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Earth, Environment

Solar Variability Most Likely Not the Cause of Global Warming

21 Feb , 2008 by

The gradual increase in global temperatures is getting harder and harder to pin on the Sun and its energy output variability. The Sun has a variation in how much energy it outputs but this variability is only about one tenth of one percent. The pattern of atmospheric heating since the 1960s is showing an increase with the increase in human activity (industry, transportation, power generation) and neither are showing signs of slowing down…

At the American Association for the Advancement of Science (AAAS) meeting in Boston, many talks are focusing on climate change and the human impact on the Earth. Experts in solar science, climate modeling, and atmospheric science are exploring the issues surrounding what the main culprit behind the rapid rate of change in global temperatures could be. The sole energy input into the Earths atmosphere comes from the Sun; so many scientists have looked toward our star for the answers. The Sun does vary its output of energy (historically, this is obvious during long periods of solar inactivity, such as the Maunder Minimum in the 1600’s where hardly any sunspots were observed on the Sun – this reduction in activity has been linked to the “Little Ice Age” experienced during this time), but generally speaking, the net energy increase or decrease is very small.

The link between solar variability and global warming has taken another blow from analysis of historical samples of sediment containing radioactive carbon-14 and a beryllium isotope. Quantities of carbon-14 and beryllium-10 reflect solar activity as they are greatly affected by solar magnetic field strength. The Sun’s magnetic field is directly related to solar activity (and therefore sunspot population). These radioactive isotopes are created by the impact of cosmic rays in the Earths atmosphere, and should the solar magnetic field be strong (i.e. during periods of high activity), cosmic rays will be blocked, reducing the quantity of isotopes in the sediment.

However, results from this analysis appear inconclusive and no strong link can be found in favour of increased solar activity during periods of atmospheric heating.

Linking any atmospheric phenomenon with solar variability is a difficult task. Attempts to connect monsoons with the 11-year solar cycle for instance have failed in 150 years of trying. It would seem that, for now at least, any connection between increased solar energy output and global warming is tenuous at best.

Casper M. Ammann, climate modeler at the National Center for Atmospheric Research in Boulder, Colorado, points out that global temperatures are rising at a historic rate, and there remains no link between solar variability and global warming. He states that global warming has “nothing to do with changes in solar activity. It’s greenhouse gases. It’s not the sun that is causing this [climate] trend.”

Perhaps the only answer is to drastically cut back our dependence on fossil fuels to slow the rate of carbon dioxide production. Even if the Sun should decide to become inactive, as there appears to be very little relationship between solar output and global warming, we will not be able to escape the greenhouse gases heating up our climate.

Source: Physorg.com

By  
[Follow me on Twitter (@astroengine)] [Check out my space blog: Astroengine.com] [Check out my radio show: Astroengine Live!] Hello! My name is Ian O'Neill and I've been writing for the Universe Today since December 2007. I am a solar physics doctor, but my space interests are wide-ranging. Since becoming a science writer I have been drawn to the more extreme astrophysics concepts (like black hole dynamics), high energy physics (getting excited about the LHC!) and general space colonization efforts. I am also heavily involved with the Mars Homestead project (run by the Mars Foundation), an international organization to advance our settlement concepts on Mars. I also run my own space physics blog: Astroengine.com, be sure to check it out!


30 Responses

  1. Tom says:

    Wait a second here…it was my understanding that there are two issues here.

    First, as described in this article, was a theory that the subtle changes in the sun’s brightness and heat output may have an effect on earth temps. I seem to remember reading something regarding a recent study that found that the sun’s average heat output and changes in it did not have any measurable effect on our atmosphere.

    However, I think it is important to point out that there are two very different factors at work involving the sun.

    What is very important is earth’s orbit, and how our distance from the sun changes over time as the earth’s orbit varies (over many thousands of years). Remember that earth’s orbit around our star moves from a nearly circular orbit into a much more “squished” elliptical orbit. During the years in which earth is in the more elongated elliptical orbits we spend much more time further away from the sun. More distance from the sun equates to longer, colder winters across the globe.

    This means that, over thousands of years, the earth moves through natural cycles of freezes and thaws. Astronomers and other scientists have calculated and agree that the earth’s orbit is currently transitioning into a more circular orbit where we spend much more time closer to the sun. A few thousand years ago, during the most recent ice age, the earth’s orbit was elliptical. Now, more circular orbits mean warmer years, more thawing ice, and (for lack of a better term), global warming.

    However, while we are warming now, the cycle will continue. We know there have been ice ages and subsequent thaws in the past, and we know they will continue into the future.

    Part of our problem as a people is that we still seem to think the earth is in the center of the universe, and that we must be the most important things around. If the planet is getting a little bit warmer right now, well, it must be us, right? Forget that this has happened many times before. Forget that a single large volcanic eruption spews more CO2 and other gasses into the atmosphere that humans could ever hope to generate. Forget that there were ice ages and thawing periods long before evolution had ever considered the human species…and forget that there will continue to be freezes and thaws long after evolution has erased and forgotten all us lowly humans.

    I know…long comment…but I can sum it up quickly. Yes – the sun’s magnitude and heat output have minuscule effects on our atmosphere.

    No – this fact does not exclude the sun as a factor in what is actually causing what we perceive to be ‘irreversible warming’.

  2. Steve says:

    You’ll see a drastic change once the ZENN car is introduced as an actual bonafide vehicle on the streets and not the little Go Kart it is right now.

  3. Fraser Cain says:

    I want a ZENN car. Maybe they’ll give me one of those for review. :-)

  4. Dave says:

    Hummmm, a “scientist” huh? First is says that the results are “inconclusive” which by definition means can’t conclude one way or the other. Followed just two paragraphs later the learned scientist says proudly “There is NO link!” Really . . . . No agenda here is there?

  5. Trippy says:

    People always bring up the Milankovitch cycles.

    One thing I have noticed (repeatedly) is that people who bring up the Milankovich cycles, generaly don’t seem to do the research required to realize that they’re entering a cooling phase.

  6. Bernd Missal says:

    This discussion about solar variability and global warming is probably part of the systematic desinformation effort by the industry.
    It’s a campaign that, up to now, succeded in convincing the public that the climat risc isn’t yet proven.
    But no matter the cause, we got to do something about it, and we could. We even have the money.
    But our social-economic system proves once again to be a dead end.
    Survival of the fittest? May be we are not fit for surviving in our environment.

  7. Joshua brotman says:

    I do think it is hard to pinpoint the what caused the little ice age, but from the sound of it, it wasn’t the sun.

    This does not rule out the fact that it still may influence us.

    Even though the variability of the energy of the sun is only by .1 percent, the earth does not receive more than 1 percent of the total output of the sun. So a little as it may be, it is still likely a great factor even if it is not directly seen by our weather patterns.

  8. Dave says:

    An absence of evidence != evidence of absence.

  9. Laszlo says:

    Yes, the Milankovich cycle’s say we’re in cooling, but remember they’re at least 3 I recall, 200k, 45k & 11k, or there abouts. Hard to acquit sun from lil Ice age. Some huge volcano in East Indies put out enough ash to ‘nuclear winter’ a couple years. Vast famine occurred in Europe due permafrost throughout summer some summers. That may have hastened new world colonization. From the difficult maritime adventures, losing ~half ships or crew, one wonders if the thermohaline (gulfstream) current didn’t demise?
    The orbit comment could be right on, but I’m uncertain @ timeline. Now we’re facing sun-ward from Northern Hem during apogee, while the Southern Hem gets the seasonal extremes (facing sun-ward during perigee & away during apogee. The only thing saving their *** is sea moderation. Guess what, Earth precesses(wobbles) shifting it’s 23 1/2 tilt other way every so many thousands years(Milankovic worked it out). Northern Hem doesn’t have the H2O buffer to handle that, but different theories propose glaciers/Ice age vs real desertification/drought at lower latitudes. Name your poison. Les

  10. Forester says:

    I feel you may have inadvertantly misrepresented the case for Solar influence.

    Here it is, put forcefully, by David Archibald – “Solar Cycle 24: Implications for the United Statesâ€? http://www.warwickhughes.com/agri/Solar_Arch_NY_Mar2_08.pdf

  11. Calvin L. says:

    Bravo, Dave
    Nice comment.

    Anybody here watched ‘An Inconvenient Truth’? It already clearly points out the sun isn’t a factor in global warming. Plus, as Laszio said, the Milankovic cycle cycles every 200,000 years. However, according to ‘An Inconvenient Truth’, the amount of warming we have had in the past 40 years is double the amount shown by ice cores up to 650,000 years old

  12. Paul C. says:

    People who deny increasing global temperatures are ridiculous , BUT, people who think for a second that humanity will end our desire for fossil that come straight out of the ground, ready to use, are just as ridiculous. Our main focus should be on mitigation measures for the inevitable changes. An unfortunate fact of life is that there is NO FORSEEABLE VIABLE ALTERNATIVE TO FOSSIL FUELS.

