Open Thread: Anthropogenic Global Warming

Ok I need help.

Why is there so much controversy over climate change, and what are the facts?

There is so much debate between legitimate scientists, I have become very sceptical when reading anything that puts forward a strong opinion, either way, on human effects on global warming.  I find I am increasing unable to take either side very seriously anymore.

Note: I am not denying global warming at all.  My question is this:

Does human activity add significantly to global warming?

The Royal Society seems to think so.  This is the leading scientific authority in Britain that, in a peer-reviewed analysis, claims that humans are contributing significantly to global warming:

http://www.royalsoc.ac.uk/page.asp?id=4761

Yet, why have 19,000 American scientists signed a petition stating that this is not the case, and produced a comprehensive analysis of the trends of global temperature against industrial activity (and found no correlation):

http://www.oism.org/pproject/

Why have JunkScience.com offered $125,000 (as yet unclaimed) to anyone who can scientifically prove that humans are causing global warming:

http://ultimateglobalwarmingchallenge.com/

 

Bloggers that I share very many opinions with, believe in Anthropogenic Global Warming:

http://www.blacksunjournal.com/climate-change-facts/

And bloggers who I often agree with and respect a lot reject AGW:

http://ergosum.wordpress.com/category/environmentalism/

 

Al Gore’s “An Inconvenient Truth” has become very popular in advertising man’s putative effects on the planet.  But, when the film is replete with lies and distortions, I’m more inclined to think of it as something akin to creationist propaganda and politicking, than credible science.  You see, if the facts of mankind causing damage were that self-evident, why would so many people on both sides need to lie and attempt to deceive others about the evidence?

I am trying to keep my sanity here, so can someone tell me why there is even a debate?  Scientists don’t argue over the fact of gravity, or evolution, or heliocentrism etc?  In fact, scientists aren’t even debating that global warming is occurring.  The debate is whether it can be proven beyond reasonable doubt that man’s industrial activities are the primary cause.

As a rational thinker, I must go wherever the evidence leads.  However, I have no intention of getting swept up in purely political debates or emotionalism.  In other words, let’s propose for the purposes of this discussion that I don’t actually care if we are harming the environment or not.  I just want to know if we actually are.  At this moment in time, the only reasonable position I can take is one of agnosticism toward AGW, which means, I won’t accept it unless the evidence convinces me.  That is, I’m going to assume there’s not a problem unless someone can prove to me that there definitely is.  Call this naive if you will, but please be assured my only interest is the truth.

To any commenter’s: I will play Devil’s Advocate both ways; don’t take it personally!  😉  Who knows, by the end of this thread I will have reached a conclusion!…

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31 Responses to “Open Thread: Anthropogenic Global Warming”

  1. Euan Says:

    Mankind is pumping billions of tons of greenhouse gasses into the atmosphere every year (27 billion tons according to wikipedia) that were previously trapped in fossil fuel deposits that took hundreds of millions of years to form. That must be having an effect and it probably isn’t good.

  2. ordinarygirl Says:

    I found a good article at the New Scientist with a section on “Does CO2 Cause Warming?” that has some good information here:

    http://environment.newscientist.com/channel/earth/dn11462

  3. ordinarygirl Says:

    There’s also a good article up at Gristmill with a section about why climate change is happening.

    http://gristmill.grist.org/skeptics

    I’m not sure if these are the sorts of things you’re looking for or if you want more authority/consensus from scientists.

  4. arcanum Says:

    And a lot of biased scientists signed a petition against Darwinism. A quick peek revealed the fields of the signers was not clarified — what does your average social scientist, for example, know about climate change?

    Look at your sources when you want to determine the ‘truth’ of an issue. I’d trust the Royal Society (and a bunch of other reputable websites) over NewScientist any day of the week and twice on Sunday.

    Want graphic demonstration of the rise in temperatures? Look here http://upload.wikimedia.org/wikipedia/en/f/f4/Instrumental_Temperature_Record.png

    Want graphic demonstration of the anthropogenic rise in greenhouse gases? Look here

    I don’t think that there is any room for doubt that humans are causing global warming. In fact, matters would be even worse if our particulate pollution were not simultaeously causing ‘global dimming.’

    It’s not that I’m happy about this news, it’s just that I’m not selfishly motivated by greed and a desire to avoid personal inconvenience.

  5. TRM Says:

    Hi Evanscent,
    All of the above commentors not exactly correct.
    Heres what you do
    First study the history of the earth and its many climatic “ups and downs”.
    Second, Look at the solution’s being proposed to combat “global warming” , look who stands to profit and you will find a connection. The very notion to “issue” credits to dump carbon into the air is insane. WOW, they found a way to tax air…
    Always, study, study again, then form your opinion.
    Let me know if this helps…

  6. TRM Says:

    Oh yeah, I am one of those people that thinks its all a bunch of crap,
    remember the coming ice age in the 70’s?
    acid rain? the polluted oceans becoming void of all life in 10 years put out in 1982? DDT?

    Maybe I could find some scientist to give me some slides and I could start the next big scare…hmmmm

  7. Lynet Says:

    Actually, acid rain did have some nasty effects in East Germany, where the communists paid no attention to the environmentalist science. So they told me in German class, anyway.

    The question of why it’s so difficult to tell what’s going on actually has quite an interesting answer. One of the catalysts for the development of chaos theory was a weather prediction program developed by one Edward Lorenz in 1961. It had three main variables: temperature, pressure and humidity if I remember correctly. At any rate, at one point he decided to put in the numbers himself and run the simulation from halfway along — and got a completely different weather pattern. The reason? Rounding error in the numbers he’d put in.

