Sid PerkinsEarth’s ice ages are typically thought of as seemingly unending periods of bitter cold. But a new study suggests bursts of carbon dioxide (CO2) often entered the atmosphere during these times, providing decades or even centuries of relative warmth amid 10,000-year stretches of chill.
Such pulses may have caused glaciers and ice sheets to retreat somewhat, thus opening up new areas for plants and animals.Researchers can track fluctuations in atmospheric CO2 by looking at ice cores drilled in Antarctica, Greenland, and some tall mountains in lower latitudes.
The cores contain trapped air bubbles as fluffy snow was compressed into ice by the weight of newer, fresher overlying layers.Some of these climate chronicles go back hundreds.