Ancient tree reveals cause of spike in Arctic temperature

A kauri tree trapped in a New Zealand swamp for 30,000 years may have overturned the idea that a slowdown in ocean currents in the North Atlantic may be entirely responsible for Dansgaard-Oeschger events and the characteristic bi-polar see-saw, which sees the Antarctica cool while the Arctic warms during glacial periods. The research reveals a mechanism that generates a 20,000 km long atmospheric bridge, reaching from Antarctica to the Arctic.