Professor Dr. Jan Esper and his team at JGU used tree-ring density measurements from pine trees which have not been totally fossilized to produce a climate reconstruction reaching back to 138 BCE. The research precisely demonstrates things haven't been getting hotter, in fact the trend over the past two millennia has been towards a big chill.
"We found that previous estimates of historical temperatures during the Roman era and the Middle Ages were too low," says Esper. "Such findings are also significant with regard to climate policy, as they will influence the way today's climate changes are seen in context of historical warm periods." The new study has been published in the journal Nature Climate Change.
The international research team used these density measurements from sub-fossil pine trees in northern Scandinavia to create a sequence reaching back to 138 BC. The density measurements correlate closely with the summer temperatures in this area on the edge of the Nordic taiga; the researchers were thus able to create a temperature reconstruction of unprecedented quality. The reconstruction provides a high-resolution representation of temperature patterns in the Roman and Medieval Warm periods, but also shows the cold phases that occurred during the Migration Period and the later Little Ice Age.Why haven't previous tree ring studies displayed similar results? We know that the data used by Dr. Mann to created the famous hockey-stick graph was flawed. He chose the trees which would give him the desired results--- a chart that looked like the one below reflecting consistent temperatures until the industrial revolution then...heat stroke. To get his results among other thing, Mann covered up the Medieval warming period (the "dark ages" were also the hot ages) when temperatures were hotter than they are today.
In addition to the cold and warm phases, the new climate curve also exhibits a phenomenon that was not expected in this form. For the first time, researchers have now been able to use the data derived from tree-rings to precisely calculate a much longer-term cooling trend that has been playing out over the past 2,000 years. Their findings demonstrate that this trend involves a cooling of -0.3°C per millennium due to gradual changes to the position of the sun and an increase in the distance between the Earth and the sun.
"This figure we calculated may not seem particularly significant," says Esper, "however, it is also not negligible when compared to global warming, which up to now has been less than 1°C. Our results suggest that the large-scale climate reconstruction shown by the Intergovernmental Panel on Climate Change (IPCC) likely underestimate this long-term cooling trend over the past few millennia."
At the time of it's release scientists that questioned the Mann hocky-stick chart for the way the tree ring data was derived, but that didn't stop the global warming hoaxers from promoting it as having almost divine origins.
Dr. Jan Esper and his team at JGU seem to have added to the voluminous amount of evidence indicating that the global warming/climate change theory is nothing more than a hoax perpetuated by progressives whose real goal is worldwide re-distribution of income.