A Few Things Ill Considered

A layman's take on the science of Global Warming featuring a guide on How to Talk to a Climate Sceptic.

Wednesday, April 12, 2006

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It's the Sun, Stupid

(Part of the How to Talk to a Climate Sceptic guide)

This article has moved to ScienceBlogs

It has also been updated and this page is still here only to preserve the original comment thread. Please visit A Few Things Ill Considered there. You may also like to view Painting With Water, Coby Beck's original fine art photography.

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48 Comments:

  • At April 13, 2006 12:03 PM, Anonymous Anonymous said…

    Coby: Interesting post, so does that mean that Wilson's interpertation is not longer considered as an accurate representation?

    I printed off the graph of Total Solar Irradiance Data and it looks like the trough in 86 is almost identical to the trough in 96. The interesting thing is that it looks like the current trough will be lower than the previous two. Humm, this might be a return to ice age conditions ... now where did I put my Newsweek!!

    John Cross

     
  • At April 13, 2006 12:27 PM, Blogger coby said…

    Heh, invest in goose down! AFAIK, they are getting a handle on monitoring solar radiation and understanding its differing effects, but prediction seems nowhere in sight. No one seems to expect very significant changes though. (Wilson's interpretation??)

    The RC articles have more detail than I have tried to stomach so far, but I understand that total solar irradiance is not the whole picture as variations in the proportions of energy at differing wave lengths also impacts many aspects of climate.

     
  • At April 13, 2006 5:58 PM, Anonymous Anonymous said…

    Hi Coby,
    I have a question I'd like you to address. What about the claim that the U.S. is a net sink for CO2 (and therefore it doesn't matter how much CO2 we emit, and the rest of the world should be grateful, etc)?

    Thanks,

    Anne

     
  • At April 13, 2006 7:54 PM, Blogger coby said…

    Hi Anne,

    I guess I'd ask to see some reference to support a claim like that, it strikes me as a bit ludicrous. The US emits aproximately 25% of all the world's anthropogenic CO2, where is it supposed to be going?

     
  • At April 14, 2006 3:03 AM, Blogger Wag the Dog said…

    The US emits aproximately 25% of all the world's anthropogenic CO2, where is it supposed to be going?

    Into the trees and peat bogs. You can read the context of the claim that the US is a net carbon sink in a report released by the US Department of Energy. The term "net carbon sink" needs to be clarified -- all this means is that the North American forests are absorbing more carbon through photosynthesised growth than they are releasing through decay and night-time respiration. The report itself reveals that in the years 1952-1992 growth in forests are estimated to have absorbed 25% of US carbon emissions over the same period. For the rest of the world to be grateful, American biomass will need to absorb well over 100% of anthropogenic CO2 emissions. I doubt very much that the economic growth in the US since 1992 has been outpaced by forest growth to the degree necessary for this to have happened. The report doesn't even project this: 178 million tonnes per year after 1992 vs. 281 million tonnes before 1992. The forests are absorbing less carbon now than they did fifty years ago.

     
  • At April 14, 2006 7:03 PM, Blogger coby said…

    Hi Peter,

    I could only find an abstract for that paper. But given it is over 15 years old and we don't seem to hear much about that hypothesis, I wold take it that it has not taken hold too well...

     
  • At April 14, 2006 7:05 PM, Blogger coby said…

    Thanks for the references wag, I will write an article for Anne's question and take your word for numbers and dates, I don't have time to research that too much.

     
  • At April 14, 2006 7:47 PM, Blogger coby said…

    Hi Anne,

    Have a look at this post.

    HTH.

     
  • At April 15, 2006 8:08 AM, Anonymous Anonymous said…

    Coby,
    Thanks for answering so quickly. I don't remember where I read that claim about the U.S. being a net carbon sink; it was some article picked up by a Google alert. It struck me as particularly bizarre because the author was claiming that it was actually undeveloped, deforested countries like Haiti that were most to blame for high levels of CO2. Ignorance and arrogance are an ugly mixture...

