New research will allow more reliable dating of major past events

Academics have developed a new method which will allow key past events to be dated more accurately.

Research led by Professors Paul Blackwell and Caitlin Buck from the University of Sheffield’s School of Mathematics and Statistics and Professor Paula Reimer from Queen’s University Belfast has resulted in a new, internationally agreed radiocarbon calibration curve which will provide improved accuracy to archaeologists, environmental scientists and climate researchers who rely on radiocarbon dating to put their findings onto a reliable time-scale.

The release of the new curve will mean that more precise date estimates can be obtained than previously possible and will reduce uncertainty about the timing of major events in the history and development of humans, plants and animals and the environments in which they lived.

The radiocarbon calibration curve would allow researchers to reliably date everything from items like the recently excavated bones of King Richard III, to confirm they were from the right time period, to baby woolly mammoths preserved in permafrost in Siberia. It also provides reliable time-scales for those seeking to understand ancient environments, including members of the International Panel on Climate Change.

Professor Caitlin Buck, from the University of Sheffield, said: “We are proud to have developed such an important tool for archaeologists and environmental scientists, allowing them to more accurately date their findings and reduce uncertainty about the timings of major events. We’re also grateful to the more than 30 other scientists who have shared data and research ideas with us to make it all possible.”

Professor Paula Reimer, from Queen’s University Belfast added: “This project built on research begun in the 1980s at Queen’s and elsewhere and is essential for the continued utility and development of radiocarbon dating.”

Drilling for hydrocarbons can impact aquatic life

This large drilling sump exhibits ponding both on the surface and perimeter. -  Joshua Thienpont
This large drilling sump exhibits ponding both on the surface and perimeter. – Joshua Thienpont

The degradation of drilling sumps associated with hydrocarbon extraction can negatively affect aquatic ecosystems, according to new research published November 6th in the open-access journal PLOS ONE by Joshua Thienpont and colleagues at Queen’s University and other institutions.

Hydrocarbons are a primary source of energy as combustible fuel. Although hydrocarbon exploration and extraction are profitable enterprises, hydrocarbons contribute to the formation of greenhouse gases and are therefore a major stressor to the environment.

During the process of exploring for hydrocarbons, drilling sumps are used to permanently store the waste associated with drilling. In the Mackenzie Delta region of Canada’s western Arctic, more than 150 drilling sumps were constructed for this purpose. Although the areas surrounding the sumps were believed to be frozen by the surrounding permafrost, recent findings suggest that these areas may actually be thawing. In this study, the authors examine the environmental effects of this type of drilling sump containment loss in the Mackenzie Delta.

Because drilling fluids are saline, they tested whether leakage to surface waters was occurring by measuring changes in conductivity, as saline is more conductive than pure water. They also hypothesized that if saline-rich wastes from drilling sumps were impacting lakes, there should be changes in the types of life forms present. Zooplankton, for example, are a key component of aquatic ecosystems and various species survive differently in saline versus fresh water.

Through an analysis of lake sediments, they found changes in the community composition of zooplankton due to sump degradation. These results suggest that climate change and permafrost thaw can have deleterious consequences to aquatic life through the degradation and leaking of drilling sumps.

Thienpont elaborates, “The leaching of wastes from drilling sumps represents a newly identified example of one of the cumulative impacts of recent climate change impacting the sensitive freshwater ecosystems of the Arctic.”

Cracking the ice code

UWM geosciences professor John Isbell (left) and postdoctoral researcher Erik Gulbranson, University of Wisconsin, Milwaukee, look over some of the many samples they have brought back from Antarctica. The two are part of an international team of scientists investigating the last extreme climate shift on Earth, which occurred in the late Paleozoic Era. -  Troye Fox
UWM geosciences professor John Isbell (left) and postdoctoral researcher Erik Gulbranson, University of Wisconsin, Milwaukee, look over some of the many samples they have brought back from Antarctica. The two are part of an international team of scientists investigating the last extreme climate shift on Earth, which occurred in the late Paleozoic Era. – Troye Fox

What happened the last time a vegetated Earth shifted from an extremely cold climate to desert-like conditions? And what does it tell us about climate change today?

John Isbell is on a quest to coax that information from the geology of the southernmost portions of the Earth. It won’t be easy, because the last transition from “icehouse to greenhouse” occurred between 335 and 290 million years ago.

An expert in glaciation from the late Paleozoic Era, Isbell is challenging many assumptions about the way drastic climate change naturally unfolds. The research helps form the all-important baseline needed to predict what the added effects of human activity will bring.

Starting from ‘deep freeze’

In the late Paleozoic, the modern continents were fused together into two huge land masses, with what is now the Southern Hemisphere, including Antarctica, called Gondwana.

During the span of more than 60 million years, Gondwana shifted from a state of deep freeze into one so hot and dry it supported the appearance of reptiles. The change, however, didn’t happen uniformly, Isbell says.

In fact, his research has shaken the common belief that Gondwana was covered by one massive sheet of ice which gradually and steadily melted away as conditions warmed.

Isbell has found that at least 22 individual ice sheets were located in various places over the region. And the state of glaciation during the long warming period was marked by dramatic swings in temperature and atmospheric carbon dioxide (CO2) levels.

“There appears to be a direct association between low CO2 levels and glaciation,” he says. “A lot of the changes in greenhouse gases and in a shrinking ice volume then are similar to what we’re seeing today.”

When the ice finally started disappearing, he says, it did so in the polar regions first and lingered in other parts of Gondwana with higher elevations. He attributes that to different conditions across Gondwana, such as mountain-building events, which would have preserved glaciers longer.

All about the carbon

To get an accurate picture of the range of conditions in the late Paleozoic, Isbell has traveled to Antarctica 16 times and has joined colleagues from around the world as part of an interdisciplinary team funded by the National Science Foundation. They have regularly gone to places where no one has ever walked on the rocks before.

One of his colleagues is paleoecologist Erik Gulbranson, who studies plant communities from the tail end of the Paleozoic and how they evolved in concert with the climatic changes. The information contained in fossil soil and plants, he says, can reveal a lot about carbon cycling, which is so central for applying the work to climate change today.

Documenting the particulars of how the carbon cycle behaved so long ago will allow them to answer questions like, ‘What was the main force behind glaciation during the late Paleozoic? Was it mountain-building or climate change?’

Another characteristic of the late Paleozoic shift is that once the climate warmed significantly and atmospheric CO2 levels soared, the Earth’s climate remained hot and dry for another 200 million years.

“These natural cycles are very long, and that’s an important difference with what we’re seeing with the contemporary global climate change,” says Gulbranson. “Today, we’re seeing change in greenhouse gas concentrations of CO2 on the order of centuries and decades.”

Ancient trees and soil

In order to explain today’s accelerated warming, Gulbranson’s research illustrates that glaciers alone don’t tell the whole story.

Many environmental factors leave an imprint on the carbon contained in tree trunks from this period. One of the things Gulbranson hypothesizes from his research in Antarctica is that an increase in deciduous trees occurred in higher latitudes during the late Paleozoic, driven by higher temperatures.

What he doesn’t yet know is what the net effect was on the carbon cycle.

While trees soak in CO2 and give off oxygen, there are other environmental processes to consider, says Gulbranson. For example, CO2 emissions also come from soil as microbes speed up their consumption of organic matter with rising temperatures.

“The high latitudes today contain the largest amount of carbon locked up as organic material and permafrost soils on Earth today,” he says. “It actually exceeds the amount of carbon you can measure in the rain forests. So what happens to that stockpile of carbon when you warm it and grow a forest over it is completely unknown.”

