Pharos-Tribune

Opinion

June 21, 2013

New ice cores shed more light on climate

Late in the last century scientists published reams of data about Earth’s climate derived from ice cores taken from Greenland and Antarctic glaciers. By drilling down into the ice with hollow bits (think of using a spinning pipe as a drill) workers were able to pull columns of ice up to the surface. The material brought to light in this way was very special for several reasons.

First, the ice cores show annual layers going back in time. That means scientists can count backwards through time from the surface downward, a bit like school kids can count the rings of a tree, measuring out history year by year.

The ice in the cores had originally been snow at the surface, snow that was buried by later snows and slowly became compacted to form a coarse icy material called “firn” and then glacial ice itself. The ice has tiny bubbles of air in it, air that was trapped in the snow layers in times gone by. This means that scientists can analyze the small air samples that are sealed in the ice and determine the composition of the air that was blowing around the Earth in past millennia.

Chemical analyses of the air in the glacial ice show that our planet’s atmosphere has gone through cycles of changes over thousands of years. In particular, the concentration of greenhouse gases like carbon dioxide and methane (the main ingredient in natural gas) has varied over time. The specific dates of the changes can be determined by counting up the layers in the ice core – a pretty nifty trick.

If the only thing the ice cores told us was how much Earth’s air has changed, that would be interesting in itself. But scientists are also able to analyze the ice and from it infer a couple of things.

Text Only | Photo Reprints
Opinion
  • THEIR VIEW: Littering shows disregard for surroundings Numbers tell a sad story about the disregard many Hoosiers have for their surroundings. Too many in Indiana don't care enough about the environment to prevent them from cluttering the countryside by carelessly tossing litter along the side of roadway

    April 18, 2014

  • WOLFSIE: High-tech got you down? I love where I bank. It's a branch inside of a big supermarket. I can make a modest withdrawal and then go and blow every last penny in the cookie aisle. The tellers at the window appreciate me. They know about my obsession with round numbers and und

    April 18, 2014

  • PETERS: Grizzly bear may help human medicine I've gained 5 pounds since last summer. My body mass index (BMI) is still fine, but I need to stop gaining to keep it that way. Grizzly bears put my weight gain to shame. In the late summer, they eat some 50,000 calories per day and gain more than 1

    April 18, 2014

  • THEIR VIEW: Lawmakers fail to act on the issue After several years of fretting over Indiana's ongoing methamphetamine problem, the Indiana General Assembly continues to struggle for a solution. The issue seems to come up every session, given that Indiana leader the nation in meth lab seizures. Bu

    April 17, 2014

  • WILLIAMS: Feelings of the flowers I took one of those fun tests on Facebook to see what kind of flower I am and lo and behold, it said I was an orchid! That is so wrong because I have always thought I was the exact opposite of an orchid. I'd characterize myself as a daisy. You know,

    April 17, 2014

  • HAMILTON: Government as innovator? You bet! Five years ago, the federal government spent $169 billion to fund basic research and development. This fiscal year, it's down to $134 billion. People who believe in public belt-tightening applaud drops like that. I understand why: there are many reas

    April 17, 2014

  • PARKER: It's time to take a joke, America In selecting Stephen Colbert to replace David Letterman as host of the "Late Show," CBS has waged war on America's Heartland -- or so proclaims that Palm Beach font of heartland mirth, Rush Limbaugh. Don't you believe it, Heartlanders. But wait, ther

    April 16, 2014

  • THEIR VIEW: Constitutional convention won't work today There seems to be a growing idea that we need a Constitutional convention. That, of course, is the other way to change the Constitution. Amendments have been used 27 times to make changes, ranging from limiting the president's term of office to the d

    April 16, 2014

  • KITCHELL: Forum about adding answers, subtracting questions A week from tonight, Logansport residents and those outside Logansport who purchase electricity from the Logansport Municipal Utilities will have a chance to find out some things for themselves. A free forum at McHale Performing Arts Center will feat

    April 16, 2014

  • PUBLIC FORUM: The people are losing control of its government The people are losing control of government President Obama and progressive Democrats and Republicans are changing the landscape of our country by bypassing our Constitution and what our forefathers fought and gave their lives for. Their philosophy c

    April 16, 2014

Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
Poll

Should mushroom hunters be allowed to forage off-trail in Indiana state parks?

Yes
No
Undecided
     View Results
Featured Ads
AP Video
Parade
Magazine

Click HERE to read all your Parade favorites including Hollywood Wire, Celebrity interviews and photo galleries, Food recipes and cooking tips, Games and lots more.