While political leaders from around the world meet in Copenhagen this week to set international policy to control global warming, climate scientists are trying to determine what changes are needed by unlocking clues from glaciers.
Studying nature remains critical to shaping answers to the problem, they say.
Joerg Schaefer, a Columbia University climate scientist, and his team are working to develop a global map dating from the last ice age through present day, depicting the way glaciers have moved over time in reaction to climate changes.
“Glaciers are extremely sensitive to even the smallest climate signals,” said Schaefer, who started his career as a geochemist. “In the glacier and moraine record, you see signals you don’t see in any other record.”
Comparing those movements on interhemispheric and regional levels will help climate scientists and policymakers understand how the hemispheres, climate shifts and glaciers are coupled, he said.
The information is crucial because glaciers are linked to water supply.
“[We want to] provide [glaciologists] with the information that is relevant to predict at what speed glaciers in certain areas will disappear and modify the water availability and the hydropower,” Schaefer said. “In many areas it’s a big problem already.”
Richard Alley is a climate change expert at Pennsylvania State University. (Diane Rusignola/MNS)
Pennsylvania State University climate geologist Richard Alley, also a glacier expert, agrees that understanding the history of climate change around the world is one of the best ways scientists can learn about contributing factors like atmospheric and oceanic circulation.
Glacier experts also study the important role winds play in climate change. When winds shift, oceans shift in response, causing deep waters from the South to come up at an increased rate and release additional carbon dioxide into the air.
This process warms the Southern hemisphere while the North still stays in the cold. Scientists such as Schaefer are trying to show evidence of why the process occurs and to create a historical map using geological records.
“If that is true, this mechanism, then we have to see it in the glacial and the moraine record because the South has to be different than the North,” Schaefer said.
But add enough carbon dioxide and the North gets warm, too. Carbon dioxide levels now are at 385 parts per million, the highest levels in hundreds of thousands of years.
Scientists know that because climate geologists such as Alley measure the CO2 in ancient air pockets captured in ice cores drilled from the glaciers.
The field work in understanding the effects of glaciers, wind and other forces of nature on the climate – and the effects of the population on these forces of nature – is a key factor in addressing climate change, these scientists believe.
“As long as we don’t have… artificial trees, and as long as there’s coal in the ground, we are going to be having this discussion,” Alley said. “[But] we are going to change the world in really fundamental ways.”