Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Earth Science News .




ICE WORLD
The tundra a dark horse in planet Earth's greenhouse gas budget
by Staff Writers
Aarhus, Germany (SPX) Oct 16, 2013


This image shows measuring equipment in Rylekaeret fen, Zackenberg. The lawn-chair-like devices at the end of the boardwalk measure the exchange of methane and CO2 between the fen and the atmosphere. To the left is: a gradient system for measurement of the exchange of methane between the tundra and the atmosphere. Even though many of the measurements can now be made automatically, it is necessary to check the equipment regularly to ensure that everything is in good working order. Photo courtesy Laura Helene Rasmussen, Aarhus University.

Vast areas on the Northern Hemisphere are covered by tundra. Here, dwarf shrubs, sedges, mosses etc. thrive on top of permafrost in areas where only the uppermost soil layer thaws during the short Arctic summer.

New studies show that the tundra may become a source of CO2 in the future. Researcher Magnus Lund from Aarhus University explains:

"The soil below the tundra contains very large quantities of carbon - more than twice as much as is present in the planet's entire atmosphere. Therefore, we would like to know if the carbon will stay put - or if it will be released into the atmosphere as CO2 or methane as the climate warms."

Since 2000, researchers in Zackenberg in Northeast Greenland have therefore studied the carbon balance by exploring the following two figures:

1) The amount of carbon released in the form of CO2 as living organisms respire

2) The amount of carbon being stored in plants owing to photosynthesis.

Once you have established the two figures, it is possible to calculate if the tundra is a source of CO2 or if it acts as a sink absorbing carbon and storing it in living plants or in the peat layer.

"We can see that the annual release of CO2 from living organisms increases linearly as the temperature increases, measured as the average temperature in July. However, it seems that the ability of the photosynthesis to assimilate carbon stops increasing when the temperature in July rises above approx. seven degrees Celsius, which has occurred several times in past years.

"This means that the tundra may become a CO2 source if the current strong climate warming continues as expected," says Magnus Lund, before pointing out that the fear that the tundra can develop into a source of CO2 is based on a very limited number of measurements.

"It's a problem in the Arctic that we don't perform measurements at enough locations. The variation between locations is substantial both for CO2 and not least for methane. In Greenland, we measure near Nuuk and in Zackenberg, where we collect measurements from a relatively dry heath and from a moist fen area. A new station is also being established at Station Nord in the northernmost part of Greenland."

Methane remains more important
Magnus Lund emphasises that, in decades to come, from an Arctic perspective, methane will remain the primary contributor to Earth's greenhouse gas budget. In 2007, researchers from the Zackenberg research station in Northeast Greenland made a surprising discovery: In autumn, when the surface of the tundra freezes and ice is formed, large quantities of the powerful greenhouse gas methane are released. In fact, the quantities released were so large, that the annual methane emissions had to be doubled in the calculation of the tundra's methane budget.

Methane is a powerful greenhouse gas, its effect is 20-25 times as strong as that of CO2. Methane, therefore, still plays a central role for the research performed at Zackenberg.

Soil moisture crucial
Recent studies have shown that the formation of methane is closely linked to the tundra's water content - as implied by the term "swamp gas". The more water is present in the tundra, the more methane is formed. And vice versa, where there is less water, the presence of oxygen will provide the basis for formation of CO2. In this way, the soil's water content plays an important role in determining what will happen with the carbon below the tundra.

Areas that become drier will give rise to increased CO2 emissions, whereas areas that become more moist will cause the emissions of methane to increase. The water balance is affected by the temperature and precipitation, but also by the soil's content of ice.

Among other things, researchers are now working to establish how and when the methane released in autumn is formed, and if this involves new or old carbon.

Trends in CO2 exchange in a high Arctic tundra heath, 2000-2010. M. Lund et al. 2012, Journal of Geophysical Research, vol. 117, G02001, doi:10.1029/2011JG001901, 2012; Revisiting factors controlling methane emissions from high-Arctic tundra. M. Mastepanov et al. 2013, Biogeosciences, vol. 10, 5139-5158, 2013, doi:10.5194/bg-10-5139-2013

.


Related Links
Aarhus University
Zackenberg Research Station
Beyond the Ice Age






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





ICE WORLD
Russia keeps Greenpeace ship captain behind bars
Moscow (AFP) Oct 14, 2013
A Russian court on Monday rejected bail requests from the captain of a Greenpeace ship and a young female Argentinian activist involved in a protest against oil drilling in the Russian Arctic. A court in the northern region of Murmansk where the 30 crew members of the Greenpeace ship Arctic Sunrise are being held ruled that the ship's captain Pete Willcox, 60, and Camila Speziale, 21, should ... read more


ICE WORLD
Italy launches sea patrol as Sicily declares emergency

Italy deploys drones, warships after refugee tragedies

Walker's World: Is France turning racist?

India, US trying to hamper Pakistan quake relief: top militant

ICE WORLD
British engineers hope to reboot 50-year-old computer

Circadian rhythms in skin stem cells protect us against UV rays

Northwestern Researchers Develop Compact, High-Power Terahertz Source at Room Temperature

Thousands march in Romania against Canadian mine plan

ICE WORLD
Predators vs. alien: European shrimps win predatory battles with an American invader

Rising Sea Levels Threaten Everglades Freshwater Plants

Complex relationship between phosphorus and nitrogen removal in lakes

Want ripples on your icicles then add salt

ICE WORLD
The tundra a dark horse in planet Earth's greenhouse gas budget

Australia Antarctic mission focuses on penguin poo, warming

Greenpeace boss admits surprise at harsh Russian response

Russia keeps Greenpeace ship captain behind bars

ICE WORLD
Unregulated, agricultural ammonia threatens national parks' ecology

Badgers ultimately responsible for around half of TB in cattle

France's Dumex pledges change after China bribery claims

Conflict and clashes over China's prized caterpillar fungus

ICE WORLD
Hopeless search as Philippine quake death toll hits 151

Water and lava, but - curiously - no explosion

Storm Octave on Mexico Pacific coast weakens

Devotees weep as Philippines loses Church treasures

ICE WORLD
U.S. builds up military bases in Italy for African ops

Mali ex-coup leader moves out of army barracks

Islamists step up attacks in north Mali

Ethiopia says no plans to withdraw troops from Somalia

ICE WORLD
New theory of synapse formation in the brain

The Longevity of Human Civilizations

Hunters and farmers lived side-by-side for 2,000 years

Study suggests women, not men, created much of ancient cave art




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement