Zealandia switch: New theory of regulation of ice age climates

Abrupt shifts of the Southern Hemisphere westerly winds, paced by subtle variations in Earth's orbit, lie at the heart of ice age cycles, according to an international research team. This 'Zealandia Switch' hypothesis differs from the long-held view that orbital influences on the extent of Northern Hemisphere continental ice sheets regulate ice age climates. Southern Hemisphere westerlies regulate the exchange of CO2 and heat between the ocean and atmosphere, exerting further influence on global climate.