Ice Reveals Climate History

Over the next three summers in Greenland, a group of international scientists will unearth samples of the country’s ice core down to its very bedrock, in the hopes of painting a complete picture of Earth's changing climate. Each layer provides a dated mixture of water and air bubbles that were trapped in the snow, Thomas L. Friedman writes in the New York Times.

Those bubbles can give scientists such information as what the temperature was, and the amount of greenhouse gases in the atmosphere. So far, the samples reveal a complex system capable of drastic and sudden change. But that doesn't absolve humans, Friedman notes. We shouldn't be contributing to climate change, because we could "tip the balance."
(More polar ice caps stories.)