ambience: Sound of climate change
We’re listening to one thousand years of climate change, translated into sound. Using a variety of techniques, scientists have been able to take the average temperature of the earth’s atmosphere every year for the past thousand years. What we’ve done is assign a different musical note to represent each year’s number. The higher the temperature, the higher the tone. I’m Jim Metzner, and this is the Pulse of the Planet, presented by DuPont.
Now, to get one-thousand years of climate data, scientists have had to turn to ancient archives. But you won’t find these kinds of archives in a library.
“What we call climate archives are natural phenomena that have in some way recorded how the temperature or the climate has varied in the past. The most familiar of these would be tree rings where if you look at a section of a tree that’s been cut down you can see the individual rings and how they vary from year to year.”
Raymond Bradley is the head of the department of Geosciences at the University of Massachusetts in Amherst. He says that while trees can play historian in some cases, they may not be the most reliable natural archive in others. For example, such things as changes in soil can affect a tree’s growth.
“Other natural archives have been used, and among the most important are ice cores from polar regions where we have a yearly accumulation of snowfall. And in that snow fall there are measurements we can make that help us estimate how temperatures have varied in the past.”
To a geoscientist, a polar ice sheet is a record of ancient atmospheric processes. Bubbles of air, like mini atmospheric time capsules, are captured under cumulative layers of ice and snow. By drilling deep into glaciers, and extracting core samples, scientists are able to track and date historic changes in the atmosphere.
Pulse of the Planet is presented by DuPont, bringing you the miracles of science, with additional support provided by the National Science Foundation.