The Sun's current sunspot activity ( solar cycle 24) correlates to solar cycle 5, the Dalton Minimum (1790 to 1830)
Sunspots are magnetic storms that vary in number with the strength of the solar electromagnetic field. Variations in the Sun’s electromagnetic field causes a variation in cloud formation in the Earth’s atmosphere from cosmic rays. A stronger field deflects the rays; a weaker field allows them to penetrate deeper into the atmosphere.
Clearly there is some sort of relationship ( coincidental or otherwise) with a solar cycle with a low numbers of sunspots and a climate cooling cycle. Sun spot records start in 1610 .
The earths climate is influenced by
Pacific Oscillation
Atlantic oscillation
Arctic Oscillation
11,500 year Glacial cycle
Ice-albedo feedbackhttp://www.ncdc.noaa.gov/paleo/abrupt/data2.html
The ocean is a massive CO2 sink, it's not CO2, but water’s massive latent heat differential either side of the liquid state + that regulates climate
The wild card in climate predictions is if a large volcanic eruption occurs during a solar sunspot minimum
The 1815 eruption of the volcano Tambora in Indonesia resulted in 1816
"The year with no summer"
End of the Ancient Era 536AD Erupting volcanoes in 536 & 539AD triggered a huge dust cloud which blocked out the Sun for 18 months
It's not global warming we need to worry about, its Ice ball earth
20,000 years ago, more or less, an ice sheet one mile thick lay over what we now call New York City.