  13. dbreit says:

    Conveniently forgetting that it was far warming in the early part of this Century…

    This story is nothing but a ruse..

    And a poor one at that..

    One comment said we had the money to “solve this”..

    All the money in the world will not solve this, as man is not the cause of any suspected warming…

    It is all about the Sun and the orbital parameters of the Earth’s orbit.. Just ask the previous Ice Ages that formed and receded in the past…

    And another thing..

    I don’t trust a weather forecast for 48 hours from now.. Why would you trust one 1, 5 , 10 or however many years out in the future these idiots are suggesting.. I can predict that we are warming because there was Glacial Ice in Missouri 16,000 years ago.. So it is warming.. Big deal..

    and yet another point..

    What is the number one Greenhouse gas???
    Water vapor, by a long shot.. Can they model it accurately?? Not a chance..

    Too bad teaching actual science went out the window years ago.. This is such a patently false theory that thinking objective people discounted years ago. But the truth and facts do not currently gather grants now does it..

    Pity..

  14. marcellus says:

    “Evolved societies don’t live long enough to communicate.” “The polar ice cap will disappear within our lifetime.”

    Bah! What rubbish. A lot of these global warming advocates sound like the pot smoking, long haired Grateful Dead “heads” that used to plant trees on some of our crews down south before the Hispanics took over.

    I don’t trust any weather forecast beyond 48 hours either, and by the way, you still have to get up for work in the morning.

  15. Luke Bryant says:

    Can someone explain what caused the great ice ages of the past hundreds of thousands of years – if it was not related to solar variation, what was it !? pollution from coal, oil, or what!?

  16. Fenring says:

    There was climate change aplenty in Earth’s past, caused by many “natural” factors: orbit, inclination, sun power output, evolving life, etc. Difference is in the speed of this process. While significant natural climate changes happend in 1000s of years, the one we’re experiencing now is happening much faster.

    Also, i’d like to point out to anyone who thinks it’s arrogant/egocentric of us to think we might be influencing nature and climate, let’s just start with the fact that at least 1/3 of Earth’s arrable land is today used for farming. That’s growing livestock and plants. This does not include the living space we occupy, nor the area industry takes. And it’s not like there was nothing there in the first place.
    If you could look at Earth at night from POV of a sattelite in a geosynchronus orbit, you’d see plenty of Earth’s surface covered by artificial light.

    GW or not, we humans will survive no matter what, i’m not worried at all. We have technology and that takes us way beyond the survival game.
    To my disgust though, everything else on this planet suffers and will suffer even more by the time we’re done with it. So in my perspective it’s much more arrogant to assume we have no impact and we should just proceed as usual, taking advantage of everything within visual range and beyond.

  17. UkMan says:

    Wouldn’t it be great if the moon was the same size as the earth. It would have an atmosphere, oceans, everything! Then – when we’ve messed up on this planet we could all move in ‘next door’.

    Unfortunately for us – the Earth is all we have. We have nowhere else to go.

    The fact is that – within our lifetime – we could see the total disappearance of the polar ice cap. Some of this ice is over a million years old – it’s been there long enough for polar bears to evolve to live on it.

    The probability that this melt happened by chance within two hundred years of the industrial revolution is too much of a coincidence.

    Perhaps this is why we haven’t heard from ET – Developed societies simply don’t survive long enough to communicate.

  18. Timber says:

    At 45.9N, 122.3W I’m starting to build my greenhouse today :)

  19. UkMan says:

    Marcellus
    If you’re going to quote me – at least make it accurate!

    Be honest – the reason you dispute humans being responsible for GW is that you dont want to stop using your car or change your lifestyle.

    Your comment about Hispanics tells me all I need to know about your right wing views. I personally hope Obama gets in.

    …I’ve never smoked pot and I don’t posses a Gratefull Dead album.

  20. marcellus says:

    Change my lifestyle, UKMan? I’ve planted 1.7 million trees BY HAND since I started back in December 1986, and I’m still planting more trees every year. You couldn’t carry my hoedad, much less pack on a thousand trees and hammer them in deep, straight, and tight.

    The Hispanics can, and I have a lot of respect for the legal ones in our country. The illegal ones? Not so much.

    Keep rootin’ for Obama. He’ll give you change. In fact, it will be all you have left in your pocket.

