Read here. Despite the recent BEST climate science fiasco, the BEST team has at least confirmed what everyone on the planet agrees to: the globe has warmed since the Little Ice Age; it warmed at an increase rate during the late 20th century; and, global warming disappeared with a subsequent major deceleration during the 21st century. What the BEST researchers did not determine is the cause of the warming - is temperature variation anthropogenic or natural? A new peer reviewed study in a major physics journal provides the answer to that question.
The answer: Yes!
Using advanced statistical techniques, Ludecke et al. concluded that global temperature variation has causes related to both anthropogenic and natural reasons. Depending on a given climate station's temperature measurements, the warming (cooling) trend is likely to be explained, from 40 to 90%, by natural causes. (The remaining anthropogenic causes of temperature change may be a result of greenhouse gases, UHI, land-use, aerosols and etc.)
"We evaluate to what extent the temperature rise in the past 100 years was a trend or a natural fluctuation and analyze 2249 worldwide monthly temperature records from GISS (NASA) with the 100-year period covering 1906-2005 and the two 50-year periods from 1906 to 1955 and 1956 to 2005...The data document a strong urban heat island eff ect (UHI) and a warming with increasing station elevation...About a quarter of all the records for the 100-year period show a fall in temperatures...that the observed temperature records are a combination of long-term correlated records with an additional trend, which is caused for instance by anthropogenic CO2, the UHI or other forcings...As a result, the probabilities that the observed temperature series are natural have values roughly between 40% and 90%, depending on the stations characteristics and the periods considered." [Horst-Joachim Ludecke, Rainer Link, and Friedrich-Karl Ewert 2011: International Journal of Modern Physics C]
Additional BEST and peer-reviewed postings.