Do you see the bubbles in this piece of Antarctic ice? The bubbles contain carbon dioxide and other gases that were trapped in the ice when formed thousands of years ago. Researchers carefully crush the piece and capture the gases that escape when the bubbles break. This allows them to better understand what carbon dioxide levels were over time.
Click on image for full size
Courtesy of Oregon State University
Gas From the Past Gives Scientists New Insights into Climate and the Oceans
News story originally written on October 3, 2008
To learn what Earth’s atmosphere used to be like, scientists have been studying ancient air.
The ancient air is within tiny bubbles in 390 samples of ice from Antarctica. The bubbles tell what Earth's atmosphere was like 20,000 to 90,000 years ago.
Today, as the amount of greenhouse gases in Earth’s atmosphere continues to grow and the greenhouse effect gets stronger, scientists are concerned that this may cause a change in the circulation of the ocean. Comparing the data from the air bubbles with other data about what the planet was like at that time, scientists are able to learn whether this has happened in the past.
Interested in learning more about the connection greenhouse gases, climate, and ocean circulation, scientists Jinho Ahn and Edward Brook analyzed the bubbles. Sections of the samples were carefully crushed, releasing gases from the little bubbles. The level of carbon dioxide in each ancient gas sample was measured.
The scientists compared the amounts of carbon dioxide found in the ancient air with climate information about the temperature of our planet at the time when the gases were trapped in the ice. They also compared the carbon dioxide levels from the ancient air with ocean sediments in Chile and the Iberian Peninsula. The sediments preserve evidence of how fast or slow the ocean currents were.
What did they find? The data suggests that carbon dioxide levels, global warming, and ocean currents are tightly related. They found that samples of ancient air that contained more carbon dioxide were from times when Earth’s temperature was higher. They also found that these were times when ocean currents were weaker.
And if it has happened in the past, it may happen in the future, say the scientists. And changes in ocean currents could cause even more carbon dioxide to get into the atmosphere.
Last modified January 11, 2009 by Lisa Gardiner.
Shop Windows to the Universe Science Store!
Our online store
includes fun classroom activities
for you and your students. Issues of NESTA's quarterly journal, The Earth Scientist
are also full of classroom activities on different topics in Earth and space science!
You might also be interested in:
Frozen water is found in many different places on Earth. Snow blankets the ground at mid and high latitudes during winter. Sea ice and icebergs float in the chilly waters of polar oceans. Ice shelves fringe...more
Antarctica is unique. It is the coldest, windiest, and driest continent on Earth. The land is barren and mostly covered with a thick sheet of ice. Antarctica is almost entirely south of the Antarctic Circle...more
Even though only a tiny amount of the gases in Earth’s atmosphere are greenhouse gases, they have a huge effect on climate. There are several different types of greenhouse gases. The major ones are carbon...more
Energy from the Sun that makes its way to the Earth’s surface can have trouble finding its way back out to space. This is because of a natural process called the greenhouse effect. Without the greenhouse...more
The climate where you live is called regional climate. It is the average weather in a place over more than thirty years. To describe the regional climate of a place, people often tell what the temperatures...more
The world has several oceans, the Pacific, the Atlantic, the Indian, the Arctic, and the Southern Ocean. While we have different names for them, they are not really separate. There are not walls between...more
Carbon dioxide (CO2) is a kind of gas. There isn't that much carbon dioxide in Earth's atmosphere, but it is still very important. Carbon dioxide is a greenhouse gas. That means it helps trap heat coming...more