Gas from the past gives scientists new insights into climate and the oceans

In recent years, public discussion of climate change has included concerns that increased levels of carbon dioxide will contribute to global warming, which in turn may change the circulation in the earth's oceans, with potentially disastrous consequences.

In a paper published today in the journal Science, researchers presented new data from their analysis of ice core samples and ocean deposits dating as far back as 90,000 years ago and suggest that warming, carbon dioxide levels and ocean currents are tightly inter-related. These findings provide scientists with more data and insights into how these phenomena were connected in the past and may lead to a better understanding of future climate trends.

With support from the National Science Foundation, Jinho Ahn and Edward Brook, both geoscientists at Oregon State University, analyzed 390 ice core samples taken from Antarctic ice at Byrd Station. The samples offered a snap shot of the Earth's atmosphere and climate dating back between 20,000 and 90,000 years. Sections of the samples were carefully crushed, releasing gases from bubbles that were frozen within the ice through the millennia. These ancient gas samples were then analyzed to measure the levels of carbon dioxide contained in each one.

Ahn and Brook then compared the carbon dioxide levels from the ice samples with climate data from Greenland and Antarctica that reflected the approximate temperatures when the gases were trapped and with ocean sediments in Chile and the Iberian Peninsula. Data from the sediments provided the scientists with an understanding of how fast or slow the ocean currents were in the North Atlantic and how well the Southern Ocean was stratified during these same time periods.

The researchers discovered that elevations in carbon dioxide levels were related to subsequent increases in the Earth's temperature as well as reduced circulation of ocean currents in the North Atlantic. The data also suggests that carbon dioxide levels increased along with the weakening of mixing of waters in the Southern Ocean. This, the researchers say, may point to potential future scenario where global warming causes changes in ocean currents which in turn causes more carbon dioxide to enter the atmosphere, adding more greenhouse gas to an already warming climate.

Ahn and Brook state that a variety of factors may be at work in the future that alter the relationship between climate change and ocean currents. One potential factor is that the levels of carbon dioxide in today's atmosphere are much higher than they were during the period Ahn and Brook studied. The researchers hope that future studies of the ancient gas from a newly drilled ice core may allow a higher resolution analysis and yield more details about the timing between CO2 levels and the temperature at the earth's poles.

Media Contact

Dana Cruikshank EurekAlert!

More Information:

http://www.nsf.gov

All latest news from the category: Earth Sciences

Earth Sciences (also referred to as Geosciences), which deals with basic issues surrounding our planet, plays a vital role in the area of energy and raw materials supply.

Earth Sciences comprises subjects such as geology, geography, geological informatics, paleontology, mineralogy, petrography, crystallography, geophysics, geodesy, glaciology, cartography, photogrammetry, meteorology and seismology, early-warning systems, earthquake research and polar research.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors