Global Warming and the Sun

It is obvious that our sun is the primary driving force behind Earth's climate. It can't be anything but since it is the source of 100% of the heat that is necessary to sustain life on the planet. But, is the sun a strong player in the current climate change (we've already noted that Earth's Climate is constantly changing)? Lets take a look at the evidence.

One of the ways historically judging solar output is by counting sunspots. Sunspots have been counted since the early 17^th century and closely monitored since c. 1749. We have nearly 400 years of accurate observations to work with here, and from this record we know that sunspots vary from maxima to minima over an approximate 11 year cycle.

In the 17^th century, there were very few sunspots recorded - extraordinarily few. This period of solar (in)activity is known as the Maunder Minimum. This period of lessened solar activity corresponds to the onset of the colder climate period known as the Little Ice Age, and is illustrative of the fact that Earth's climate does indeed change over time. The exact cause, or causes of the Little Ice Age are not well understood, but solar output or the lack thereof definitely played a part.

We have just gone through an unusually prolonged sunspot drought. "The number of sunspots can change from cycle to cycle, and 2008 saw the longest and weakest solar minimum since scientists have been monitoring the sun with space-based instruments, " Science Daily, 06/14/2011.This may very well explain the global cooling that has been experienced in the early 21^st century.

Sunspots are now returning as usual but they are not coming back as strong as they have in the past. "The current prediction for Sunspot Cycle 24 gives a smoothed sunspot number maximum of about 96 in February of 2013. ... The current predicted size still makes this the smallest sunspot cycle in over 80 years", Marshall Space Flight Center.

So we know that solar activity was, at least, a contributing factor to the Little Ice Age, and we have a plausible link between solar activity and the current cooler climate. We also know that the current sunspot cycle is likely to be one of the least active in recent years. This provides us with a perfect opportunity to test the relationship between solar activity, as evidenced by sunspots, and Earth's climate. Not only will we gain a better appreciation for the solar effect on climate, we will also understand the relative potency of atmospheric CO₂ in tegard to climate change.

“If we have a solar minimum and global temperatures continue to climb over the next decade, it will have established carbon dioxide as a potent force on the Earth’s climate. It’s going to be a very good scientific test of carbon’s real effect.” -- Dr. Robert Baker, University of New England, North Queensland Register.

When you get right down to it, the sun continues to surprise us. The more we look at it the more new things we find. Here's a short list of recent findings:

• Solar Cycle Driven By More Than Sunspots (09/17/2009)
• A Puzzling Collapse of Earth's Upper Atmosphere (07/15/2010)
• Global Eruption Rocks the Sun (12/13/2010)
• Solar Mystery of Missing Sunspots Explained (03/02/2011)

• New Insights On How Solar Minimums Affect Earth (07/14/2011)

With new information coming in all the time, it is obvious that we still have much to learn about the sun itself. It is premature to totally discount the sun and its effect on climate change. It is hubris to think we know enough about the sun to say that it has only a small effect on Earth's climate.