Featured Research

from universities, journals, and other organizations

Low Carbon Dioxide Levels In Atmosphere During Glacial Periods May Be Caused By Antarctic Sea Ice

Date:
March 10, 2000
Source:
Scripps Institution Of Oceanography / University Of California, San Diego
Summary:
A new study indicates that variations in Antarctic sea ice may have played a significant role in lowering atmospheric carbon dioxide (CO2) concentrations during the last ice age. This study makes progress towards unraveling the mysteries of the past climate changes, a necessary step for predicting future climate.

A new study indicates that variations in Antarctic sea ice may have played a significant role in lowering atmospheric carbon dioxide (CO2) concentrations during the last ice age. This study makes progress towards unraveling the mysteries of the past climate changes, a necessary step for predicting future climate.

Related Articles


The study by Britton Stephens, a University of Colorado researcher at the National Oceanic and Atmospheric Administration's Climate Monitoring and Diagnostics Laboratory in Boulder, Colo., (formerly of Scripps), and Ralph Keeling of Scripps Institution of Oceanography at the University of California, San Diego, appears in the March 9 issue of Nature and presents a new theory to explain why low carbon dioxide concentrations in the atmosphere are found during glacial periods.

According to ice core records, every hundred thousand years or so, the earth cycles between warm periods and cold glacial periods, with Antarctic temperatures varying by about 20 degrees Fahrenheit. Records also indicate that during the glacial periods there was 30 percent less CO2 in the atmosphere. This study attempts to solve the mystery of the connection between global atmospheric CO2 concentrations and Antarctic temperatures, which seem to rise and fall together. Carbon dioxide is one of the most important greenhouse gases. While it is a naturally occurring gas, it also has been increasing in the atmosphere. Many believe this increase is due to human activities and raises concern about global warming.

While algae and other microscopic plants in the oceans are constantly removing CO2 from the atmosphere as they grow and live, eventually they die and sink, returning the carbon dioxide to the deep ocean. "Thus, the amount of CO2 in the atmosphere depends on how efficiently the water from the deep ocean can return to the surface and release its extra CO2," the authors said.

"Recently we have learned that deep waters primarily return to the surface around Antarctica as opposed to at low-latitudes as was previously believed. Since the waters around Antarctica were mostly covered with ice during glacial periods, that could have prevented much of the CO2 in the surfacing deep waters from leaking back to the atmosphere, thereby lowering atmospheric CO2 concentrations," Stephens said.

The authors constructed a simple computer model that represents the ocean-atmosphere CO2 system and reflected the improved understanding of deep-water circulation.

"When we increased the amount of sea-ice around Antarctica in the model to simulate the glacial state, the atmospheric CO2 concentration decreased by a similar amount as that observed in ice-core records," Stephens said. This result suggests that variations in Antarctic sea-ice may play a significant role in regulating atmospheric CO2 on glacial time scales.

"This is the first study that shows that sea ice can have a significant effect on atmospheric carbon dioxide concentrations," said co-author Keeling. "This may be one of the keys to unraveling the origins of the major climate shifts of the past. It also opens the door to the Southern Hemisphere's control of climate. If sea ice is affecting carbon dioxide in this way, then you can imagine how many ways the Southern Hemisphere may be driving climate change throughout the world."

According to the authors, in order to predict future atmospheric carbon dioxide concentrations and their influence on global climate, "we need to first understand the causes of past carbon dioxide changes."

The study was supported by the National Science Foundation and the Achievement Rewards for College Scientists Foundation.

######

Scripps Institution of Oceanography, at the University of California, San Diego, is one of the oldest, largest, and most important centers for global science research and graduate training in the world. The National Research Council has ranked Scripps first in faculty quality among oceanography programs nationwide. The scientific scope of the institution has grown since its founding in 1903 to include biological, physical, chemical, geological, geophysical, and atmospheric studies of the earth as a system. More than 300 research programs are under way today in a wide range of scientific areas. The institution has a staff of about 1,300, and annual expenditures of approximately $100 million, from federal, state, and private sources. Scripps operates the largest academic fleet with four oceanographic research ships for worldwide exploration and one research platform.


Story Source:

The above story is based on materials provided by Scripps Institution Of Oceanography / University Of California, San Diego. Note: Materials may be edited for content and length.


Cite This Page:

Scripps Institution Of Oceanography / University Of California, San Diego. "Low Carbon Dioxide Levels In Atmosphere During Glacial Periods May Be Caused By Antarctic Sea Ice." ScienceDaily. ScienceDaily, 10 March 2000. <www.sciencedaily.com/releases/2000/03/000310075412.htm>.
Scripps Institution Of Oceanography / University Of California, San Diego. (2000, March 10). Low Carbon Dioxide Levels In Atmosphere During Glacial Periods May Be Caused By Antarctic Sea Ice. ScienceDaily. Retrieved April 21, 2015 from www.sciencedaily.com/releases/2000/03/000310075412.htm
Scripps Institution Of Oceanography / University Of California, San Diego. "Low Carbon Dioxide Levels In Atmosphere During Glacial Periods May Be Caused By Antarctic Sea Ice." ScienceDaily. www.sciencedaily.com/releases/2000/03/000310075412.htm (accessed April 21, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, April 21, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Newsy (Apr. 20, 2015) Five years on, the possible environmental impact of the Deepwater Horizon spill includes a sustained die-off of bottlenose dolphins, among others. Video provided by Newsy
Powered by NewsLook.com
Pee-Power Toilet to Light Up Disaster Zones

Pee-Power Toilet to Light Up Disaster Zones

Reuters - Innovations Video Online (Apr. 20, 2015) Students and staff are being asked to use a prototype urinal to &apos;donate&apos; urine to fuel microbial fuel cell (MFC) stacks that generate electricity to power lighting. The developers hope the pee-power technology will light toilet cubicles in refugee camps, where women are often at risk of assault in poorly lit sanitation areas. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Raw: Undersea Quake Shakes Taiwan

Raw: Undersea Quake Shakes Taiwan

AP (Apr. 20, 2015) A strong undersea earthquake struck between Taiwan and southern Japan on Monday, sparking a house fire that killed a person outside of Taiwan&apos;s capital. (April 20) Video provided by AP
Powered by NewsLook.com
Five Years Later, the BP Oil Spill Is Still Taking Its Toll

Five Years Later, the BP Oil Spill Is Still Taking Its Toll

AFP (Apr. 20, 2015) On April 20, 2010, an explosion and fire on the Deepwater Horizon rig in the Gulf of Mexico started the biggest oil spill in US history. BP recently reported the Gulf is recovering well, but scientists paint a different picture. Duration: 02:36 Video provided by AFP
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