The warming of the world during the last century is greater – and more widespread – than any other shift in the global climate in the last 1,200 years, researchers reported Thursday. The analysis of data from tree rings, fossil shells, ice cores and actual temperature measurements from 14 locations on three continents shows that the current warming trend is the most extensive change — warm or cold — since the time of the Vikings. In their report in the current issue of the journal Science, climatologists Timothy Osborn and Keith Briffa of the University of East Anglia, home to...
