A recent study has created a simple mathematical rule that can account for the timing of the onset of interglacials following ice ages over the past three million years. The rule is based on predictable long-term astronomical variations in the Earth’s orbit and tilt called Milankovitch cycles.
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.
A reanalysis of the effect of black carbon emissions has found that it is second only to carbon dioxide emissions in its warming impact on the climate. Together carbon dioxide, black carbon, and methane emissions represent the anthropogenic sources with the largest impact on Earth’s climate.
It is known that orbital forcing is involved in glacial/deglacial cycles but is insufficient by itself to explain the glacial/deglacial cycles. This study argues that a biological feedback mechanism kicks in when a threshold is reached and together with orbital forcing results in the sustained and rapidly increasing CO2 and surface temperature of a deglaciation.