Another unknown is whether the Northern Hemisphere during this time was also glaciated and warming. The pair are about to find out. With UWM backing, they will do field work in northeastern Russia this summer to study glacial deposits from the late Paleozoic.

The two scientists’ work is complementary. Dating the rock is essential to pinpointing the rate of change in the carbon cycle, which would be the warning signal we could use today to indicate that nature is becoming dangerously unbalanced.

“If we figure out what happened with the glaciers,” says Isbell, “and add it to what we know about other conditions – we will be able to unlock the answers to climate change.”

Thawing permafrost may have led to extreme global warming events

Scientists analyzing prehistoric global warming say thawing permafrost released massive amounts of carbon stored in frozen soil of Polar Regions exacerbating climate change through increasing global temperatures and ocean acidification.

Although the amounts of carbon involved in the ancient soil-thaw scenarios was likely much greater than today, the implications of this ground-breaking study are that the long-term future of carbon deposits locked into frozen permafrost of Polar Regions are vulnerable to climate warming caused as humans emit the greenhouse gas carbon dioxide by burning fossil fuels for energy generation.

Researchers in centres across America, Italy and the University of Sheffield, analysed a series of sudden, and extreme, global warming events – called hyperthermals – that occurred about 55 million years ago, linked to rising greenhouse gas concentrations and changes in Earth’s orbit, which led to a massive release of carbon into the atmosphere, ocean acidification, and a five degrees Celsius rise in global temperature within just a few thousand years.

It was previously thought that the source of carbon was in the ocean, in the form of frozen methane gas in ocean-floor sediments but now the experts believe the carbon released into the atmosphere millions of years ago came from the Polar Regions.

Professor David Beerling, of the University of Sheffield’s Department of Animal and Plant Sciences, said: “For the first time, we have linked these past global warming events with a climatically sensitive terrestrial carbon reservoir rather than a marine one. It shows that global warming can be amplified by carbon release from thawing permafrost.”

“The research suggests that carbon stored in permafrost stocks today in the Arctic region is vulnerable to warming. Warming causes permafrost thaw and decomposition of organic matter releasing more greenhouse gases back into the atmosphere.

“This feedback loop could accelerate future warming. It means we must arrest carbon dioxide emissions released by the combustion of fossil fuels if humanity wishes to avoid triggering these sorts of feedbacks in our modern world.”

The breakthrough was made through cross-disciplinary collaborations with climate and vegetation modellers, isotope geochemists and permafrost experts led by Rob DeConto at the University of Massachusetts, in collaboration with the University of Sheffield, Yale, the University of Colorado, Penn State, and the University of Urbino, Italy.

Rob DeConto added: “Similar dynamics are at play today. Global warming is degrading permafrost in the north Polar Regions, unlocking once-frozen carbon and methane and releasing it into the atmosphere. This will only exacerbate future warming in a positive feedback loop.”

The temperature of Earth’s atmosphere is a result of energy input from the sun minus what escapes back into space. Carbon dioxide in the atmosphere absorbs and traps heat that would otherwise return to space.

The global warming events were accompanied by a massive input of carbon to the atmosphere plus ocean acidification, and were characterized by a global temperature rise of about five degrees Celsius within a few thousand years.

Until now, scientists have been unable to account for the massive amounts of carbon required to cause such dramatic global warming events and Antarctica, which on today’s Earth is covered by kilometres of ice, has not been appreciated as an important player in such global carbon dynamics.

The research is published in the journal Nature.

Signs of thawing permafrost revealed from space

Permafrost is ground that remains at or below 0°C for at least two consecutive years and usually appears in areas at high latitudes such as Alaska, Siberia and Northern Scandinavia, or at high altitudes like the Andes, Himalayas and the Alps. About half of the world’s underground organic carbon is found in northern permafrost regions. This is more than double the amount of carbon in the atmosphere in the form of the greenhouse gases carbon dioxide and methane.

