World at its warmest of past 1,200 years

The last part of the 20th century is considered by many scientists to be the warmest period since modern record-keeping began around the 1850s, but new research indicates the era is even more remarkable.
The warmth in which the Northern Hemisphere has basked since the middle of the 20th century has been the most widespread and longest period of unusual climate experienced at any time during at least the past 1,200 years, according to a research paper in the journal Science.
The finding, by a pair of climate researchers from the University of East Anglia in Norwich, U.K., was based on comparisons of the current warm period to other hot and cold intervals since the year 800.
Among these long periods of alternating temperatures were the “Little Ice Age” that sent Northern Europe into a deep freeze, and the Medieval Warm Period around 1000, when an interval of more benign climate coincided with the rise of the sea-faring Vikings. : World at its warmest of past 1,200 years, researchers show