Permafrost, subsurface soil that remains frozen throughout the year, can be found on Alaska’s North Slope and in places across the Arctic. “The temperature of permafrost is rapidly changing,” said Vladimir Romanovsky, Geophysics professor and head of the Permafrost Laboratory at the University of Alaska Fairbanks Geophysical Institute.
In the very near past when Vladimir Romanovsky was asked to predict what will happen to permafrost he’d have noted that North Slope permafrost is very cold. “During this century, nothing would happen. That’s what I would say about 5 years ago. Well, I cannot say it anymore.”
“For the last 30 years, the mean annual ground temperature at the top of permafrost on the North Slope has been rising,” Romanovsky reported. At a measurement site in Deadhorse the average (mean) annual ground temperature in 1988 was 17.6°F (-8°C). Now it’s 28.5°F (-2°C). Looking at a graph of Deadhorse temperatures, Romanovsky described “The warming of permafrost is following warming in air temperatures. So the main forcing which made permafrost warmer on the North Slope of Alaska is an increase in air temperature.”
Romanovsky and team members University of Alaska Fairbanks Geophysical Institute scientists Dmitry Nicolsky, reserach assistant professor, and Santosh Panda, research associate, presented at the 2015 American Geophysical Union Fall Meeting, a gathering which brings together over twenty thousand. scientists in the Earth and space science fields.
They reported: new projections of permafrost change in Alaska’s northern reaches suggest far-reaching effects will come sooner than expected.
One of the tools used to study permafrost is the Geophysical Institute Permafrost Laboratory (GIPL) at University of Alaska Fairbanks’ ‘GIPL 1.0 – Spatially Distributed Model of Permafrost Dynamics in Alaska. The model describes permafrost distribution and active-layer thickness for the State of Alaska (at kilometer scale). Some of the data is gained from boreholes where subsurface permafrost is measured directly. More is calculated through complex equations taking into account measurements concerning soil and ground properties including temperatures, topography, vegetation, and atmospheric conditions. The data contained in the model maps current permafrost status in Alaska, and can also be leveraged to predict future permafrost status under different climate scenarios.
Romanovsky shared images of projected permafrost scenarios, the North Slope shown in hues of greys and yellows and reds. If worldwide carbon dioxide emissions continue to decline, atmospheric carbon dioxide levels could level off by roughly 2050. Only the southern edge of the North Slope map’s greys show colorful hues indicating thawing. “In this scenario we will see substantial thawing of permafrost on Alaska’s North Slope, but only in certain areas, particularly the foothills north of the Brooks Range,” Romanovsky reported. In stark contrast is a map where thawing dominates the North Slope– an eerily colorful map. If worldwide carbon dioxide emissions continue at today’s rates, North Slope permafrost thawing will be significant and extend all the way to Alaska’s north edge, the Arctic coastal plain. It is projected that after 2050 permafrost thawing would accelerate, leading to more than half of the permafrost on the North Slope thawing by 2100.
“Under these conditions, the permafrost will become unstable beneath any infrastructure such as roads, pipelines and buildings,” according to Romanovsky. “The result will be dramatic effects on infrastructure and ecosystems.” This includes infrastructure that allows for oil production and transportation on Alaska’s North Slope. And seeing as how one of the pictures he showed was the Dalton Highway (the North Slope’s lone highway) broken up by the action of permafrost and water, it’s safe to say the permafrost will become more destabilized than it already has.
Romanovsky concluded “In the North Slope of Alaska permafrost will or will not degrade by the end of the century depending on what [the] global community will be able to do about [the] increase in CO2 in the atmosphere.”
Laura Nielsen 2016
Frontier Scientists: presenting scientific discovery in the Arctic and beyond