Northern Hemisphere surface air temperature records, which are important for understanding global climate, do not accurately predict future temperature trends, according to a paper published in the July issue of Geophysical Research Letters. James Eisner of Florida State University and Anastasios Tsonis of the University of Wisconsin-Milwaukee applied a new statistical analysis called the “bootstrap method” to data from three Northern Hemisphere long-term temperature records. This was done to determine how accurately the temperature records portray future temperature trends.
Their results show that although these records demonstrate a long-term temperature increase, their corresponding trends over the past 100 years are statistically different. Eisner and Tsonis made their analyses from three records of the Northern Hemisphere's temperature over the past 100 years.