Marine cores collected in the western tropical Pacific were used to compare the chronology of Southern Ocean warming near Antarctica and rising CO2 during the last deglaciation. The results provide evidence that the Southern Ocean off Antarctica warmed by ~2°C between 19,000 and 17,000 years before the present, about 1,000 years before the rise in atmospheric CO2.
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.
Global surface temperatures reconstructed over the last deglaciation show that temperature is correlated with but generally lags CO2 concentration. However, at the beginning of the deglaciation a global warming of about 0.3 °C preceded the initial increase in CO2 concentration suggesting that rising CO2 concentration amplified but did not initiate deglacial warming.
In 2009 a widely used dataset indicated that the average temperature of the Earth’s surface may have stopped warming, or that it was warming at a lower rate than the long term average. A new analysis shows that the trend for 1998–2012 is indistinguishable from the best estimate of the long trend for 1951–2012.