Antarctica Ice Cap
Irrefutable Evidence of Climate Change
Adapted from an
article: Dr. T.H. Jacka, Glaciology Program,
Antarctic Cooperative Research Centre and
Australian Antarctic
Division.
For the original article see: http://www.chem.hope.edu/~polik/warming/IceCore/IceCore2.html
The snow near the surface of the ice sheet is like a sponge with channels of air between the snow grains. As more and more snow is accumulated on top, the underlying snow is compressed into ice and the air forms bubbles in the ice. Ice cores therefore can be analyzed not just for the chemical and physical properties of the ice, but also for the properties of the air trapped in the ice. These bubbles are actual samples of the atmosphere up to thousands of years ago. So, analysis of them can tell us much about the atmosphere in the past.
Concentrations of carbon dioxide and methane can be measured in the air bubbles trapped in the ice. Carbon dioxide and methane are greenhouse gases and the similarity between the graphs for their concentrations and the temperature change indicates that the greenhouse effect is real. Has there been a significant increase in the atmospheric concentration of greenhouse gases since the industrial revolution?
The answer is yes, as can be seen from the graph below
which shows the concentrations of carbon dioxide in the atmosphere, measured in
the bubbles from an Antarctic ice core from Law Dome near