Environment
Study of wolves will help scientists predict climate effects on endangered animals — Scientists studying populations of grey wolves in the USA's Yellowstone National Park have developed a way to predict how changes in the environment will impact on the animals' number,…
Climate sensitivity to CO2 more limited than extreme projections — A new study suggests that the rate of global warming from doubling of atmospheric carbon dioxide may be less than the most dire estimates of some previous studies - and, in fact, may…
Saving Da Vinci's Last Supper from air pollution — Having survived long centuries, political upheaval, and even bombings during World War II, Leonardo Da Vinci's masterpiece Last Supper now faces the risk of damage from air pollution…
After 25 years, sustainability is a growing science that's here to stay — Sustainability has not only become a science in the past 25 years, but it is one that continues to be fast-growing with widespread international collaboration, broad disciplinary composition…
Markets drive conservation in Central Africa — Certification has shown that commercial forestry can co-exist with conservation objectives in the Congo Basin, according to conclusions reached at an international seminar 'Forest management…
Great Plains river basins threatened by pumping of aquifers — Suitable habitat for native fishes in many Great Plains streams has been significantly reduced by the pumping of groundwater from the High Plains aquifer - and scientists analysing…
Rivers may aid climate control in cities — Speaking at the URSULA (Urban River Corridors and Sustainable Living Agendas) Conference, in Sheffield, Dr Abigail Hathway, of the University of Sheffield, will demonstrate how rivers…
Vultures dying at alarming rate — Vultures in South Asia were on the brink of extinction until Lindsay Oaks and Richard Watson, from The Peregrine Fund in the US, undertook observational and forensic studies to find…
Predicting future threats for global amphibian biodiversity — Amphibian populations are declining worldwide, and their declines far exceed those of other animal groups: more than 30% of all species are listed as threatened according to the Red…
Study shows deforestation causes cooling — Deforestation, considered by scientists to contribute significantly to global warming, has been shown by a Yale-led team to actually cool the local climate in northern latitudes, according…
Where am I? > Home > News > Environment

Scientist links increase in greenhouse gases to changes in ocean currents

Science Centric | 18 June 2010 15:01 GMT
Printable version A clip for your blog or website E-mail the story to a friend
Bookmark or share the story on your social network Vote for this article Decrease text size Increase text size
DON'T MISS —
'Fuel for thought' on transport sector challenges
'Fuel for thought' on transport sector challenges — A report on how Australia can best respond to the environmental and economic challenges arising from its dependence on fossil…
Conservationist to aid parrots in peril
Conservationist to aid parrots in peril — A once critically endangered species of parrot now under threat from a highly contagious virus may be offered a renewed chance…
More Environment

By examining 800,000-year-old polar ice, scientists increasingly are learning how the climate has changed since the last ice melt and that carbon dioxide has become more abundant in the Earth's atmosphere.

For two decades, French scientist Jerome Chappellaz has been examining ice cores collected from deep inside the polar ice caps of Greenland and Antarctica. His studies on the interconnecting air spaces of old snow - or firn air - in the ice cores show that the roughly 40 percent increase of carbon dioxide in the atmosphere since the Earth's last deglaciation can be attributed in large part to changes in the circulation and biological activity of the oceanic waters surrounding Antarctica.

Chappellaz presented his findings today in Knoxville, Tenn. during the Goldschmidt Conference, an international gathering of several thousand geochemists who converge annually to share their research on Earth, energy and the environment. The event, hosted by the University of Tennessee, Knoxville, and Oak Ridge National Laboratory, is taking place June 13-18.

By measuring the carbon isotopes in the firn air, scientists can pinpoint the source of atmospheric carbon during the millennia. Because living organisms at the surface of the oceans tend to take up the lighter of the carbon isotopes, 13C, and this isotope is then released when the organisms decay, scientists know the higher concentration of 13C is originating from the oceans.

Normally, the organisms die, sink to the ocean depths, and decompose, releasing carbon that remains stored in the cold, deep waters for centuries. But a growing concentration of the isotope 13C in the air during the last deglaciation indicates that this 'old' carbon from decomposition was released from the southern polar waters, where the Antarctic Circumpolar Current transports more water than any other current in the world. Here, oceanic circulation is increasing in intensity and the deep water is releasing carbon dioxide at the surface.

For two decades, Chappellaz has examined polar ice cores to decipher how the primary greenhouse gases - carbon dioxide, methane and nitrous oxide - have changed in concentrations and ratios since ancient times and what has caused those changes. He notably showed for the first time the tight link existing between atmospheric methane and global climate at glacial-interglacial time scales. Chappellaz is research director at the Laboratoire de Glaciologie et Geophysique de Environnement in Grenoble, France.

Source: University of Tennessee at Knoxville


Leave a comment
The details you provide on this page [e-mail address] will not be used to send unsolicited e-mail, and will not be supplied to a third party! Please note that we can not promise to give everyone a response. Comments are fully moderated. Once approved they will be posted within 24 hours.
Expand the form to leave a comment

RSS FEEDS, NEWSLETTER
Find the topic you want. Science Centric offers several RSS feeds for the News section.

Or subscribe for our Newsletter, a free e-mail publication. It is published practically every day.

Project seeks clues to climate change in remote atmospheric regionProject seeks clues to climate change in remote atmospheric region

— Scientists are deploying an advanced research aircraft to study a region of the atmosphere that influences climate change by affecting the amount of solar heat that…

Creating a safe zone for endangered right whalesCreating a safe zone for endangered right whales

— It's called the 'area to be avoided,' - 1,000 square nautical miles located in the Roseway Basin region of the Scotian Shelf, just south of Barrington, N.S. And…

Joint NASA-French satellite to track trends in sea level, climateJoint NASA-French satellite to track trends in sea level, climate

— A satellite that will help scientists better monitor and understand rises in global sea level, study the world's ocean circulation and its links to Earth's climate,…

New research examines the excessive reactive nitrogen entering the environmentNew research examines the excessive reactive nitrogen entering the environment

— While human-caused global climate change has long been a concern for environmental scientists and is a well-known public policy issue, the problem of excessive reactive…

Popular tags in Environment: climate · ecosystem · nitrogen · pollution