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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.
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.
As the Earth warms, permafrost soils melt and this old carbon is released into the atmosphere as methane and CO2. Using radiocarbon dating of methane bubbles and soil organic carbon from lakes formed by melting thermafrost in Alaska, Canada, Sweden and Siberia combined with remote sensing it is found that methane and carbon dioxide releaed in the Arctic region during the past 60 years is much less than the CO2 contributed annually from anthropogenic and other sources.
During the last deglaciation there was several episodes of rapid and substantial sea level rise. A recent study has found that during one of these, sea level rose by about 17 meters over a period that does not exceed 350 years, but could be as low as a century.