Solar activity is certainly a key factor in climate warming. Solar radiation is the only heat source we have that has the capability to add heat effectively to our entire ecosphere. And Solar activity is the main factor in beating back the galactic influence to the level of the
Heliosphere
We are further protected from outside (galactic) influences and local solar influences by our own magnetic field.
Despite all this protection, some high energy rays still penetrate our atmosphere and have an affect on the climate. This type of climate forcing does follow a cycle.
There are two cycles that act both independently and combined. Solar irradiance fluctuations correlate well with sunspot activity, following both 11 year and 22 year solar cycles. During the 11 year cycle where the suns magnetic north points in the same direction as earths magnetic north, the solar influence is greater. So solar input will be increased during that phase of sunspot activity. As solar (sunspot) activity decreases, so does the suns input of solar radiation to the ecosystem. But the variance is only marginal. During the next 11 year cycle, when the poles flip and the suns south pole is aligned with the earths north pole, solar influence is lessened. Sunspot activity increases, but to a slightly lesser degree than the previous 11 year cycle, and the earth warms again, though the solar forcing component is lessened during the latter half of the 22 year cycle.
Solar input is only half of the climate equation though…
(since the Maunder Minimum through 2000 solar irradiance has fluctuated by only .0022%
http://www.junkscience.com/Greenhouse/irradiance.gif from between 1363.5 Wm-2 and 1366.5 Wm-2 or a difference of 3 Wm-2)
The other side of the equation involves solar absorption and infrared reflectance.
What has been referred to as Greenhouse Gases:
water vapor, which contributes 36–72%
carbon dioxide, which contributes 9–26%
methane, which contributes 4–9%
ozone, which contributes 3–7%
Also
Nitrous oxide and
Chlorofluorocarbons
Increasing these gasses act to increase IR absorption & retention in the atmosphere thereby creating a gradual heat overbalance in the equation.
This chart indicates that hard winter conditions are ending earlier in this particular region. With first melt happening, mainly due to increasing warmth, as much as 30 days earlier than in 1920.
Similar things are happening around Greenland with earlier than normal spring warming happening right now.
The Climate was relatively stable from 1800 to 1900. There is a discernible rise in temperature around 1910 which can be linked to the introduction of the automobile and Ford Motor Companies Mass Production concept and the Model T of 1908. By 1912 there were 7000 ford dealerships selling cars to average families. Cars were no longer toys of the wealthy. Climate then shows more ups and downs with a large decrease in 1940 (about the time that WWII was well in swing and cities were burning adding soot to the atmosphere). Then, in 1960 something happened that upset the balance and temperatures started to rise again. One of the biggest changes in the actions of humans was when Moms went to work, the advent of 2 wage families. This created a new demand, the 2 car garage. Automobile ownership practically doubled as both Mom and Dad were working and driving to and from work.
