Scientists are always finding new ways to collect interesting information. For those studying climate change there are a lot of awesome new opportunities. Not only do we need to understand today’s climate, but we also need to know about the Earth’s ancient climate for the sake of making comparisons. Studying the Earth’s ancient climate is pretty cool on it’s own, but even cooler when you get scientists to look into ancient ice cores. How can studying ice tell us about ocean temperature history? Listen to this Question Your World radio report produced by the Science Museum of Virginia to learn more.
Many scientists have studied air bubbles trapped in Antarctic ice cores to trace back Earth’s atmospheric history. These studies have all concluded that there are more heat trapping gases in the Earth’s atmosphere now than at any other time in the last several million years. We did a whole piece on that if you’re interested in checking that out!
Well, ice core scientists are making news again and this time it's for something quite noble. No, really, they’re literally measuring noble gas levels trapped in ice to understand the history of ocean temperatures.
Gases like Xenon and Krypton don’t really react with anything in the air or on land, and living organisms don’t use them in their life cycles. The only thing that changes their relative amounts in the atmosphere is the temperature of the oceans.
When oceans warm up, they don't absorb a lot of of krypton and xenon, and thus their amount in the air increases. On the other hand, when oceans cool down, more of these gases get absorbed by water, and the amount in the air decreases. Some of that water ends up trapped as ice and thus holds the Earth’s nobel gas levels as a time capsule.
Scientists can now measure these nobel gas levels directly from the air bubbles trapped Antarctic ice. A team of international scientists recently measured the changes of nobel gas levels in ice cores dating back to the end of the last ice age, about 20,000 years ago. What did they find? The ocean warmed up by over 4.5°F from the ice age to when scientists think humans started civilizations.
This warming took well over 10 thousand years to take place – much longer than the scale of warming we’re observing today. This further supports the global science community’s concerns regarding the amount of heat trapping gases that we continue to put into our atmosphere.
Ice core science is a cutting edge way to better understand our Earth’s ancient atmosphere, to help put a historic context to present day climate data, and to provide information for us to plan for future resiliency options.
Much like the gasses they’re studying, this process too is quite noble.