Southern Hemisphere

Climate state

Last Glacial Maximum

Holocene

Climatology

Ice sheet

Climate model

Northern Hemisphere

Global warming

Geology

Climate change

Teleconnection

Abrupt climate change

Oceanography

Paleontology

El Niño Southern Oscillation

Effects of global warming

Glacial period

Nature

An Antarctic ice core reveals that, during the last ice age, the topography of Northern Hemisphere ice sheets shifted tropical Pacific convection eastward, increasing climate variability in the high southern latitudes. During glacial maxima, ice covered vast areas of the Northern Hemisphere and had a broad influence across the global climate system. Tyler Jones and colleagues show that climate variability in the Southern Hemisphere was influenced by these large Northern Hemisphere ice sheets and was about twice as high during the Last Glacial Maximum than in the warmer Holocene that followed. The ice sheets created more elevated and brighter surfaces than at present and this altered the location of tropical convection and the atmospheric pathways that link the tropics to West Antarctica. The results reveal the intimate climatic link between the high latitudes, and the key role of the tropics as an interhemispheric mediator. The presence of large Northern Hemisphere ice sheets and reduced greenhouse gas concen...

Southern Hemisphere climate variability forced by Northern Hemisphere ice-sheet topography