Climate Change - The last 1,000 years of global temperatures

Average global temperature is now higher than it has been for a long time.


Graph by Klaus Bitterman.

Green dots show the 30-year average of the PAGES 2k reconstruction. 

The red curve shows the global mean temperature, based on HadCRUT4 data from 1850 onwards. 

In blue is the original "hockey stick" from a paper by Mann, Bradley and Hughes (1999) with its uncertainty range (light blue). 

The green dots are calculated using data from many places around the world, using information from a range of temperature proxies, such as documents, ice, lakes, pollen, tree rings, corals, seabeds and speleothems.
78 researchers from 24 countries, together with many other colleagues, worked for seven years in the "PAGES 2k" Project on this climate reconstruction. 

Their study is based on 511 climate archives from around the world.

PAGES is the Past Global Changes programme launched in 1991. 

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