The effects of climate change are most severe and rapid in the Arctic, causing the permafrost to thaw. When it does, it releases greenhouse gases into the atmosphere, exacerbating the effects of climate change.

Although permafrost cannot be directly measured from space, factors such as surface temperature, land cover and snow parameters, soil moisture and terrain changes can be captured by satellites.

The use of satellite data like from ESA’s Envisat, along with other Earth-observing satellites and intensive field measurements, allows the permafrost research community to get a panoptic view of permafrost phenomena from a local to a Circum-Arctic dimension.

“Combining field measurements with remote sensing and climate models can advance our understanding of the complex processes in the permafrost region and improve projections of the future climate,” said Dr Hans-Wolfgang Hubberten, head of the Alfred Wegner Institute Research Unit (Germany) and President of the International Permafrost Association.

Last month, more than 60 permafrost scientists and Earth observation specialists came together for the Third Permafrost User Workshop at the Alfred Wegener Institute in Potsdam, Germany, to discuss their latest findings.

“The already available Permafrost products provide researchers with valuable datasets which can be used in addition to other observational data for climate and hydrological modelling,” said Dr Leonid Bobylev, the director of the Nansen Centre in St. Petersburg.

“However, for climate change studies – and in particular for evaluation of the climate models’ performance – it is essential to get a longer time series of satellite observational data.

“Therefore, the Permafrost related measurements should be continued in the future and extended consistently in the past.”

ESA will continue to monitor the permafrost region with its Envisat satellite and the upcoming Sentinel satellite series for Europe’s Global Monitoring for Environment and Security (GMES) programme.

Thawing permafrost likely will accelerate global warming

Up to two-thirds of Earth's permafrost likely will disappear by 2200 as a result of warming temperatures, unleashing vast quantities of carbon into the atmosphere, says a new study by the University of Colorado Boulder's Cooperative Institute for Research in Environmental Sciences. -  University of Colorado
Up to two-thirds of Earth’s permafrost likely will disappear by 2200 as a result of warming temperatures, unleashing vast quantities of carbon into the atmosphere, says a new study by the University of Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences. – University of Colorado

Up to two-thirds of Earth’s permafrost likely will disappear by 2200 as a result of warming temperatures, unleashing vast quantities of carbon into the atmosphere, says a new study by the University of Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences.

The carbon resides in permanently frozen ground that is beginning to thaw in high latitudes from warming temperatures, which will impact not only the climate but also international strategies to reduce fossil fuel emissions, said CU-Boulder’s Kevin Schaefer, lead study author. “If we want to hit a target carbon dioxide concentration, then we have to reduce fossil fuel emissions that much lower than previously thought to account for this additional carbon from the permafrost,” he said. “Otherwise we will end up with a warmer Earth than we want.”

The escaping carbon comes from plant material, primarily roots trapped and frozen in soil during the last glacial period that ended roughly 12,000 years ago, he said. Schaefer, a research associate at CU-Boulder’s National Snow and Ice Data Center, an arm of CIRES, likened the mechanism to storing broccoli in a home freezer. “As long as it stays frozen, it stays stable for many years,” he said. “But if you take it out of the freezer it will thaw out and decay.”

While other studies have shown carbon has begun to leak out of permafrost in Alaska and Siberia, the study by Schaefer and his colleagues is the first to make actual estimates of future carbon release from permafrost. “This gives us a starting point, and something more solid to work from in future studies,” he said. “We now have some estimated numbers and dates to work with.”

The new study was published online Feb. 14 in the scientific journal Tellus. Co-authors include CIRES Fellow and Senior Research Scientist Tingjun Zhang from NSIDC, Lori Bruhwiler of the National Oceanic and Atmospheric Administration and Andrew Barrett from NSIDC. Funding for the project came from NASA, NOAA and the National Science Foundation.

