New research continues to break Michael Mann's discredited hockey stick - individual proxy studies invalidate Mann's claims
Michael Mann concocted the infamous hockey stick temperature chart in an attempt to overturn known, well established paleo-temperature history. His research was soon after discredited by expert statisticians when it was found that Mann had over-weighted a single American tree some 390 times in order to produce his desired result.
The hockey stick was so thoroughly discredited that the IPCC had to quit using it in their PR "science" literature.
Read here. Most individual climate proxy studies are unable to reconstruct a temperature series that resembles the infamous Mann research. The newest study unable to do so is the Liu et al peer-reviewed research.
(click on image to enlarge)
As the 2,485 year old tree ring chart depicts, modern warming is well within the natural variability that the Tibet Plateau has experienced. As with so many independent studies, the hockey stick statistical fabrication is non-repeatable - it solely exists in the bowels of the Climategate conspirators and their bizarre methodologies.
"A blockbuster Chinese study of Tibetan tree rings by Liu et al 2011 shows, with detail, that the modern era is a dog-standard normal climate when compared to the last 2,500 years. The temperature, the rate of change — it’s all been seen before. Nothing about the current period is “abnormal”...these climate cycles have nothing to with human civilization. Their team finds natural cycles of many different lengths are at work: 2-3 years, 100 years, 199 years, 800 years, and 1,324 years. The cold periods are associated with sunspot cycles...The results showed that extreme climatic events on the Plateau, such as the Medieval Warm Period, Little Ice Age and 20th Century Warming appeared synchronously with those in other places worldwide. The largest amplitude and rate of temperature change occurred during the Eastern Jin Event (343–425 AD), and not in the late 20th century..." [Yu Liu, QiuFang Cai, HuiMing Song, ZhiSheng An, Hans W. Linderholm 2011: Chinese Science Bulletin]