Ancient ice indicates recent and rapid CO2 rise
Ed Brook holds up a small section of an ancient ice core filled with tiny bubbles of trapped air from when it was originally frozen. A recent deep ice core from Antarctica showed that levels of CO2 - a greenhouse gas - have risen faster in the past two centuries than in the previous 650,000 years. What's more, CO2 concentrations in Earth's atmosphere today are 27% more than anything in the ice record.
DB: This is Earth & Sky. Earlier on this program, we reported on the work of European scientists who drilled deep into the Antarctic continent to retrieve ancient ice.
JB: They drilled down three kilometers – about two miles – and retrieved ice more than 650,000 years old. Locked in that buried ice were bubbles of atmosphere – including some greenhouse gases – from Earth?s past. Here’s ice core expert Ed Brook of Oregon State University.
Ed Brook: We have not observed, in the pre-industrial record of greenhouse gases, changes in the levels of CO2 and methane that are as rapid as the changes of the industrial revolution.
DB: In other words, ice core studies reveal how fast greenhouse gas levels can go up and how quickly climate can change as a consequence. It seems, over the last 650,000 years, levels of CO2, a greenhouse gas, have never risen as fast as they have in the past two centuries. What’s more, CO2 concentrations in Earth’s atmosphere today are 27% more than anything on the ice record.
Ed Brook: So the atmosphere is changing these days much more quickly than it seems to have been able to naturally. And that’s an important observation, because it tells us that we are doing something very different to the climate system than any natural variations could do. And that should give us pause to think about what the consequences might be.
JB: We have pictures of ancient ice at earthsky.org. Thanks today to NOAA ? the National Oceanic and Atmospheric Administration. We’re Block and Byrd for Earth & Sky.
Thanks to:
Edward Brook
Associate Professor of Geosciences
Oregon State University
Corvallis, OR
Mark Twickler
Climate Change Research Center
Institute for the Study of Earth, Oceans, and Space
University of New Hampshire
Durham, NH
Additional Teacher Resources
New Scientist: Record ice core reveals Earth’s ancient atmosphere
The European Project for Ice Coring in Antarctica (EPICA) team has spent years drilling the ice core in Antarctica’s Ice Dome Concordia. They had previously analysed its record of global temperatures, but have just completed the detailed analysis of the trapped air. The bubbles record how the planet’s atmosphere changed over six ice ages and the warmer periods in between.
European Sceince Foundation: European Project for Ice Coring in Anarctica
EPICA is a multinational European project for deep ice core drilling in Antarctica. Its main objective is to obtain full documentation of the climatic and atmospheric record archived in Antarctic ice by drilling and analyzing two ice cores and comparing these with their Greenland counterparts. Evaluation of these records will provide information about the natural climate variability and mechanisms of rapid climatic changes during the last glacial epoch.
