High-resolution Greenland ice core records reveal two warming events at the end of the last ice age involved warming of more than 10 °C. Furthermore the warming transition beginning 14,700 years ago occurred within only three years.
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.
A recent study of ice cores from Antarctica provides a climate record for the past 800,000 years. The analysis reveals that atmospheric carbon dioxide was strongly correlated with Antarctic temperature throughout eight glacial cycles.
Northern permafrost soils represent the largest terrestrial organic carbon pool on Earth. A study the northern circumpolar permafrost zones reveals that landscapes susceptible to abrupt thawing with the release of significant quantities of carbon dioxide and methane cover 20% of the northern permafrost region and store up to half its soil organic carbon.