Climate and Human Civilization for the Past 4,000 Years

Watts Up With That?

Guest essay by Andy May

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.


Figure 1 (click on the figure to download in full resolution)

Major events in human civilization are noted on the graph. If you download the pdf it prints well on 8.5×11 inch paper. This timeline provides more detail for the last 4,000 years than I could fit on my previous timeline to 18,000 years. The principle reference for the ice core study can be seen here. At the top of the graph the Blytt and Sernander

View original post 1,689 more words

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s