Sunspot Cycle Length vs Temperature Anomaly │ Jasper Kirkby

The sunspot cycle length as a measure of the Sun's activity:
Variation during the period 1861 - 1989 of the sunspot cycle length (solid curve)
and the temperature anomaly of the Northern Hemisphere (dashed curve).
The temperature data from the IPCC.

Jasper Kirkby (1998) - The sunspot cycle length averages 11 years but has varied from 7 to 17 years, with shorter cycle lengths corresponding to a more magnetically-active Sun. A remarkably close agreement was found between the sunspot cycle length and the change in land temperature of the Northern Hemisphere in the period between 1861 and 1989 [update HERE]. The land temperature of the Northern Hemisphere was used to avoid the lag by several years of air temperatures over the oceans, due to their large heat capacity. This figure covers the period during which greenhouse gas emissions are presumed to have caused a global warming of about 0.6°C. Two features are of particular note: firstly the dip between 1945 and 1970, which cannot be explained by the steadily rising greenhouse gas emissions but seems well-matched to a decrease in the Sun's activity, and secondly the close correspondence between the two curves over this entire period, which would seem to leave little room for an additional greenhouse gas effect.

[...] The observation that warm weather seems to coincide with high sunspot counts and cool weather with low sunspot counts was made as long ago as two hundred years by the astronomer William Herschel who noticed that the price of wheat in England was lower when there were many sunspots, and higher when there were few. See also HERE  

Data: SILSO Royal Observatory of Belgium.

405 Year Sunspot Record Revised and Newly Calibrated

Credits: SILSO Data - Royal Observatory of Belgium, Brussels

Dating back to Galileo and the invention of the telescope, the 405-year solar sunspot record is the longest continuously monitored daily measurement in all of science. Studies into sunspots, solar and planetary cycles corresponding with trade cycles, crop prices and shifts in the markets have accelerated since the 19th century. Now, on July 1st, 2015 the official sunspot record underwent a complete overhaul for the first time since it was created by Swiss astronomer Rudolf Wolf in 1849. The newly calibrated record is likely to have implications in many diverse scientific disciplines including financial astrology.

Yet, this important change to one of science’s most fundamental measurements went literally unnoticed (HERE & HERE) Two sunspot record time series were recalibrated: The first is the traditional International Sunspot Number (ISN) record most people are familiar with. The second is the more physically meaningful group number. Groups have always been counted as part of the ISN. The newly released group number update redefines and corrects defects in the original 1998 version. The newly rebuilt group number time series shows that solar activity is considerably more ‘even’ over its 405-year history than previously thought. Formerly, it looked as though sunspot activity in the past was much weaker than at present, especially prior to 1890. Counting inconsistencies artificially created that non-existent effect. The rebuilt record contains four distinctive dips in solar activity that occur roughly every 100 years.