by W. Jones, January 22, 2020 in ClimateChangeDispatch
Did you know that over the last 450,000 years there have been four Ice Ages lasting around 100,000 years each?
And five interglacial periods lasting around 12,000 years each?
Look at this graph of temperature data derived from the Vostok ice core from Antarctica.
What it means is that for around 90 percent of the last 450,000 years Earth has been in an Ice Age, where global temperatures have slumped to as low as 10 deg C colder than in the relatively brief interglacial periods.
The current interglacial period (the fifth) began about 11,600 years ago, suggesting it may not last much longer. It corresponds to the time when human beings began farming and building cities and civilizations.
It is notably cooler than the previous four interglacial periods. If we ‘zoom in’ on it (see the upper graph, below)