Thursday, June 10, 2010

Was There No Little Ice Age?

Morgan Kelly and Cormac O Grada have a new working paper titled: The Economic Impact of the Little Ice Age. But their main point seems to be that there wasn't much of a Little Ice Age at all. Rather there were some years with particularly bad weather in the middle of the last millennium. If temperatures are smoothed using moving averages these bad years will reduce the temperature of extensive periods of time. There is evidence they believe that there were periods of higher temperature volatility. Winter temperatures in NW Europe began to climb in the later 19th century representing the onset of anthropogenic global warming.

The Little Ice Age is already seen today as not having been as signficant a cooling as once thought, just as the "Medieval Warm Period" is not seen as having been as warm as once thought. I'm not totally convinced by this paper that there was really no such event at all. But it is certainly an interesting study.


  1. More on this by Kelly and O Grada at:

  2. Your readers might also be interested in 'Debating the Little Ice Age' by Kelly and O Grada, available at: