New research has demonstrated how shifted wind patterns caused in the Northern Hemisphere during the last ice age brought warm air to the Southern Hemisphere, ending the ice age.
An excerpt: (read in full here)
“Those winds also brought hot air and warm seawater south from the equator, which caused the beginning of warming in the southern hemisphere, including New Zealand.
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“This mechanism would help scientists explain just what carbon dioxide did in the last ice age: Glaciers New Zealand and Patagonia started melting before the rise in carbon dioxide levels, but the shifting southern hemisphere westerlies could explain that rapid warming.”