When the 65N insolation started increasing 20,000 years ago the continental ice sheets melted. In a few thousand years the sea level increased nearly 100m (330 ft).

The Earth's temperature responded to the higher summer insolation in the Northern Hemisphere by warming. This caused the glacial continental ice sheets to melt early in the Holocene Interglacial.

The Holocene and Eemian interglacials. EPICA (Antarctica) ice core.

Interglacial year as defined by an insolation anomaly of zero for 65N summer insolation. The Holocene is currently at interglacial year 16,000.

GRIP (Greenland Ice Core Project) reconstruction of the past 10,000 years.

The Hans Tausen Ice Cap in Peary Land, Greenland is 4,000 years old. It is separate from the main ice sheets that cover Greenland.

The nearly half kilometer thick glacier between Mount Bona and Churchill is ~2,500 years old. Strong proof that this area has cooled in that period of time.

Mt. Logan in Canada was also drilled to bedrock in 1988. Many parts of the glacier are only a few hundred years old, but in places it is up to 8,000 years old.

The Quelccaya Ice Cap in Peru has been used repeatedly as proof of global warming as it has retreated in recent years. What isn't mentioned is that the ice cores to bedrock only date back 1,500 years.

Penny Glacier-Baffin Island. Average of each 1,000 year period is shown as well. Insolation has been dropping the past 10,000 years.

Even in Antarctica the ice cores are starting to show that the warmth of the Holocene is fading.

NGRIP and EPICA ice cores from the Eemian. Insolation drops affect first the NH and then the SH. The rate of temperature change in the NH is greater as well than the SH.

The Eemian cooling took place more quickly, but the Holocene cooling is clear over the past 7,000 years in Greenland.

NGRIP Ice core shows an 8,000 year cooling trend in Greenland.

This chart was used in "An Inconvenient Truth" to minimize the Medieval Warm Period. A careful reader will notice that in the modern time there is simultaneously warm and cold periods. This is because there are two sets of data overlaying. Neither one is from an ice core.

(Antarctica) Vostok and EPICA, (Greenland) GRIP, NGRIP, GISP-2. All of them show significant natural variation in temperature. The purpose of this graph is to show the scale of natural variation.

Same chart as before, but with the modern instrument records overlaying the historic ice cores.

EPICA ice core from four periods when the Earth was in an interglacial and the insolation anomaly went negative. In all cases the long-term trend in temperature was negative.

This is a reconstruction from GISP-2 (Greenland). It does not show global temperatures, it shows the Arctic temperatures. Since that is the region that has shown the MOST variability over the past 2.6 million years, it is the region that matters most.

Taylor Ice Dome shows +/- 2 °C temperature variation. There is no correlation between temperature and CO2 level.

Temperature Reconstruction from Chile. ( von Gunten, 2009)

Moberg 2005 Reconstruction (that includes tree rings) shows warmer climate 1,000 years ago and cooler climate between.

20 year average of the same Moberg chart.

From The New Scientist. Shows MWP almost as warm, but not quite as warm as today.

(Black) Actual Global Temperature (Purple) Temperature Anomaly since 1979.

Tropical temperature anomaly and the ENSO.

UAH satellite anomaly for each hemisphere for the period around the eruption. Such an event had an obvious impact on the Earth's temperature for years after the eruption.

The AMO over the past 1,000 years. The average, upper limit and lower limit are all trending down for the past 1,000 years.

The circled section in November is an Indian Summer. The temperature prior to that had been freezing during the night. Then the temperature increased to day time highs well over 20 °C and lows ~10 °C. That warming up against the natural trend meant little a month later when high temperatures were below 0 °C.

The NH gets a +/- 8 °C range. The temperature anomaly for that range is miniscule, but it is the NH anomaly that drives the global temperature anomaly in most years.

The NH gets a +/- 8 °C range. The temperature anomaly for that range is miniscule, but it is the NH anomaly that drives the global temperature anomaly in most years.