Creative Commons).

The researchers benefitted from over 50 years of scientific research on Lake Hazen, helping this recent study fill part of this knowledge gap by analyzing how the lake’s ecosystem has responded to climate change. The study does this through four distinct, yet interconnected focuses: watershed warming and declining lake ice cover, hydrological changes within the watershed, recent changes in the paleo-lake record, and ecological shifts in the lake itself.

Watershed Warming and Declining Lake Ice Cover

From 2000 to 2012, summer air temperatures in the Lake Hazen watershed rose by 2.6 degrees Celsius, with most of the rise occurring after 2007. These higher air temperatures, in turn, warmed the soil. Spring-time soil temperatures were 4 degrees Celsius higher from 2007 to 2012 than they were from 1994 to 2006. The lake warms particularly in late spring, when it is still covered by ice, and in early summer, when ice cover finally breaks up. Overall, the lake’s warming trend is causing ice to melt earlier in the summer and freeze later in the fall. This is in addition to an increase in ice-free area by 3 km2 per year since 2000, which was found to be related to August lake surface temperatures.

Hydrological Changes within the Watershed

Glaciers within the Lake Hazen watershed are the main hydrological driver. Because of warming temperatures, these glaciers are experiencing mass-balance losses. Positive feedback loops play a role in this loss, as high surface temperatures melt ice, subsequently decreasing reflectivity, which allows the surrounding surface to absorb more solar radiation, speeding up melting.

Figure detailing trends in lake surface temperatures, onset dates for ice melt and freeze up, and ice cover.
Figure detailing trends in lake surface temperatures, onset dates for ice melt and freeze up, and ice cover (Source: Lehnherr et al.).

Mean rates of annual glacial runoff have increased significantly in recent years. This increase has raised water levels in Lake Hazen by almost a meter since 2007. Finally, the large increase in glacial runoff into Lake Hazen has lowered the time that water stays in the lake (before leaving by the lake’s one outflow stream) from a historical average of 89 years to 25 years today.

Recent Changes in the Paleo-Lake Record

The increase in glacial runoff entering Lake Hazen has driven sediment accumulation rates to levels eight times higher than a 1948 baseline period. Most runoff is deposited by glacier-fed rivers that empty into the lake, leading to the increased mixing and oxygenation of the lake’s once stable and anoxic bottom waters.

More sediment deposition has also given rise to increased levels of anthropogenic contaminants, such as mercury and pesticides, in lake sediments. In addition, organic carbon accumulation rates in the lake have increased by an astonishing 1000 percent, much higher than the 50 percent increase in most North American boreal lakes.

Ecological Shifts

To assess the impact of the lake’s changes outlined above on its ecology, the authors used micro-fossil counts of algae. Before widespread warming (prior to 1890), when the lake was covered with ice almost year-round, algal fossils were rare. However, after warming (post 1890), when more areas of the lake became ice-free, nearshore algal species boomed.

After remaining relatively stable for much of the 20th century, the lake’s ecological composition changed in the late 1980s when planktonic species succeeded benthic species. This change was driven by a longer ice-free period where the deep waters of the lake were exposed to light for more months each year.

Photo of Lake Hazen
Lake Hazen (Source: Igor Lehnherr).

Lake Hazen’s one fish species, the Arctic Char, has also been negatively impacted by climate warming. Lehnherr notes that the team might have expected ice-free summers to increase the lake’s primary productivity, subsequently increasing biomass and leading to healthier and thriving Char populations. However, this has yet to occur; instead, amplified lake turbidity due to the raised levels of glacial river discharge has hindered the ability of the visually reliant Char to feed on midges and other Char, harming their physiological condition.

Implications

These changes have negative effects on the lake’s ecology and also on indigenous communities that inhabit the area. These communities rely on the lake as a source of food in an otherwise desolate region. While the future of High Arctic ecosystems is far from certain, Lehnherr points to the need for more multidisciplinary studies that encompass entire watersheds as a key to the better assessment of climate change impacts.

Cape Farewell and The Farewell Glacier

Artist David Buckland cares deeply for the health of the planet and believes the rest of the world should care as well. In 2001, he founded the Cape Farewell Project, an international non-profit based at the University of Arts London in Chelsea. He recently co-authored an article titled, “The Cultural Challenge of Climate Change,” along with authors Olivia Gray and Lucy Wood, which provides his reasoning for launching Cape Farewell. He hoped his nonprofit would spark a cultural reaction from artists, scientists and educators on the impacts of climate change. Cape Farewell has accomplished this goal many times over.

Beginning in 2003, Cape Farewell has invited educators, scientists and artists to voyage to the Arctic, the Scottish Islands, and the Peruvian Andes, to comment on what they see and experience. As Cape Farewell’s website highlights, “one salient image, a novel or song can speak louder than volumes of scientific data and engage the public’s imagination in an immediate way.” Cape Farewell’s ultimate goal is to elicit a human response to climate change, by engaging the public to build a more sustainable future, one that is less dependent on fossil fuels. To date, 158 artists, including film-makers, photographers, songwriters, novelists and designers have journeyed with Cape Farewell.

David Buckland deciding on the sailing route. (Source: Cape Farewell).
David Buckland deciding on the sailing route (Source: Cape Farewell).

