Notice of RetractionAbrupt climate changes in North China and North Hemisphere

Notice of Retraction

After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE´s Publication Principles.

We hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this paper.

The presenting author of this paper has the option to appeal this decision by contacting TPII@ieee.org.

BG algorithm and filtering method is applied to the high- and low-frequency sequences of the northern hemispheric tree ring width and the Beijng Shihua cave stalagmite lamina thickness sequence. The large- and small-scale abrupt climate change (ACC) points are observed. The abrupt change density (ACD) is defined, and the relation between local (North China) and global climate changes is investigated by comparing the distributive characters of ACD in the high-frequency sequence. Results show that climate changes in North China might be consistent with the background of global climate change; The worldwide little ice age might start at the beginning of 13th century, stopped at the end of 19th century, 16th century was the prime period, while the little ice age in China at about the middle of 13th century and stopped at the end of 19th century.