Ice age, interrupted

Research shows that a new ice age could well have been upon us in the next millennium were it not for increases in CO2 due to humans, despite the advantageous trend in solar radiation of our current age. Our work suggests that natural insolation will not be cancelling the impacts of man-made global warming." - —Dr Luke Skinner In terms of the ebb and flow of the Earth's climate over the course of its history, the next ice age is starting to look overdue. Periods between recent ice ages, or 'interglacials', average out to be around 11 thousand years, and it's currently been 11, 600 since the last multi-millennial winter. Although it is almost impossible to predict exactly when the next ice age will occur (if it will at all), it is clear that a global freeze is not on the horizon; the amount of CO₂ emitted by human activity and the enhanced greenhouse effect that results all but preclude it. But what if we weren't around and CO2 was lower? In a paper published this week, new research proposes that the next ice age would have been kick-started sometime in the next thousand years, just round the corner in the context of the Earth's lifespan, if CO₂ was sufficiently low. By looking at the onset of abrupt flip-flops in the temperature contrast between Greenland and Antarctica (extreme climate behaviour that would have only been possible if vast and expanding ice sheets were disrupting ocean circulation), the researchers believe they have been able to identify the fingerprint of an ice age activation,or the 'glacial inception'.