Mammoth Melt

The effects of a change in global wind patterns which helped to end the last major ice age were first seen on New Zealand glaciers, according to Columbia University scientists. Mountain glaciers in New Zealand and South America started to melt 18, years ago, at the peak of the last ice age. By 16, years ago the glaciers were in full retreat. Research indicates that westerly winds in the southern hemisphere shifted south, which would have brought warm air and sea water to the mid latitudes and started the warming of the glaciers. Study co-author geochemist Bob Anderson says the studies explain how warming triggered in the north moves to the south, ending an ice age. “Finally, we have a clear picture of the global teleconnections in Earth’s climate system that are active across many time scales,” Anderson says. The Earth enters an ice age about every 1, years as its orientation toward the sun shifts.