In contrast to West Antarctica where several large glaciers have been losing ice for decades, East Antarctica glaciers have exhibited little evidence of ice loss but NASA’s latest detailed maps of East Antarctica ice velocity and elevation show that a number of glaciers have begun to lose ice over the past decade.
The last deglaciation was characterized by increases in surface temperatures of 10-15 °C punctuated by millennial-scale warming/cooling periods, pulses of increasing atmospheric carbon dioxide and asynchronously increasing methane. A geospatial-temporal variance analysis reveals a global warming trend correlating with rising CO2 on which is superimposed second trend millennial-scale regional warming/cooling periods associated with variation in the strength of the Atlantic overturning current.
New evidence from analyzing fossil plankton shells has revealed that CO2 concentration in the Earth’s atmosphere was about triple current levels around 52 million years ago. It then declined to levels close to current atmospheric CO2 concentration 34 million years ago when Antarctica began to glaciate.
During the last deglaciation atmosphere CO2 concentration rose by about 80 ppm amplifying climate warming. This study of radiocarbon in deep sea corals found that Southern ocean deep water was radiocarbon-depleted throughout the last ice age, but this depletion disappeared between 16,600 and 14,600 years ago consistent with Southern Ocean CO2 outgassing that corresponded to the first pulse of increased atmospheric CO2 early in the deglaciation.