A team of researchers recently analyzed an exhaustive catalog of geologic samples -- including ice cores, tree rings and coral, as well as ocean and lake sediments -- dating back to the year 900. Using sea-surface and atmospheric temperature data derived from the samples, scientists were able to plot a history of ocean current behavior.
The findings suggest the current slowdown is not only the most dramatic in recorded history, but also well outside the norm -- enough to suggest it is not part of natural fluctuation.
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