Last Interglacial

The Last Interglacial is known as the Ipswichian in the UK, the Mikulino (also spelled Milukin) interglacial in Russia, the Valdivia interglacial in Chile and the Riss-Würm interglacial in the Alps. Depending on how a specific publication defines the Sangamonian Stage of North America, the Last Interglacial is equivalent to either all or part of it.

The period falls into the

Global temperatures

The Last Interglacial climate is believed to have been warmer than the current Holocene.^[8][9] The temperature of the Last Interglacial peaked during the early part of the period, around 128,000 to 123,000 years Before Present, before declining during the latter half of the period.^[10] Changes in the Earth's orbital parameters from today (greater obliquity and eccentricity, and perihelion), known as Milankovitch cycles, probably led to greater seasonal temperature variations in the Northern Hemisphere.^{[citation needed]} As the Last Interglacial cooled, pCO₂ remained stable.^[11]

During the northern summer, temperatures in the Arctic region were about 2–4 °C higher than in 2011.^[12] The Arctic Last Interglacial climate was highly unstable, with pronounced temperature swings revealed by δ¹⁸O fluctuations in Greenlandic ice cores,^[13] though some of the instability inferred from Greenland ice core project records may be a result of mixing of Last Interglacial ice with ice from the preceding or succeeding glacial intervals.^[14]

The warmest peak of the Last Interglacial was around 125,000 years ago, when forests reached as far north as

Meltwater pulse 2B, approximately 133,000 BP, substantially weakened the Indian Summer Monsoon (ISM).[24]

Trees grew as far north as southern

Interglacial conditions ended on Antarctica while the Northern Hemisphere was still experiencing warmth.[26]

Sea level

Sea level at peak was probably 6 to 9 metres (20 to 30 feet) higher than today,[28]^[29] with Greenland contributing 0.6 to 3.5 m (2.0 to 11.5 ft),^[30] thermal expansion and mountain glaciers contributing up to 1 m (3.3 ft),^[31] and an uncertain contribution from Antarctica.^[32] A 2007 study found evidence that the Greenland ice core site Dye 3 was glaciated during the Last Interglacial,^[33] which implies that Greenland could have contributed at most 2 m (6.6 ft) to sea level rise.^[34][35] Recent research on marine sediment cores offshore of the West Antarctic Ice Sheet suggest that the sheet melted during the Last Interglacial, and that ocean waters rose as fast as 2.5 meters per century.^[36] Global mean sea surface temperatures are thought to have been higher than in the Holocene, but not by enough to explain the rise in sea level through thermal expansion alone, and so melting of polar ice caps must also have occurred.

Because of the sea level drop since the Last Interglacial, exposed fossil coral reefs are common in the tropics, especially in the Caribbean and along the Red Sea coastlines. These reefs often contain internal erosion surfaces showing significant sea level instability during the Last Interglacial.^[37]

Along the Central Mediterranean Spanish coast, sea levels were comparable to those of the present.^[38] Scandinavia formed an island due to the area between the Gulf of Finland and the White Sea being drowned. Vast areas of northwestern Europe and the West Siberian Plain were inundated.^[39]

Definition of the Last Interglacial