[Phil Jones] I've shown that the borehole data in Europe agree well with the long instrumental data in both the UK and Europe. The biggest differences/problems seem to come with the North American borehole data, which show the 16/17/18th data much cooler than the European/Asian/African data in the 16/17th century. I'm still reminded by the potential effects of land-use changes, principally in the eastern US, which could be making your North American series too cool. I realise you've taken great care with the selection, but this is a nagging doubt and will be picked up by the few skeptics trying to divide us all about the course of change over the last millennium.
Editor’s note–from john1282
24 minutes ago