GreehouseTruth Blog :: Sun's Sizzle on Global Warming
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Sun's Sizzle on Global Warming
Conflicting views on Sun's part in climate change
Posted September 15, 2006 by Nathan Cool
We do indeed live in a world where human nature tends to point a solitary finger at crisis causality. We find "a" criminal guilty of murder, or "a" regime to be an axis of evil. But when it comes to global warming, there are indeed many factors to consider. While greenhouse gases have--understandably--taken stage front and center, our world and the elements in the universe responsible for life on it, are dynamic and constantly changing. One of those components, our Sun, is the single most important aspect of warmth on our world--the second most crucial being the greenhouse gases that trap in its heat. Yet as attention has been so graciously given to the second ingredient in the global warming recipe (greenhouse gases), the most salient piece of the puzzle is often overlooked: our Sun, which could be sending us more heat than we'd prefer. We know that the Sun has been responsible for ice ages and warm spells in the past, and global warming skeptics have fervently used the fire in the sky as fodder to bolster their disbelief. A recent study published just days ago though seems to refute this, but once again, we are left with not only answer A or B, but instead C: there's truth coming in from both sides of the climate change battlefield.
The newly published study concerning this latest round of back and forth between doubters and disciples is an article that appeared in the journal Nature on September 14, 2006. (Click here for the study's abstract.) In this study, the lead author, Peter Foukal--a solar physicist at Heliophysics Inc., a small private research firm based in Nahant, Massachusetts--looked at variations in Sun activity since 1978. His team scanned historical records of sunspots, examined radioisotopes from ice cores and Earth's atmosphere, and then crunched this data through climate models to see what these statistics about our Sun would (excuse the expression) bring to light. This team of scientists concluded, relying mostly on their collection of proxy data, that over the past 1,000 years, the Sun's energy barely budged at all, and could not be responsible for the warming recorded during the 20th century. But not everyone agrees on this theory.
In chapter 4 of Is it Hot in Here?--The simple truth about global warming, I dedicated a section titled Once Around the Sun. In this chapter, I discuss the ins and outs of solar radiation fluctuations from sunspots as well as how Earth's receipt of the Sun's heat changes from the varying orbit of the Earth in relation to the Sun. We do know that our orbit around the Sun varies with predictability, thus explaining quite well the periods of ice ages from long ago. This is a no-brainer in the scientific community, and well accepted as an attribution to climate change. These orbital cycles though are not sudden, and we're not in the midst of one at the moment either. But, the variation in solar output--how much energy the Sun shines at us at any on given period--is the big, $65,000 question.
In Once Around the Sun I mentioned how other scientists argue that the short-lived Medieval Warm Period from the 10th to 14th centuries and the Little Ice Age that followed it, were directly related to solar radiation output fluctuations from sunspots. It seems reasonable, since it would be hard to explain just exactly what caused these few-hundred-year cycles of warmth to cold. The believers in the bunch point out that these epochs did not affect the entire planet, and thus, did not represent a global climate warming or cooling. Still, these periods of unreasonable warmth and cold are hard to explain away.
One thing we do know--and that the recent study's researchers agree with--is that the Sun's brightness has most definitely increased in the past 400 years. We know that the Sun is dynamic and ever changing. One day in fact, our beloved Sun will get really, really, really hot, and then go super-nova on us before imploding into a black hole in space. But that's a long ways away, so no need to lose any sleep over that tonight. Still, that bright golden orb in the sky is a disturbed mass of flaming hydrogen and helium--over which, we have no control. We also know that the latest sunspot cycle peaked around the year 2000, which could have given Earth a minor burst of heat, and that the Little Ice Age ended right around the time global temperatures started to increase: at the dawn of the Industrial Revolution.
Circumstantial evidence from the recent Sun study, derived primarily from re-crunching numbers, has seemingly weakened the skeptics' view that solar output fluctuations are contributing to global warming. Yet the jury is still out on this topic, similar to so many aspects of global warming research. But this didn't stop the media from publishing a plethora of slanted stories with headlines like Sun Not to Blame for Global Warming by ABC News, or Study acquits sun of climate change, blames humans by Reuters, among others. And as can be expected, the spin-doctors who formulated these eye-catching headlines failed to tell the whole truth and nothing but.
All too often, the media leave out important details when covering climate change--things like uncertainties or the opposing views. In fact, something left out of most articles covering this latest Sun disputing story was that the study's authors admitted that many other subtle influences on climate from cosmic rays or the Sun's ultraviolet radiation cannot be excluded, and that, moreover, these influences cannot be confirmed. Why you might ask? Well, because they admit that today's models are still too poorly developed to analyze these things--proof once again that we know less about the science of global warming than some may lead us to believe.
Can the Sun be blamed for global warming, or are greenhouse gases the culprit? It's really not a yes-or-no type of answer. It's not just one or the other. It's both. Once again, we need to take a little from column A and a little from column B. Mix them together and you have the whole story. Leave it up to the mainstream media and we're left with unhealthy debates and the continued, never-ending polarization of perspectives on a very serious issue.
More information on the sunspots, solar cycles, uncertainties of climate change and other topics discussed in this blog can be found in my new book, Is it Hot in Here?--The simple truth about global warming. Click here to get your copy.
