150,000 y.a. - cold, dry full glacial world
around 130,000 y.a. - rapid warming initiates the Eemian interglacial (Stage 5e)
130,000-110,000 y.a. - global climates generally warmer and moister than present, but with progressive cooling to temperatures more similar to present.
(except for possible global cold, dry event at 121,000 y.a.)
?110,000 y.a. - a strong cooling marks the end of the Eemian interglacial (Stage 5e).
105,000-95,000 y.a. - climate warms slightly but still cooler and drier than present; strong fluctuations.
95,000 - 93,000 y.a. - another cooler phase similar to that at 110,000 y.a.
93,000 - 75,000 y.a. - a milder phase, resembling that at 105,000-95,000 y.a.
75,000 - 60,000 y.a. - full glacial world, cold and dry (the 'Lower Pleniglacial' or Stage 4)
60,000 - 25,000 y.a. - 'middling phase' of highly unstable but generally cooler and drier-than-present conditions (Stage 3)
25,000 - 15,000 y.a. - full glacial world, cold and dry; Stage 2 (includes the 'Last Glacial Maximum')
(This period includes two 'coldest phases' - Heinrich Events - at around 23,000-21,000 y.a. and at 17,000-14,500 y.a.)
14,500 y.a. - rapid warming and moistening of climates in some areas. Rapid deglaciation begins.
13,500 y.a. - nearly all areas with climates at least as warm and moist as today's
12,800 y.a. (+/- 200 years)- rapid onset of cool, dry Younger Dryas in many areas
11,500 y.a. (+/- 200 years) - Younger Dryas ends suddenly, back to warmth and moist climates (Holocene, or Stage 1)
9,000 y.a. - 8,200 y.a. - climates warmer and often moister than today's
about 8,200 y.a. - sudden cool and dry phase in many areas
8,000-4,500 y.a. - climates somewhat warmer and moister than today's
Since 4,500 y.a. - climates fairly similar to the present
Warmth. Around 130,000-110,000 years ago (the Eemian interglacial), the Earth's climates were generally much like those of today, though somewhat warmer and moister in many regions. The climate record derived from long ice cores taken through the Greenland ice cap suggested that the warm climate of the Eemian might have been punctuated by many sudden and fairly short-lived cold phases, but these results are now thought of as inaccurate because the lower layers of the ice sheet have become buckled and jumbled up. However, at least one major cold and dry event during the Eemian seems to be corroborated by the terrestrial pollen record from Europe and China (Zhisheng & Porter 1997). The issue remains controversial, as this review article explains.
Cooling. Though the time at which the Eemian interglacial ended is subject to some uncertainty (it was probably around 110,000 years ago), what does seem evident from the sediment records that cross this boundary is that it was a relatively sudden event and not a gradual slide into colder conditions taking many thousands of years. The recent high-resolution Atlantic sediment record of Adkins et al (1997) suggests that the move from interglacial to much colder-than-present glacial conditions occurred over a period of less than 400 years (with the limitations on the resolution of the sediment record leaving open the possibility that the change was in fact very much more rapid than this).