Schaefer and his team ran multiple Arctic simulations assuming different rates of temperature increases to forecast how much carbon may be released globally from permafrost in the next two centuries. They estimate a release of roughly 190 billion tons of carbon, most of it in the next 100 years. The team used Intergovernmental Panel on Climate Change scenarios and land-surface models for the study.

“The amount we expect to be released by permafrost is equivalent to half of the amount of carbon released since the dawn of the Industrial Age,” said Schaefer. The amount of carbon predicted for release between now and 2200 is about one-fifth of the total amount of carbon in the atmosphere today, according to the study.

While there were about 280 parts per million of CO2 in Earth’s atmosphere prior to the Industrial Age beginning about 1820, there are more than 380 parts per million of carbon now in the atmosphere and the figure is rising. The increase, equivalent to about 435 billion tons of carbon, resulted primarily from human activities like the burning of fossil fuels and deforestation.

Using data from all climate simulations, the team estimated that about 30 to 60 percent of Earth’s permafrost will disappear by 2200. The study took into account all of the permanently frozen ground at high latitudes around the globe.

The consensus of the vast majority of climate scientists is that the buildup of CO2 and other greenhouse gases in Earth’s atmosphere is the primary reason for increasingly warm temperatures on Earth. According to NOAA, 2010 was tied for the hottest year on record. The hottest decade on record occurred from 2000 to 2010.

Greater reductions in fossil fuel emissions to account for carbon released by the permafrost will be a daunting global challenge, Schaefer said. “The problem is getting more and more difficult all the time,” he said. “It is hard enough to reduce the emissions in any case, but now we have to reduce emissions even more. We think it is important to get that message out now.”

Scientist joins global study of decomposing permafrost

The Lapland gate connects one side of Lapland to another; as seen from Abisco, Sweden, north of the Arctic Circle. -  Courtesy Jeff Chanton, FSU Department of Earth, Ocean and Atmospheric Science
The Lapland gate connects one side of Lapland to another; as seen from Abisco, Sweden, north of the Arctic Circle. – Courtesy Jeff Chanton, FSU Department of Earth, Ocean and Atmospheric Science

Florida State University oceanographer Jeff Chanton is part of an international team embarking on a new study of permafrost decomposition in arctic Sweden. What he and his fellow researchers discover there may be critical given the permafrost’s key role in climate change, and vice versa.

It is all part of an ominous feedback loop, Chanton says.

The warming climate is causing the Swedish permafrost to thaw and decompose and, as it does, the greenhouse gases carbon dioxide and methane are released into the atmosphere, creating a feedback loop of further warming temperatures and accelerating permafrost’s decomposition.

“There are 1,672 gigatons of carbon stored in the permafrost as soil and peat organic matter,” Chanton said. “To put that quantity in perspective, it is three times the amount of carbon found in our atmosphere, which contains 550 gigatons in the form of carbon dioxide. What will happen if all the permafrost thaws, releasing its gigantic store of carbon into the atmosphere? Will the respiration of that decomposing organic matter by bacteria produce not only carbon dioxide but also methane, a greenhouse gas 25 times more potent?

“We know that increasing carbon dioxide and methane in the atmosphere creates a positive feedback to global warming,” he said. “Our new study will shed vital additional light on how the thawing affects the atmosphere, which affects warming, and how the thawing of the permafrost affects the organic carbon stored there.”

A three-year, $2.8 million grant from the U.S. Department of Energy will fund the collaborative investigation, to be undertaken by researchers from five universities on three continents. University of Arizona scientists are leading the team, which includes Florida State’s Chanton and research colleagues at the universities of New Hampshire, Stockholm (Sweden), and Queensland (Australia).

Chanton will receive a $300,000 share of the DOE grant. He also has a part of a larger share of the award that will be used to purchase lasers and other field instruments for the entire team.

