Paper finds solar activity explains complex features of climate change on decadal timescales

The Global Warming Policy Foundation has pointed to a paper published by the International Astronomical Union in 2010 which corroborates Svensmark's solar/cosmic ray theory of climate and concludes,

"The mechanism of the influence of cosmic rays on the cloud formation is not fully
understood, however, our proxy based analyses of cosmic rays and climate change during
the Maunder Minimum exhibit the importance of cosmic rays as a medium of solar forcing of climate change at decadal to multi-decadal time scales. The complex features of solar magnetic and cosmic ray cycles, such as the variable length of the “11-year” cycle, the subsequent lengthening/shortening of the “22-year” Hale cycle, the amplification of the 22-year cycle in cosmic rays at grand solar minima, may be able to explain some of the complex features of climate change at this time scale."

"We have also found that climate proxy record shows cyclic variations similar to stretching/shortening Schwabe/Hale solar cycles in time, suggesting that both Schwabe and Hale solar cycles are playing important role in climate change. In this paper, we review the nature of Schwabe and Hale cycles of solar activity and cosmic-ray flux during the Maunder Minimum and their possible influence on climate change. We suggest that the Hale cycle of cosmic rays are amplified during the grand solar minima and thus the influence of cosmic rays on climate change is prominently recognizable during such periods."

One of many observational examples supporting the solar/cosmic ray theory of climate

Climate propaganda sites such as "Skeptical Science" repeatedly mislead their readers into thinking there is no observational evidence in the scientific literature for the solar/cosmic ray theory of climate, and mislead them into thinking that this theory alone is the only solar amplification mechanism described in the literature, but it is in fact only one of many such published mechanisms. Skeptical "Science" also misleads its readers by claiming the Sun has nothing to do with global warming or climate change by falsely claiming solar activity has decreased since the 1960's. This is false because the Sun was in a Grand Solar Maximum, at the highest levels of the past 3,000-9,800 years in the latter 20th century, as clearly demonstrated by the sunspot integral of accumulated solar energy, which peaked at the end of the 20th century right along with global temperatures:

It's the Sun

The Maunder Minimum 1645-1715 AD of solar activity corresponds to the tree ring cosmogenic isotope carbon-14 in the next graph below, which increases due to more cosmic rays at times of low solar activity.

Full paper:

Influence of solar cycles on climate change during the Maunder Minimum

Abstract. We have examined the variation of carbon-14 content in annual tree rings, and investigated the transitions of the characteristics of the Schwabe/Hale (11-year/22-year) solar and cosmic-ray cycles during the last 1200 years, focusing mainly on the Maunder and Spoerer minima and the early Medieval Maximum Period. It has been revealed that the mean length of the Schwabe/Hale cycles changes associated with the centennial-scale variation of solar activity level. The mean length of Schwabe cycle had been ∼14 years during the Maunder Minimum, while it was ∼9 years during the early Medieval Maximum Period. We have also found that climate proxy record shows cyclic variations similar to stretching/shortening Schwabe/Hale solar cycles in time, suggesting that both Schwabe and Hale solar cycles are playing important role in climate change. In this paper, we review the nature of Schwabe and Hale cycles of solar activity and cosmic-ray flux during the Maunder Minimum and their possible influence on climate change. We suggest that the Hale cycle of cosmic rays are amplified during the grand solar minima and thus the influence of cosmic rays on climate change is prominently recognizable during such periods.