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: Sediment trapped behind dams makes them 'hot spots' for greenhouse gas emissions

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

US delays decision on Keystone pipeline project

Apr 18, 2014

The United States announced Friday a fresh delay on a final decision regarding a controversial Canada to US oil pipeline, saying more time was needed to carry out a review.

New research on Earth's carbon budget

Apr 18, 2014

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

User comments : 0

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...