More data for progressives who cry for scientific truth.
The Holocene Thermal Optimum ended at different times in different parts of the world, but it had ended everywhere by 4,000 BP (BP here means the number of years before 2000) and the world began to cool. The timeline shown in Figure 1 shows the GISP2 Central Greenland ice core temperature proxies in blue and the HadCRUT 4.4 surface temperature estimates for the same area in red.