    Thanks for all you do to maintain this site--it's a terrific resouce.

    Anne

     
  • At April 19, 2006 5:46 AM, Anonymous Anonymous said…

    Hi Coby - sorry, it's a busy time for me ;-) .

    In regards to my Wilson comment, that was a reference to Secular total solar irradiance trend during solar cycles 21–23. in Geophysical Research Letters by Wilson. there was some confusion about how to match up the readings of the early satellites and depending on how you did it you could get a small increase or essentially no change. A good overview of the topic is found here:

    http://earthobservatory.nasa.gov/Study/VariableSun/

    John Cross

     
  • At June 23, 2006 8:46 AM, Anonymous Anonymous said…

    I know this is an old thread but I thought that I shoudl address the question of the paper by Eigel Friis-Christensen and Knud Lassen (an of course the initial follow up by Henrick Svensmark). This is an area of much active research and debate still, not a dead dog. The possibility of cosmic ray-aerosol influence on cloud cover is still very much viable and papers ar still being written for and against by several respected scientists.
    Similarly there are other mechanisms being considered such as planetary wave transport.

    Also with regard to the solar 'constant' although in total it varies by little more than 0.1% there was some speculation that small changes in the harder end of the spectrum could be a problem. I freely admit that I have no link for this though.

    Basically I would not dismiss the sun as a factor. I think it is actually a large factor in climate change. However, in my opinion, it is not the dominant factor and the upward trend that has been observed was running hand in hand with anthropogenic effects which could easily tip the scales (and I think they have) from the normal cyclic changes that the sun produces.

     
  • At June 23, 2006 10:52 AM, Blogger coby said…

    Thanks for that comment Andrew. I agree there is alot of legitimate research going on in this area, but as far as I understand it, the cosmic ray effects and similar ideas are quite speculative.

    The sun does seem to have had an influence on 20th century climate trends, but as you describe not a dominant one. This is the notion I am really trying to debunk.

    Cheers,

     
  • At November 06, 2006 3:22 PM, Anonymous Anonymous said…

    There is definitely some strong evidence that the solar output is, in fact, significantly higher now than before..

    Now, Dr. Solanki says that it isn't the core cause of Global Warming, because the Model says that solar output is only 30% of the cause of Global Warming. But he's not a climate scientist - he's just (reasonably) assuming that the GW mathematic Model is true.

    But Hansen's '88 Model (Scenario A, the one that most accurately fits with what happened over the last 20 years) predicted 3x as much warming as actually happened, and, of course, included no assumption of increased solar output.

    So the skeptic would ask - since the Model seems to overestimate, and the Sun is outputing more energy than we assumed, is it possible that the Model is wrong? Maybe the Sun is a far larger contributor to the world's warming than previously thought?

     
  • At November 06, 2006 6:12 PM, Blogger coby said…

    There is definitely some strong evidence that the solar output is, in fact, significantly higher now than before

    The timeframe is a bit too important for you to gloss over there, jb. It is higher "than before" but there has been no trend over the last half of the 20th century, during which time the warming was greatest.

    Now, Dr. Solanki says that it isn't the core cause of Global Warming, because the Model says that solar output is only 30% of the cause of Global Warming. But he's not a climate scientist - he's just (reasonably) assuming that the GW mathematic Model is true.

    Please, it is not complicated to calculate the forcing in W/m^2 from measurements of solar fluxes. Regardless, you are completely wrong that Solanki just assumed anything, he made measurements and did calculations.

    But Hansen's '88 Model (Scenario A, the one that most accurately fits with what happened over the last 20 years) predicted 3x as much warming as actually happened, and, of course, included no assumption of increased solar output.

    Sorry, wrong again. Who told you this? You should look at the papers in question and compare them to the GHG levels these last decades. Here is someone who has done that for you:
    http://rabett.blogspot.com/2006/06/business-as-usual-in-1988-more-silly.html and links therein.

    So the skeptic would ask - since the Model seems to overestimate, and the Sun is outputing more energy than we assumed, is it possible that the Model is wrong? Maybe the Sun is a far larger contributor to the world's warming than previously thought?

    They don't - it isn't - models are always wrong, though some are very useful - it's not.

     
  • At November 09, 2006 8:25 PM, Blogger coby said…

    The only solar cycle are the 11 year and 22 year ones. For those the variance in irradiance is very small and the cycle too short to show up in climate trends.

    I think the irradiance is being measured from a Lagrange point orbit.

    There is no overall trend in the late 20th century.

     
  • At November 15, 2006 8:13 PM, Anonymous Anonymous said…

    "According to PMOD at the World Radiation Center there has been no increase in solar irradiance since at least 1978 when satellite observations began. This means that for the last thirty years, while the temperature has been rising fastest, the sun has shown no trend."

    there was a coronal mass ejection from the sun in 1998 which at the time was the largest ever witnessed by man. wasn't 1998 the warmest year on record according to global warming community? According to the solar and heliosphere observatory at the goddard space center, a 0.6 to 0.7 degree celcius change was recorded.

    Rich L.

     
  • At November 15, 2006 10:20 PM, Blogger coby said…

    I have never heard of any possible link between a single CME and a global temperature change, so why don't we go with "coincidence". 1998 was a super el nino event, that explains the anomalous high temperature just fine.

    Move on, nothing more to see here folks...

     
  • At November 25, 2006 12:32 PM, Anonymous Anonymous said…

    If you download the World Radiation Center Total Solar Irradiance Data into an Excel spreadsheet and plot it with a trend line(I did - I can email the data and graph to anyone who wishes it), you will notice the there is on average, a decrease over the 30 year period, that equates to about 0.5% per millenia. Projected forward, anthropogenic effects asside, the earth will be completely frozen in about 100,000 years.

     
  • At November 25, 2006 10:50 PM, Blogger coby said…

    but of course there is no reason to think any such trend will continue.

     
  • At December 16, 2006 2:35 PM, Anonymous Anonymous said…

    I'm reviewing this section of the blog because it was the one of the very statements I heard last night (sans the stupid) from a skeptic. However, we didn't have time to debate so I suggested they allow me to email debate them, which they agreed.

    For this area of the blog, I'll reintroduce myself. I'm merely an adult student (that's a nice way of saying more mature than most students - not implying students are children) who recently did a research paper on global warming.

    Firstly, I'd like to acknowledge the wag the dog post for clarifying what isn't necessarily common knowledge, but i'll perhaps make a response to those items in the section designated for that topic.

    I guess I need some more clarification on how solar radiation or irradiation would be specific to global warming without current factors such as greenhouse gases. It is my understanding that greenhouse gases are what allows heat to stay in while otherwise releasing a large portion of it back into space. Therefore, an elimination of greenhouse gases could turn us into an ice age while over accumulation could scorch us. Am I missing the basics? Or, what would other factors be besides greenhouse gases?

    My research was following effects, but those were based upon greenhouse gases (i realize now that I'm reviewing things for this post). Furthermore, any discussion of carbon sinks vs. sources is also directly linked to greenhouse gases, but without greenhouse gases as the factor, what would the argument be for solar radiation heating up the earth or not?

    I can see there may be an argument if there is a shift in our planetary rotation, orbital rotation, and similar. Does anyone have some input they'd like to contribute that supports global warming or lack thereof based upon those types of factors? Of course you aren't limited to those factors if you have others to mention.

    Babs

     
  • At January 31, 2007 7:03 AM, Anonymous Anonymous said…

    1978-2007 us not enough data. You are neither proving or disproving anything with such a short timespan.

     
  • At January 31, 2007 12:00 PM, Blogger coby said…

    I disagree. If the sun has not warmed in the last 30 years it can be ruled out as the cause of an accelerating temperature change.

     
  • At February 02, 2007 6:04 PM, Anonymous Anonymous said…

    "there has been no increase in solar irradiance since at least 1978"

    Check your facts:

    http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2004/07/18/wsun18.xml&sSheet=/news/2004/07/18/ixnewstop.html


    Dr Sami Solanki, the director of the renowned Max Planck Institute for Solar System Research in Gottingen, Germany, who led the research, said: "The Sun has been at its strongest over the past 60 years and may now be affecting global temperatures.

    "The Sun is in a changed state. It is brighter than it was a few hundred years ago and this brightening started relatively recently - in the last 100 to 150 years."

    Dr Solanki said that the brighter Sun and higher levels of "greenhouse gases", such as carbon dioxide, both contributed to the change in the Earth's temperature but it was impossible to say which had the greater impact.

     
  • At February 02, 2007 6:16 PM, Blogger coby said…

    The sun reached this elevated level in the 1940's, thus it has been in an elevated state for the last 60 years AND there has been no trend for the last 60 years.

    Other quotes from your article:

    "He says that the increased solar brightness over the past 20 years has not been enough to cause the observed climate changes"

    "While the established view remains that the sun cannot be responsible for all the climate changes we have seen in the past 50 years or so, this study is certainly significant,"

    "He added, however, that the study also showed that over the past 20 years the number of sunspots had remained roughly constant, while the Earth's temperature had continued to increase."

    I would advise you once again not to get your science from popular media, environmental groups or oil industry funded think tanks.

     
  • At February 09, 2007 11:14 AM, Anonymous Anonymous said…

    gday Coby

    Just needing some feedback.

    Ive been here: http://www.junkscience.com/Greenhouse/cause.html. I would be interested in how you would debunk Milloys claims that it may be the sun (scroll down to 'what about the sun?')

    My opinion is that his comparison to % in the sun to % increase in earths temperature is mathematical BS - trickery. (i really dont trust milloy at all. I think he's completely dishonest BTW)

    Correct me if i'm wrong, but you should do things this way: You need to find out the watts involved. Looking at Lean's solar irradiance graph milloy provides it seems clear there has been no forcing for 50 years. OK. There has been an increase from 1900-1940. (my maths and figures may get real wonky from here on -please note!!!!!). From memory there has been there has been a net forcing of 1.7 w/m2 in the last century and a bit, and this corresponds to a warming of 0.6+oC (From understanding w/m2 and temperature are directly related via the stephan-boltzmann equation, so if you know one you can figure out the other? I have no idea how to perform the equation BTW). Ok, casting a very rough eye over the solar irradiance graph it looks to me that there has been no more than a 2 w/m2 increase in solar forcing over the period from 1900-1940 (1364.5 to 1366.5 W/m2). But thats at the top of the atmosphere. Earth's a sphere, so you divide those figures by 4. That gives you around roughly 340 w/m2 (thats what my calculator gave me anyhow). Times that amount by 0.7 to factor in a 30% albedo effect and you get very roughly 238 somewhere. Anyway i figured that there has roughly been around 0.3 W/m2 increase in forcing from the sun (this is something like IPCC estimates which is 0.06 - 0.3 in the latest SPM i believe) . Its all simply not enough for a 0.6 oC or 1.7 W/m2 warming. But thats just direct forcing and feedbacks might up that amount a little???? Could you please grade my math anyhow...im very rusty!

    Also, Milloy seems to be aware that there has been no increase in solar forcing for 50 years. He trys this trick: Claim that aerosols offset it for awhile. Ok sounds fair initially. My understanding however is that the phenomenon of global dimming has been going on well past the 80's into the 90's where it turned around a little. This means that there has been less and less solar forcing from 1950's - 60's (?) onward, all through the period that saw another temperature upswing from 1980. Therefore the idea thats its the sun, and that its forcing was offest by aerosols doesnt wash on that basis.

    Anyway, what do you think?

     
  • At February 09, 2007 11:46 AM, Blogger coby said…

    Hi Craig,

    I believe that you have Milloy nailed, both in your general impression and in his mathematics. What you did, accounting for albedo and the shape of the earth's surface, is precisely where he is (I have little doubt intentionally) wrong.

    About the direct relationship between W/m^2 and oC you also have to account for thermal inertia, which introduces a lag time of several decades before the equilibrium temperature you can calculate with the stephan-boltzmann equation is reached.

    I don't think global dimming is very well understood or at least well quantified. My impression is that it has been a decreasing factor in terms of particulate pollution but increasing in terms of contrails over land. A general decreasing trend over the late 20th is probably not an unreasonable hypothesis. So maybe Milloy is not too off base using that to explain a delayed effect, though it certainly stretches any claim of certainty, but clearly the total forcing even ignoring any dimming, from solar has not been nearly enough.

    Be sure to read RC's solar forcing articles for the straight dope! They have good stuff about aerosols too.

    Thanks for the comments.

     
  • At February 20, 2007 7:53 PM, Anonymous Anonymous said…

    By the very definition of Global Warming, the sun does cause Global Warming. My god, you neo-coms.

     
  • At February 23, 2007 1:54 PM, Anonymous Anonymous said…

    Does, but isn't.

     
  • At April 01, 2007 4:53 PM, Anonymous Anonymous said…

    Sorry Coby. NASA disagrees with you:

    http://www.nasa.gov/centers/goddard/news/topstory/2003/0313irradiance.html

    "Historical records of solar activity indicate that solar radiation has been increasing since the late 19th century. If a trend, comparable to the one found in this study, persisted throughout the 20th century, it would have provided a significant component of the global warming the Intergovernmental Panel on Climate Change reports to have occurred over the past 100 years," he said."

    Perhaps it is the sun, stupid...

     
  • At April 01, 2007 5:07 PM, Blogger coby said…

    Anonymouse,

    From your link:

    "Although the inferred increase of solar irradiance in 24 years, about 0.1 percent, is not enough to cause notable climate change, the trend would be important if maintained for a century or more."

    The IPCC attributes 10-30% of the total 20th century climate change to solar irradiance changes, I would call that significant. It is however less than that attributed to GHG's and the majority of that influence occurred prior to 1950.

    There is nothing in your provided link that is at odds with either the IPCC or the essence of this article. The sun has not changed enough, especially in the last 3 decades, to account for the rapidity and magnitude of the observed global climate change.

    Thanks for the comment.

     
  • At April 01, 2007 5:21 PM, Anonymous Anonymous said…

    Its a long-term cumulative effect. Stop cherry picking data from the last 20-30 years to support your hypothesis. That's misleading.

    From this report, the sun has been increasing in intensity for a century or more. Not surprisingly, the earth's temperature has increased for a century or more. Coincidence?

    The minimal change over the last 2-3 decades suggests the sun is getting ready to go into a reduced stage of activity. Indeed, the next 2 sunspot cycles are predicted to be SIGNIFICANTLY lower in intensity than they've been to over 100 years. If that turns out to be true (and the scientists studying the sun are pretty good at sunspot predictions) expect a return to temperatures more like what we had at the beginning of the 20th century.

     
  • At April 01, 2007 6:12 PM, Blogger coby said…

    Let's see... you are offering a single sentence out of a single report and I am cherry picking?

    Your own source does not support your contention. Observed solar trends are very small, get over it.

     
  • At April 01, 2007 9:59 PM, Anonymous Anonymous said…

    "Your own source does not support your contention."

    I'm speechless. I cannot fathom how you can read that research and then make that statement. It's clear this is a useless effort. Your blind devotion to the Church of Warming clearly leaves you unable to acknowledge new findings that could possibly go against your religion. Un-believeable.

    Peace out, Coby....

     
  • At May 18, 2007 2:52 PM, Anonymous Anonymous said…

    (Note -- this is a different anonymous from the posts on Apr. 1, although I agree with him on the science.)

    Irradiance is a red herring. Pretty much everyone agrees that the direct variation in solar irradiance is too small to cause the effect we observe.
    The controversy over the solar-activity connection centers on an indirect amplification mechanism which postulates that cosmic rays above a critical threshold energy (~10 GeV) significantly affect cloud nucleation, altering the planet's albedo. During periods of high solar activity (last several cycles had anomalously large sunspot numbers), the solar wind deflects more of these high-energy cosmic rays away from Earth, thereby reducing nucleation/cloud cover and increasing albedo. The best reference I can find is:

    http://www.sciencebits.com/CO2orSolar

    I am an engineer, not a climate scientist, but the data looks sound. It has been attacked (realclimate.org) but also defended (C14 and Be10 proxies measure lower-energy 1-GeV cosmic rays, one must look at the high-energy detectors only).

    The author thinks solar might account for perhaps 2/3 of 20th C. warming by this mechanism.

    One thing which occurred to me after reading this was to check whether there was a larger-than-average temperature rise near the 1958 solar max, which was the strongest on record (auroras seen in Mexico). The answer is yes:

    http://en.wikipedia.org/wiki/Temperature_record

    We see a little bigger-than-average bump around 1960. Don't know what to make of the lag, if anything.

    I agree this hypothesis should be testable in our lifetimes. The next solar max prediction (2011 or so) isn't dramatic, but the prediction for cycle 25 in 2022 is for dramatically reduced activity:

    http://science.nasa.gov/headlines/y2006/10may_longrange.htm

    So if the theory is correct, it should be possible to see a cooling bump around that time.

    If anyone has refutation of the papers on sciencebits.com other than the ones cited there, I'd be very interested to hear about them.

    Honest Skeptic (not of warming, just cause)

     
  • At May 18, 2007 2:57 PM, Anonymous Anonymous said…

    Errr, sorry -- that should be "reducing cloud cover and *reducing* albedo", of course. Less cloudiness == more absorption == warming. Sorry for the error.

    Honest Skeptic

     
  • At May 19, 2007 10:45 AM, Blogger coby said…

    Hi Honest,

    You are right that this article is not addressing the cosmic ray theory, but there are arguments out there about simple irradiance changes. I hope to add a GCR article at some point.

    You mention the RealClimate debunking of this idea, what do you think of their criticisms of the supposed correlation? Also, as a skeptic, are you really convinced that this is a well enough established idea, especially considering the very well supported theory that an enhanced greenhouse effect is causing the current warming?

    There are some other observations that the GCR hypothesis is a very long way from explaining, eg the temperature trend profile as you move from surface to stratosphere.

    Thanks for the comment!

     
  • At August 01, 2007 10:37 AM, Anonymous Anonymous said…

    Why is the temperature on Mars rising? Is it from human CO2 too?

     
  • At August 03, 2007 8:58 AM, Blogger coby said…

    The temperature on Mars may be rising in general, but the record is very short and very sparse. The most clear evidence of change is from retreating ice escarpments in the southern hemisphere and it is thought this is mostly the result of Mars' own orbital cycles similar to those that controled the timing of Earth's ice ages. There is some recent evidence from modeling experiments that indicate a small global martian warming due to its observed decreasing albedo. It is hypothesized that this change in albedo is the result of increased dust storm activities that generally darken the surface.

    You can find some additional response to the "Mars is warming" canard in the "Mars is warming" article. You might also google "hot times in the solar system".

     
  • At August 11, 2007 10:59 PM, Blogger jj mollo said…

    There has been a recent fuss about the adjustment of US record temperatures. This seems to be related to the condition of standalone weather stations. Do you know any more about this?

     
  • At August 11, 2007 11:02 PM, Blogger jj mollo said…

    The NASA giss link is empty, by the way. Frank Warner has a similar one with real data.

     
  • At August 11, 2007 11:23 PM, Blogger coby said…

    Hi jj,

    Check this very recent RC post for details on that. It seems McIntyre found a real error, GISS thanked him and made the corrections. It altered the relative rankings of the 1934 and 1998 anomalies in the US only making 1934 higher, though the difference both before and after was statistically insignificant. It caused no perceptible changes to the global or hemispheric trends.

    Errors happen, it is good to find them. Life goes on as will the fuss!

     
  • At August 12, 2007 12:26 AM, Blogger jj mollo said…

    That was fast. Thanks.

     
  • At March 03, 2008 9:47 PM, Blogger barry said…

    This comment has been removed by the author.

     
  • At March 03, 2008 9:49 PM, Blogger barry said…

    It takes 8 minutes for solar energy to reach the Earth. It takes a couple of hours for the surface to fully respond, which is why it is hotter at 1 - 2 pm than midday.

    The sun's output has actually gone down by a little bit over the last 30 years, although the decrease is not statistically significant.

    In order to validate the hypothesis that the sun is responsible for the last thirty years of warming when satellite records show no significant trend, it is necessary to explain why there is a 30 year lag in climate response.

    I don't think this has been attempted. Not successfully at least.

     
  • At April 10, 2008 6:35 PM, Anonymous Anonymous said…

    The Earth had an ice age thousands of years ago. The ice began to melt due to the climates temperature increasing (Global Warming)thousands of years ago..

    There were no factories, cars or fossil fuel burning devices of any type thousands of years ago. Yet the ice began to melt, there has been global warming taking place for a long time now naturally.

     
  • At April 12, 2008 2:57 AM, Anonymous Anonymous said…

    NASA Global Temperature analysis report us that it probably isn't the sun, "The year 2007 tied for second warmest in the period of instrumental data....The unusual warmth in 2007 is noteworthy because it occurs at a time when solar irradiance is at a minimum... here is the link: http://data.giss.nasa.gov/gistemp/2007/

     
  • At May 28, 2008 11:33 AM, Anonymous Anonymous said…

    The Earth had an ice age thousands of years ago. The ice began to melt due to the climates temperature increasing (Global Warming)thousands of years ago.

    There were no factories, cars or fossil fuel burning devices of any type thousands of years ago. Yet the ice began to melt, there has been global warming taking place for a long time now naturally.


    I'm pinching someone else's metaphor here, from another blog site;

    Last year I couldn't start my car. I had a flat battery.

    Today I couldn't start my car. The battery tested fine and testing indicated a faulty starter motor was the problem.

    Using the logic above, I would assume that my battery was flat today.

    (end paraphrase)

    There is nothing logical or scientific in assuming the same cause for warming. It's just... assumption.

    To deal with the above quote more substantively. The cause of ice ages is well established - Milankovitch cycles.

    Milankovitch cycles are periodic changes in the orbit, rotation, tilt, and proximity of the earth to the sun (amongst other astronomical variables to do with the way the Earth wobbles while it cruises around the sun).

    Ice ages coincide with Milankovitch cycles.

    Currently, we should be in a cooling period in the Milankovitch cycle, with the next ice age 30 - 40 thousand years away.

    IOW, we are currently heading into an ice age, not a warm period. The Earth should be cooling. It was - until 150 years ago.

    This is not to say that there is no variability in global climate between ice ages, or that warming and cooling periods over hundreds of years does not happen - it does.

    But the argument above has no merit - all the points in this post, even in the previous paragraph, which is well-established knowledge about climate change, demonstrate the paucity of the 'hypothesis'.

     
  • At July 04, 2008 6:07 PM, Anonymous Anonymous said…

    All these articles read like propaganda and spin. They say, Yes, you were correct, but from a certain angle and a certain way of thinking AGW is still happening. I still haven’t found the link that explains away the relationship between observed sun-spots and the emanated radiation which results interrelating with cosmic rays to affect cloud cover and so follows Earth’s service temp. The graph of the before mentioned much more closely correlate with observed temp change. I noticed the proposed “carbon tax” is carefully avoided, and the push for world government is not mentioned. This web-site is clearly one-sided and political. I see a lot of extra words that make the sentences convoluted. I do not sense straight talk. This web-site stinks of wrong-doing.

     

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