One such artist is Nick Drake, a poet, screenwriter and playwright, who recently wrote the poem “The Farewell Glacier” in response to a 2010 Cape Farewell expedition to the Arctic. From Drake’s perspective, a more sustainable future involves taking action before this ecosystem disappears forever. His first expedition (and Cape Farewell’s ninth), led him to Svalbard in Norway on a ship named the Noorderlicht, for 22 days. He was exposed to the threatened environment, examined retreating glaciers, and explored scientific research about the region. Research is conducted aboard the ship during each expedition.

In this excerpt from Drake’s poem, he calls on the other artists not to forget what they witnessed in the Arctic:

 

Farewell 3

 

Drake also states, “Sailing as close as possible to the vast glaciers that dominate the islands, they saw polar bear tracks on pieces of pack ice the size of trucks. And they tried to understand the effects of climate change on the ecosystem of this most crucial and magnificent part of the world.” His poem portrays the urgency of the “climate challenge.”

Ecotourism_Svalbard
Ecotourism at Svalbard in Norway (Source: Woodwalker/Creative Commons).

Two films were also spawned from the Project – “Art From the Arctic” and “Burning Ice.” Both films visually represent some of the Cape Farewell journeys to the High Arctic. “Art From the Arctic” was seen by over 12 million viewers. All the artwork that stems from Cape Farewell expeditions is expected to inspire a public conversation around climate responsibility. Other works generated from Cape Farewell expeditions include exhibitions such as “u-n-f-o-l-d,” an exhibit featuring twenty-five creatives who sailed to the High Arctic, and music festivals such as “SHIFT,” an eight-day music and climate festival held in London’s Southbank Centre.

Svalbard, Longyearbyen Isfjord (Source: Banja&FransMulder/Wikimedia Commons).
Svalbard, Longyearbyen Isfjord (Source: Banja&FransMulder/Creative Commons).

As these voyages occur, the public is kept abreast virtually, through expedition blogs by the artists. The first expedition began with a journey to Svalbard in the High Arctic, chosen as a starting place because of the visible impacts of climate change on the scenery and wildlife, with climate change in the Arctic occurring more rapidly and severely than in other regions of the world.     

Cape Farewell is continuing its mission to engage the public in climate change discussions, with each work created to inspire others to work toward a healthier environment. Current projects include “Space to Breathe,” a response piece to air pollution in urban settings. You can track Cape Farewell’s progress on their website and follow them on twitter @capefarewell.

Listen to Nick recite his poem “The Farewell Glacier” below:

Roundup: Sediments, Swamps and Sea Levels

Roundup: High Arctic, Peru, and Global Seas

 

Suspended Sediment in a High-Arctic River

From Science of The Total Environment: “Quantifying fluxes [the action of flowing] of water, sediment and dissolved compounds through Arctic rivers is important for linking the glacial, terrestrial and marine ecosystems and to quantify the impact of a warming climate… This study uses a 8-years data set (2005–2012) of daily measurements from the high-Artic Zackenberg River in Northeast Greenland to estimate annual suspended sediment fluxes based on four commonly used methods: M1) is the discharge weighted mean and uses direct measurements, while M2-M4) are one uncorrected and two bias-corrected rating curves extrapolating a continuous concentration trace from measured values.”
 
Read more about suspended sediment fluxes here:
 

View of the Zackenberg River and Zackenberg Research Station (Source: Moser på Nordøst-Grønland/Creative Commons).
View of the Zackenberg River and Zackenberg Research Station (Source: Moser på Nordøst-Grønland/Creative Commons).

 

Glacier Recession in Cordillera Blanca

From Applied Geography: “Receding mountain glaciers affect the hydrology of downslope ecosystems with consequences for drinking water, agriculture, and hydropower production. Here we combined land cover derived from satellite imagery and other environmental data from the northern Peruvian Andes into a first differencing regression model to assess wetland hydrologic connectivity… The results indicate that there were two primary spatial driving forces of wetland change in Peru’s Cordillera Blanca from 1987 to 1995: 1) loss in glacier area was associated with increased wetland area, controlling for other factors; while 2) an increase in mean annual stream discharge in the previous 12 months increased wetland area.”
 
Learn more about the study here:

 

View of mountainside of Cordillera Blanca, Peru (Source: MacDawg/Creative Commons).
View of mountainside of Cordillera Blanca, Peru (Source: MacDawg/Creative Commons).

 

Observation-Based Estimates of Glacier Mass Change

From Surveys in Geophysics: “Glaciers have strongly contributed to sea-level rise during the past century and will continue to be an important part of the sea-level budget during the twenty-first century. Here, we review the progress in estimating global glacier mass change from in situ measurements of mass and length changes, remote sensing methods, and mass balance modeling driven by climate observations. For the period before the onset of satellite observations, different strategies to overcome the uncertainty associated with monitoring only a small sample of the world’s glaciers have been developed. These methods now yield estimates generally reconcilable with each other within their respective uncertainty margins. Whereas this is also the case for the recent decades, the greatly increased number of estimates obtained from remote sensing reveals that gravimetry-based methods typically arrive at lower mass loss estimates than the other methods. We suggest that strategies for better interconnecting the different methods are needed to ensure progress and to increase the temporal and spatial detail of reliable glacier mass change estimates.”
 
Read more about global sea-level rise here:

 

Calving front of the Upsala Glacier, Argentina (Source: NASA/Creative Commons).
Calving front of the Upsala Glacier, Argentina (Source: NASA/Creative Commons).