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UMIUJAQ, Canada鈥擮n the front line of climate change in the Canadian Arctic, scientists hunt for clues to a potentially catastrophic global warming trend: melting permafrost.
On the rolling landscape of shrubs and moss around Hudson Bay, they聽probe the once impenetrable ground now thawing in places due to global warming.
Teams are measuring the soil鈥檚 carbon content, temperature, pace of melt and the resulting release of once-trapped greenhouse gases.
鈥淭here is twice as much carbon in permafrost than in the atmosphere,鈥� said Florent Domine, a researcher with France鈥檚 National Centre for Scientific Research (CNRS).
鈥淪o if we transformed all the carbon in the permafrost into CO2, we would triple the concentration of CO2 in the atmosphere, and that would mean the end of the world as we know it.鈥�
Permafrost is perennially frozen ground covering about a quarter of exposed land in the northern hemisphere.
It contains an estimated 1.7 trillion tonnes of carbon in the form of frozen organic matter, which escapes as carbon dioxide (CO2) and methane as it warms and decomposes.
CO2 or methane?
Releasing the carbon threatens to unleash a vicious cycle in Earth鈥檚 global warming problem鈥攁dding to the greenhouse gases in the atmosphere, which in turn will spur further warming and ice melt.
鈥淧eople have called it a climate time bomb, because of the danger of a rapid release of gas from the permafrost,鈥� said Domine.
But in a brand-new field of research, the picture today is fuzzy: scientists do not know whether we risk a major release of most of the CO2 and methane, or a slow, small leak.
鈥淲e have to quantify these processes to evaluate the risk,鈥� Domine explained.
For two years, Domine and a team have been monitoring the slow transformation of the once rock-hard ground in Canada鈥檚 furthest northern to mush.
They use sensors to monitor temperature, humidity and albedo鈥攁 measure of light reflectivity which is highest in the frozen areas of the world.
The team conducts its experiments in a variety of locations, including a boreal forest and the isolated islands of Ward Hunt and Bylot off the Canadian north coast.
Climate change is warming the Arctic and sub-Arctic regions at more than double the global average, making these areas windows into the types of impacts global warming is likely to have.
A top priority is to determine what kind of gas escapes as the permafrost thaws鈥攁nd how much of it.
鈥淲ill the bacteria set free essentially be CO2? Or methane, which has an even greater warming effect?鈥� asked Domine, a snow specialist.
Carbon dioxide or CO2 is the most abundant greenhouse gas blamed for global warming, but methane is much more potent at trapping heat.
鈥楥an鈥檛 ignore it鈥�
Impacts of the thaw are already visible.
Millions of ponds of different sizes have formed, scattered over the Arctic region, as the receding permafrost聽collapses unevenly in on itself.
Any hollows quickly fill with melted ice and rainwater.
鈥淎bout 10 to 100 times more CO2 escapes from the ponds than from the soil,鈥� said Maria Belke-Bria, a doctoral student on Domine鈥檚 team.
The moisture speeds up decomposition of the now-exposed organic material.
But at the same time, the melt has created small valleys in the once barren ground, where spruces and dwarf birch trees now flourish. Plants absorb carbon dioxide.
鈥淲e want to know if this new vegetation鈥� protects the permafrost or is hastening its melt,鈥� said Belke-Bria.
Scientists do not yet know whether the net effect will be one of cooling or warming.
In fact, the entire field of study remains shrouded in uncertainty, and permafrost鈥檚 potential contribution to planet warming is not included in future projections of climate change.
The UN鈥檚 climate science panel also did not quantify the risk from permafrost thaw in its latest, seminal global warming report.
Part of the problem is that this is such a challenging and expensive phenomenon to study鈥攏ot least because the region is remote and hard to reach, and the pockets of research funders empty.
But Domine insisted: 鈥渨e cannot ignore this question.鈥�
What is clear is that there will be no 鈥渓ocal鈥� solution to the problem, he stressed.
鈥淲e cannot capture carbon escaping over a surface of 10 million square kilometers,鈥� stated the researcher.
鈥淪topping global warming is the only answer.鈥�
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