Global warming in the Canadian Arctic

Nov 18, 2013

Ph.D. student Karita Negandhi and professor Isabelle Laurion from INRS'Eau Terre Environnement Research Centre, in collaboration with other Canadian, U.S., and French researchers, have been studying methane emissions produced by thawing permafrost in the Canadian Arctic. These emissions are greatly underestimated in current climate models. Their findings, published in the journal PLOS ONE, illustrate the importance of taking into account greenhouse gases emitted by small thaw ponds, as they could have a significant impact on climate.

"We discovered that although the small shallow ponds we studied represent only 44% of the water-covered surface in a Bylot Island valley, they generate 83% of its ," notes water sciences doctoral student Karita Negandhi.

The researchers compared ponds of different shapes and sizes, and studied their physicochemical properties and microbial ecology. To analyze the samples taken on Bylot Island in Nunavut's Sirmilik National Park, they used various methods, including radiocarbon dating, as well as new-generation molecular tools to study the sediment and water microbial communities involved in carbon transformation processes.

The isotopic signatures of the methane emitted by these small ponds indicate that this comes partly from old carbon reserves that have been sequestered in the for millennia. As the permafrost thaws, organic matter is becoming more abundant, promoting the proliferation of aquatic microbes such as methanogenic Archaea, which use various sources of carbon, then release it into the atmosphere in the form of methane and CO2. Consequently, longer summers could lead to an increase in these emissions.

These small thaw ponds have been studied very little up until now, primarily because of their remote location and the attendant logistical constraints. However in the context of global warming, they are worth examining more closely, as they could have an increasingly significant incidence on the transfer of into the atmosphere in the future.

Explore further: The tundra—a dark horse in planet Earth's greenhouse gas budget

More information: The article entitled "Small thaw ponds: an unaccounted source of methane in the Canadian High Arctic" appeared in PLOS ONE on November 13, 2013.

add to favorites email to friend print save as pdf

Related Stories

New knowledge about permafrost improving climate models

Jul 28, 2013

New research findings from the Centre for Permafrost (CENPERM) at the Department of Geosciences and Natural Resource Management, University of Copenhagen, document that permafrost during thawing may result in a substantial ...

Abrupt permafrost thaw increases climate threat

Nov 30, 2011

As the Arctic warms, greenhouse gases will be released from thawing permafrost faster and at significantly higher levels than previous estimates, according to survey results from 41 international scientists ...

Recommended for you

Landmark fracking study finds no water pollution

1 hour ago

The final report from a landmark federal study on hydraulic fracturing, or fracking, has found no evidence that chemicals or brine water from the gas drilling process moved upward to contaminate drinking water at one site ...

Politics divide coastal residents' views of environment

2 hours ago

From the salmon-rich waters of Southeast Alaska to the white sand beaches of Florida's Gulf Coast to Downeast Maine's lobster, lumber and tourist towns, coastal residents around the U.S. share a common characteristic: ...

Earthworms as nature's free fertilizer

6 hours ago

Earthworm presence in the soil increases crop yield, shows a new study that was published this week in Scientific Reports. "This is not unexpected," says Jan Willem van Groenigen, associate professor in the ...

A success in managed pressure drilling

6 hours ago

As one of BP's top 40 wells globally (and the only UK well qualifying for that category in 2012), the successful delivery of the Harding field's 'Producer North East 2a' well (referred to as PNE2a) was crucial to the business. ...

Passion for the natural world clears the waters

6 hours ago

A toxic legacy has hung over the picturesque northern NSW coastal hamlet of Urunga for almost 40 years. Although now obscured by dense vegetation, the forest of dead melaleuca trees at the edge of a wetland ...

User comments : 0