The study will periodically find Chanton north of the Arctic Circle, where he kicked off his research in August near Abisco, Sweden, amid the mosquitoes and black flies typical of the arctic summer there. While this is his first foray into Sweden’s remote arctic realms, Chanton is no stranger to permafrost research. His previous studies focused on Alaska and Siberia.

Study finds permafrost warming, monitoring improving

University of Alaska Fairbanks Professor Vladimir Romanovsky measures permafrost temperature at a borehole in interior Alaska. -  Photo by A. Kholodov.
University of Alaska Fairbanks Professor Vladimir Romanovsky measures permafrost temperature at a borehole in interior Alaska. – Photo by A. Kholodov.

Permafrost warming continues throughout a wide swath of the Northern Hemisphere, according to a team of scientists assembled during the recent International Polar Year.

Their extensive findings, published in the April-June 2010 edition of Permafrost and Periglacial Processes, describe the thermal state of high-latitude permafrost during the International Polar Year, 2007-2009. Vladimir Romanovsky, a professor with the snow, ice and permafrost group at the University of Alaska Fairbanks Geophysical Institute, is the lead author of the paper, which also details the significant expansion of Northern Hemisphere permafrost monitoring.

“This paper is actually pretty unique,” Romanovsky said, “because it’s the first time such a large geographical area has been involved in one paper.”

During the International Polar Year, Romanovsky and his colleagues launched a field campaign to improve the existing permafrost-monitoring network. The permafrost thermal state is monitored with borehole sensors, which gather data from holes drilled deep into the permafrost. The researchers established nearly 300 borehole sites that serve as permafrost observatories across the polar and sub-polar regions in the Northern Hemisphere. Their work more than doubled the size of the previously existing network

“The heart of monitoring is the measuring of temperatures in boreholes,” Romanovsky said. “For permafrost temperatures, you have to be there. You have to establish boreholes.”

Having data from across the circumpolar North allows scientists to analyze trends affecting permafrost. The article notes that permafrost temperatures have warmed as much as two degrees Celsius from 20 to 30 years ago. They also found that permafrost near zero degrees Celsius warmed more slowly than colder permafrost. According to Romanovsky, this trend is an example of the large-scale analysis possible using data from the expanded network.

The enlarged and revamped observatory network is meant to be a building block for further research. It also has the potential to foster better modeling of future conditions and act as an early warning system of the negative consequences of climate change in permafrost regions. That could, in turn, help policymakers and the public plan for a future with warmer permafrost.

Romanovsky, whose specialty is Russian and North American permafrost conditions, plans to keep building on the legacy of the International Polar Year. With help from a five-year National Science Foundation grant, he continues his collaboration with American and international colleagues, establishing new borehole sites in undersampled areas and analyzing trends evidenced by the newly available data.

The Fourth International Polar Year was a two-year event that began in March of 2007 and focused the attention of the international research community on the Earth’s polar regions. UAF researchers were heavily involved in IPY projects and are still analyzing data from those projects.

Stream water study detects thawing permafrost

The Storflaket  permafrost plateau bog near Abisko in northern Sweden  shows cracks at its borders due to thawing of the permafrost.
The Storflaket permafrost plateau bog near Abisko in northern Sweden shows cracks at its borders due to thawing of the permafrost.

Among the worrisome environmental effects of global warming is the thawing of Arctic permafrost—soil that normally remains at or below the freezing point for at least a two-year period and often much longer. Monitoring changes in permafrost is difficult with current methods, but a study by University of Michigan researchers offers a new approach to assessing the extent of the problem.

The new study approach, which relies on chemical tracers in stream water, is described in the journal Chemical Geology.

Overlying permafrost is a thin “active layer” that thaws every summer, and increases in the thickness of this layer over the years indicate thawing of permafrost. Both physical measurements and modeling suggest that active layer thickness has increased in some areas over the 20th century and that if present warming trends continue, increases of up to 40 percent could occur by the end of the 21st century.

