This goes back to what we knew in the 60s, 70s, and early 80s. But what no one will talk about now.
You have a remarkable Pearson correlation of +0.84. That’s good science, there! And you cannot blame man-made CO2 emissions for the previous 2000+ years.
Another inconvenient truth. Via the Global Warming Policy Forum:
The dominant climate cycles have persisted for a long time: “This allows to predict cooling until 2070 AD.”
In a just published study in The Open Atmospheric Science Journal here, German scientists Horst-Joachim Lüdecke and Carl-Otto Weiss have used a large number of temperature proxies worldwide to construct a global temperature mean over the last 2000 years, dubbed G7, in order to find out more about the sun’s role on climate change.
Their results drop a huge surprise on the laps of scientists who have long believed the earth is warming due to human-emitted CO2.
The analysis by the German scientists shows the strongest climate cycle components as 1000, 460, and 190-year periods. The G7 global temperature extrema coincide with the Roman, Medieval, and present optima, as well as the well-known minimum of AD 1450 during the Little Ice Age.
These cycles are even on Wikipedia. We’ll see how long it’s allowed to remain there (Wikipedia does not allow any questioning of the AGW models).
Correlation 0.84
Using further complex analyses, they constructed a representation of G7, which shows a remarkable Pearson correlation of 0.84 with the 31-year running average of G7.
The authors used extensive local temperature proxy data [2 – 6] together with Britain’s Hadley CRU temperature records since 1870 and the recent satellite measurements, and combined them to make up the global temperature time series G7 for the last 2000 years.