The entire 10,000-year history of civilization has happened in an unusually warm interlude in the Earth’s recent history. Over the past million years, it has been as warm as this or warmer for less than 10% of the time, during 11 brief episodes known as interglacial periods.
…..Our own interglacial period has followed previous ones in having an abrupt beginning and a sharp peak, followed by slow cooling. The question is whether recent warming is a temporary blip before the expected drift into glacial conditions, or whether humankind’s impact on the atmosphere has now reversed the cooling trend.
via Matt Ridley on Ice Ages and Man-Made Warming | Mind & Matter – WSJ.com.