Although the full effects of thawing are yet to be determined, coastal erosion and damage to the roads, buildings and pipelines that have been built on permafrost are likely outcomes. In addition, thawing permafrost may release the greenhouse gases carbon dioxide and methane into the atmosphere, triggering further warming and more permafrost thawing.

Currently, the main method for determining thaw depth is with a graduated steel probe. “You stick it in the ground and see when it hits frozen material,” said geochemist Joel Blum, who with ecologist George Kling and former graduate student Katy Keller undertook the new study.

“We were studying the chemistry of soils in the area around Toolik Field Station in northern Alaska, and we found that once we got below the thickness that typically would thaw during summer, the soil chemistry changed dramatically,” said Blum, who is the John D. MacArthur Professor of Geological Sciences. “Material that has not thawed since it was deposited by glaciers 10,000 to 20,000 years ago is now beginning to thaw, and when it does, it reacts strongly with water, which it’s encountering for the first time. This soil is much more reactive than soils higher up that interact with soil water every summer.”

In particular, the amount of calcium, relative to sodium and barium, is higher in the newly-thawed permafrost, and the ratio of the strontium isotope 87Sr to its counterpart 86Sr is lower. The researchers wondered if these chemical signatures of increasing thaw depth could be seen in local stream water.

Kling, who is the Robert G. Wetzel Collegiate Professor of Ecology and Evolutionary Biology, has conducted research at Toolik Lake for many years and obtained stream water samples that had been collected over an 11-year period.

When the samples were analyzed, “we saw really significant changes from year to year that were consistent with what you would predict from increasing thaw depth,” Kling said.

Although the method can’t reveal precisely how much permafrost thawing is occurring in particular localities, it still can be a useful adjunct to current methods, Blum said. “We’d love to be able to say that we see an increase in thickness of, say, 1 centimeter over the entire watershed, but we simply can’t say where in the watershed thawing is occurring. Nevertheless, we think it’s important to monitor streams in Arctic regions to keep track of these kinds of changes and follow the rate of change.”

Permafrost line recedes 130 km in 50 years

Pictured are lichen and shrub-covered palsas surrounded by a pond resulting from melting permafrost in a bog near the village of Radisson, Canada. -  Serge Payette
Pictured are lichen and shrub-covered palsas surrounded by a pond resulting from melting permafrost in a bog near the village of Radisson, Canada. – Serge Payette

The southern limit of permanently frozen ground, or permafrost, is now 130 kilometers further north than it was 50 years ago in the James Bay region, according to two researchers from the Department of Biology at Université Laval. In a recent issue of the scientific journal Permafrost and Periglacial Processes, Serge Payette and Simon Thibault suggest that, if the trend continues, permafrost in the region will completely disappear in the near future.

The researchers measured the retreat of the permafrost border by observing hummocks known as “palsas,” which form naturally over ice contained in the soil of northern peat bogs. Conditions in these mounds are conducive to the development of distinct vegetation-lichen, shrubs, and black spruce-that make them easy to spot in the field.

In an initial survey in 2004, the researchers examined seven bogs located between the 51st and 53rd parallels. They noted at that time that only two of the bogs contained palsas, whereas aerial photos taken in 1957 showed palsas present in all of the bogs. A second assessment in 2005 revealed that the number of palsas present in these two bogs had decreased over the course of one year by 86% and 90% respectively.

Helicopter flyovers between the 51st and 55th parallels also revealed that the palsas are in an advanced state of deterioration over the entire James Bay area.

While climate change is the most probable explanation for this phenomenon, the lack of long term climatic data for the area makes it impossible for the researchers to officially confirm this. Professor Payette notes, however, that the average annual temperature of the northern sites he has studied for over 20 years has increased by 2 degrees Celsius. “If this trend keeps up, what is left of the palsas in the James Bay bogs will disappear altogether in the near future, and it is likely that the permafrost will suffer the same fate,” concludes the researcher affiliated to the Centre d’études nordiques.