Assessment on Temperature Changes of China During the Past 2000 Years

The Fourth Assessment Report of IPCC(IPCC AR4)concluded that average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than that of any other 50-year period in the last 500 years and likely the highest in at least the past 1300 years.However,after evaluating Global or Northern Hemisphere temperature change series derived from ice cores,tree rings,