Ice core leads to discovery of new greenhouse gas

Researchers in geosciences, ocean sciences benefit from information on methane, CO2

By: Daniel Acee

Posted: 5/23/08

A new discovery in greenhouse gases and climate effects has surfaced from an ice core obtained in Antarctica that dates back 800,000 years.

The ice core has provided researchers in geosciences and ocean sciences with valuable information that shows patterns of methane, carbon dioxide and temperature levels over that large amount of time.

Edward Brook, associate professor for the OSU geosciences department, was chosen by the weekly science journal "Nature" to write a column about the ice core that was found by the European Project for Ice Coring in Antarctica.

"Direct evidence of past environmental conditions is rare, which makes it all the more valuable where it does occur," said Brook in his article for "Nature." "The EPICA collaboration presented the latest, and longest, record from perhaps the most valuable of these archives: the atmospheric gases trapped and preserved in ice cores extracted from Earth's polar regions."

The ice core is created as snowfall weighs down on itself increasing over time, according to Brook.

This puts constantly increasing pressure on lower snow layers. The layers eventually packed down with great force and sinter together, a geological process that causes powders to form a coherent mass, eventually trapping the air bubbles from each time period into solid ice.

Using a specifically designed drill, teams of scientists spend, at times, up to five years removing six-meter long sections of ice core at a time measuring about 12 centimeters in diameter.

"A relatively small band of international scientists are gradually drilling further down into the ice cap and progressively analyzing older ice cores," Brook said in his article.

Brook has dealt with many skeptics saying that humans have no correlation to the increase in carbon dioxide levels, which are warming up Earth's climate.

"What we are trying to do is to understand gases on many time scales, over thousands of years," Brook said.

A graph of the gases and temperatures found in the ice core shows a spike in methane, carbon dioxide and temperature levels just after the industrial revolution.

This provides valid information about the start of fossil fuel burning.

Carbon dioxide sat at an averaged level of 300 parts per million over the past 800,000 years.

Once the industrial revolution began, the average moved up to 382 ppm. Methane averaged 800 parts per billion and now have reached 1800 ppb.

Brook and others are attempting to find the patterns of climate change over the entirety of Earth's history.

"Something has to happen to the Earth's system to raise CO2 levels," Brook said.

"If we found gas and temperature levels to be the same then as they are today, we could say that the greenhouse effects are not ours, but we jacked these levels up so fast we're just waiting for Earth to respond."

Data from the ice core has reinforced the tight link between greenhouse gases and climate.

This link is shown through reactions that the earth has shown since greenhouse gases have started to rise.

"I get a lot of e-mails from skeptics that try to tell me that humans have no direct relation to the increase in carbon dioxide," Brook said. "There is a lot of misinformation out there about how science works, but none of it adds up."

According to Brooks, OSU has a group of a dozen professors that are passionate about studying the earth's past climates.

"I like this field because it's a global issue, these are the workings of the entire earth," said Brooks. "Its fascinating to just ponder how this all works together. This isn't just an academic issue, it effects all of us."

James Lee is a member of Brook's research team and enjoys having Brook as a boss.

"It's really interesting to watch the progression and changes [of gases and temperatures] over time," Lee said. "You can see epic events that happened throughout history in terms of methane levels."

"I was not totally aware about it [Brook's article in "Nature"], he's very modest and doesn't talk about it a lot, he gets published fairly frequently though," Lee said.

If you are interested in learning more about greenhouse gases and new discoveries in the geosciences and oceanography fields visit science.oregonstate.edu/~brooke

Daniel Acee, senior reporter

news@dailybarometer.com