  21. Tareece says:

    Its amazing that we think we know what is exactly happening to this world , his solar system and this universe when we are, within the realm of galatic time scale, merely new borns.
    First thing we need to acknowledge is the limitations of our knowledge. We didn’t know crap 50 yrs ago about just about everything related to moon travel, we didn’t know jack 30 yrs ago about the effects of long term (a matter of weeks) space exposure until Skylab, and we don’t know jack about what really happened to this earth over its history. Its educated guesses at best.
    Honest people recognize their limitations and to think we can categorically blame this entirely on humans is alarmist and ill-conceived. If memory serves the “Consensus” of scientists believed we were heading for an ice agein the 60’s and 70’s. Could the rapid turnaround of consensus actually be the result of eco-policies put in place in the 70’s and 80’s?
    And if you discount that then how do justify the assumption now of “historic” warming..WTH? what does “historic” mean anyway? Yeah, last yr several “historic” highs were based in the 1930’s….Oh and why did the NASA climatic models get re-worked last yr to show that the hottest yrs were in the ’30’s? Science is as good as its data.
    If the data is faulty, the assumptions and consensus should be discarded as any other mistake. Oh, but this ‘consensus’is now a multi-billion (trillion) industry….yeah, ain’t nothing like “pure” science… The rebel is now the establishment…Sweet irony

  22. Ken B. says:

    I was going to leave a comment but I can’t do any better than dbreit’s comment. I agree completely with his sentiments.

    I will add that GW or climate change or whatever it’s called now is more about a belief system than science. I have a kid in school in grade 4 and they are being indoctrinated in global warming belief system. Kids this age don’t have the science education and background to understand what they are being told.

    Al Gore tells us the science is settled because he doesn’t want people looking for themselves. The Canadian prophet of GW, David Suzuki, is advocating imprisoning politilical leaders who challenge man made global warming.

    Such nonsense.

  23. Cosmos says:

    Everybody who is commneting on the global warming issue from either side should read the article at this link. http://wmbriggs.com:80/blog/category/climatology/

  24. Frank Lansner says:

    Please everybody, read this article:
    http://www.warwickhughes.com/agri/Solar_Arch_NY_Mar2_08.pdf

    Its, intelligent, relevant and very carefully made. I have read many scientific articles in my life, but this one is outstanding.

    K.R. Frank

  25. Tony Trenton` says:

    The butterfly effect & chaos are real but indefinable. So looking for “The Reason” is not reasonable.

    What is interesting, is the nature of the comments.
    Our intellect is only capable of conceiving thing in 2d. Either, or. This or that.
    When multiple factors greater than 2 are interwoven & chaos ensues. It is not yet possible to make predictions & may never be.
    But it is fun to speculate.

  26. Fenring says:

    I don’t understand what is this multi-gazillion dollar consensus that will rob us of our well earned money by spreadig false alarm about GW?

    How much money do you pay to combat the alleged GW? I know I pay zero.

    This part just doesn’t make any sense to me at all. What is this GW conspiracy that everyone speaks of and who stands to profit from it? By what means? How does it compare to the profit of the oil companies and industry?

  27. Dark Gnat says:

    Let’s see…

    Climate change believers would gain: Cleaner air, less economic dependence from hostile nations, keeping our food supplies available, keeping air-producing rain forests available.

    Climate change detractors would gain: Continued economic dependence on hostile nations for oil (leading to more wars), automobile manufactures, and more profits to add to the billions already made by fossil fuel companies.

    Who is in the position to gain the most from the two sides? Big Businesses, and the governments they buy.

    I just don’t see what the climate change advocates have to gain. I see no real reason for a “conspiracyâ€? to convince everyone to change their lifestyles.

    Are we going to also pretend that deforestation isn’t happening, that smog doesn’t exist, or that the ozone layer isn’t deteriorating?

    Sure, natural events may be contributing to climate change, but man-made pollution must have an affect as well. It may be simply escalating the changes, but it is an indisputable fact that we have changed the world.

    If these changes are as rapid as so many reputable scientific associations say, then we need to do something. If we could just slow the climate changes back down to their natural levels, then fine.

    If we err, would it not be far better to err on the side of caution?

  28. Paul F. Dietz says:

    Wow, the faith-based delusions from the GW denialists sure is thick in this set of comments. Contrary to the nonsense you’ve filled your heads with, GW from anthropogenic gases is solidly based on physics and observational evidence. The contrary position is increasingly resembling other paranoid fringe pseudoscientific cults, like UFOs, ESP, creationism, and CFC/ozone hole denialism..

  29. Dan Tillmanns says:

    Just wait until the Yellowstone volcano lets go.

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