Featured Research

from universities, journals, and other organizations

Oxygen Measurements Yield Greenhouse Clues

Date:
July 19, 1999
Source:
CSIRO Australia
Summary:
CSIRO scientists have measured a very small decline in oxygen in our atmosphere over the past 20 years.

As levels of the greenhouse gas carbon dioxide rise, concentrations of oxygen in our air have fallen.

CSIRO scientists have measured the minuscule decline in oxygen that has occurred during the past 20 years, the longest period over which such an assessment has been made.

"As fossil fuels burn, they generate carbon dioxide, using up oxygen in the process," explains Mr Ray Langenfelds from CSIRO Atmospheric Research. "About half of the carbon dioxide from fossil fuels remains in the atmosphere."

"The changes we are measuring represent just a tiny fraction of the total amount of oxygen in our air (20.95 per cent by volume). The oxygen reduction is just 0.03 per cent in the past 20 years and has no impact on our breathing," says Mr Langenfelds.

"Typical oxygen fluctuations indoors or in city air would be far greater than this," says Mr Langenfelds.

However the oxygen measurements shed new light on the extent to which the world's forests and oceans share the task of absorbing half the carbon dioxide generated by burning of fossil fuels. "While the oceans emerge as the slightly larger long-term sink, plants are clearly soaking up more carbon dioxide with time."

"If they weren't, levels of carbon dioxide would be far higher," says Mr Langenfelds.

Although deforestation during the past 20 years has released vast quantities of carbon dioxide, remaining plants are taking up much of this gas. As plants photosynthesise, they produce oxygen, explaining why the oxygen decline in air has been less than expected.

Researchers speculate that plants today could be growing more rapidly due to warmer conditions, higher carbon dioxide concentrations or increased nitrogen fertilisation. Alternatively, previously cleared land may be returning to forest.

Mr Langenfelds has analysed air dating back to 1978 from CSIRO's unique "archive" of pristine air collected at the remote Cape Grim Baseline Air Pollution Station operated by the CSIRO and Bureau of Meteorology in north-western Tasmania.

In the past, the isotopic composition of carbon dioxide has been used to attempt to distinguish ocean and plant uptake of carbon dioxide from fossil fuel burning.

By analysing both oxygen and carbon isotopes over the 20-year period, Mr Langenfelds and colleagues have identified the problem with previous isotope attempts and reconciled previously conflicting information.

CSIRO's oxygen measurements have been made with technology available only recently and provide an important constraint on identification of the factors that are influencing growth of carbon dioxide in the atmosphere.

Findings based on the decline in oxygen have just been published in the international journal, Geophysical Research Letters.

More information from paul.holper@dar.csiro.au


Story Source:

The above story is based on materials provided by CSIRO Australia. Note: Materials may be edited for content and length.


Cite This Page:

CSIRO Australia. "Oxygen Measurements Yield Greenhouse Clues." ScienceDaily. ScienceDaily, 19 July 1999. <www.sciencedaily.com/releases/1999/07/990719033405.htm>.
CSIRO Australia. (1999, July 19). Oxygen Measurements Yield Greenhouse Clues. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/1999/07/990719033405.htm
CSIRO Australia. "Oxygen Measurements Yield Greenhouse Clues." ScienceDaily. www.sciencedaily.com/releases/1999/07/990719033405.htm (accessed October 1, 2014).

Share This



More Earth & Climate News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: 12 More Bodies Found on Japan Volcano

Raw: 12 More Bodies Found on Japan Volcano

AP (Oct. 1, 2014) — A dozen more bodies were found Wednesday as Japanese rescuers resumed efforts to find survivors and retrieve bodies of those trapped by Mount Ontake's eruption. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com
Raw: Trapped Scientist Rescued from Cave in Peru

Raw: Trapped Scientist Rescued from Cave in Peru

AP (Oct. 1, 2014) — A Spanish scientist, who spent 12 days trapped about 1300 feet underground in a cave in Peru's remote Amazon region, was rescued on Tuesday. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Media, Industry Groups React To Calif. Plastic Bag Ban

Media, Industry Groups React To Calif. Plastic Bag Ban

Newsy (Sep. 30, 2014) — California is the first state in the country to ban single-use plastic bags in grocery, liquor and convenience stores. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins