Last month we had a look at the Bigger, better, new hockey stick from a study by Marcott et al. Since then Skeptical Science has a post on the phoney skeptical/denialist critique of the study. We now have a new study, Continental-scale temperature variability during the past two millennia, by 78 scientists from 24 nations analyzing climate data from tree rings, pollen, cave formations, ice cores, lake and ocean sediments, and historical records from around the world published in the journal Nature Geoscience. The study found:

There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century.

The real interest was in the regional variations on a continental scale. Temperatures were identified for the Arctic, North America, South America, Europe, Asia, Australasia and the Antarctic. There was insufficient data for Africa. Continue reading Global heating update →