    Systems of linear differential equations with three or more variables always have the potential to give chaotic results, that is, results which vary wildly even upon tiny changes in the parameters. Weather is, I guess, the paradigm case. Unlike gravity, where the mathematics is simple, when it comes to weather we have to work very hard to get results that are even halfway usable.

    It’s not that case that we can never tell anything about a chaotic system — weather does have discernable patterns, after all! For instance, where I live, the hot nor-wester tends to be followed by a horrible cold southerly. No doubt there’s some sort of understandable physical reason for that. Thing is, though, while we can find some things if we’re clever, we’ll probably always be guessing a bit — and just finding those guesses in the first place takes real ingenuity sometimes!

    I’ve got a cousin who studies geology who says that there is some geological evidence that higher levels of carbon dioxide in the atmosphere do make things warmer, on average. Unfortunately, I can’t give you details, though, even on how such evidence would work.

  8. sparkasynapse Says:

    What a frustrating issue. I think this issue has been so politicized that it would take serious digging to find out the truth. Personally, I think Al Gore is a total good for nothing liar. He’s admitted that there’s some amount of “theatrical heightening” needed to get people to care about climate change. On the other hand, the anti-global warming sources such as junkscience.com and The Great Global Warming Swindle, leave much to be desired, IMO.

    Here is a blog post I wrote some time ago on the issue, explaining my frustration. Within the comments, you’ll also find a good deal of links to various videos and other sources that address the issue of whether anthropogenic global warming is taking place.

    http://sparkasynapse.blogspot.com/2007/03/climate-change.html

    Here’s how I see the issue:

    • Is global warming a reality? (scientific question)
    • If it is a reality, is it man-made? (scientific question)
    • If it is a reality, is it a problem? (scientific question)
    • If it is a reality, and if it is a problem, should we or can we stop or prevent it? (philosophical and political question) Are we even in the position of having enough knowledge to construct a cost-benefit scenario right now? (a political, philosophical, and scientific question)

    My blog is not on wordpress, BTW. It’s on blogspot. I simply set up a temporary account at WordPress one day, but decided not to switch over.

  9. lichanos Says:

    Hi:

    I blog about this topic a bit, and I count myself a sceptic. I have also read some of the relevant papers and summaries. There are several facets to the issues you raise:

    Some people simply want to deny the possibility of serious change to the environment from human activity. The notion interferes with their religious or ideological commitment to laissez faire capitalism. People of this sort are not worth listening too, whether or not they are scientists.

    Be aware that what scientists will say in open letters, editorials, manifestos, etc. is very different from what they will say in a peer reviewed article. They are human after all. They like to vent and advocate too.

    There is a big difference between the confidence level required to make sensible policy and the confidence required to assert that something is scientifically proven. Personally, I support nearly all sustainability and energy reform measures, but not because I am convinced of the Global Warming argument – there are plenty of other reasons for my stance. Policy makers need to decide what is prudent even if they don’t have scientific proof. Plausibility may be enough, if the consequences of being not prudent are bad enough.

    Many people, including scientists, believe that unless people are scared, they will do nothing, i.e., not support the policies I mention above. Some of them are quite open about this. They are probably right that people will do nothing if not scared, but they are wrong to think that scaring people will get them to embrace a sensible course of action. Thus the drive to prove that a Green Policy is based on PROVEN sicence – then there’s no debate, unless you’re a troglodyte.

    Al Gore’s book (I didn’t see the movie) is a good example of this stuff. I wish he were president, but he’s no scientist. His book is basically a religious screed, and it is filled with ridiculous assertions.

    Finally, the science is not as certain as people say. They may be right, but to base long-term predictions on a stable database of temperatures from only the last 30 years, and to make predictions in the order of 1-6 degrees F, all on the basis of computer models that are presumed to embody correct representations of a system that is poorly understood, is a very far-fetched endeavor.

    Having worked closely with water quality modellers for years, I have come to think that the reliance on computer models is a fundamental corruption of the scientific method – there is no control. The model substitutes for testable theory. Okay for policy, maybe, but it’s not hard science. I just wish people could make this distinction, but what politician is going to advocate a Green Program on the basis of, “It seems we may have a problem, and it makes sense to be cautious.” Better to scream that the world is ending.

    You can search my blog or use my tags to find other posts I have made on this topic.

  10. lichanos Says:

    Oh yeah, forgot this one very important point.

    Often, you will see a graph of the supposed rise in global average temperature and the rise in CO2 concentration in the atmosphere. Some questions:

    Why don’t the graphs match exactly? What accounts for the “noise”. How do we know the noise doesn’t indicate a mechanism we don’t understand?

    Why is the correlation between CO2 and temperature assumed to be an explanation, a cause, rather than a correlation only? Because the model is based on CO2 as the cause, and the correlation bears it out. (The graph is from the model.) How do we know the model is correct? From the graph.

    What does global average temperature mean, and why is that a significant measure?

    Is the data as good as people claim?

  11. evanescent Says:

    Dear all,

    thanks for the comments so far. Please continue to do so. Don’t mistake my silence for non-presence. I would like to encourage as active a conversation as possible.

    One point though:
    lichanos said:

    The notion interferes with their religious or ideological commitment to laissez faire capitalism. People of this sort are not worth listening too, whether or not they are scientists.

    Like I said in the article, politics or belief should be irrelevant to this issue. I know people have vested interests either way, but facts are facts. Whilst interests will cloud how people present things, it shouldn’t cloud WHAT they present. Either there is conclusive evidence or there isn’t.

    Personally, I am more inclined to align myself with the laissez-faire capitalists, whether humans cause global warming or not, but that’s an issue for another thread.

    Please continue…

  12. Bruce Says:

    In a discussion of a controversial topic, it is not productive in my view to characterize a documentary on that topic as containing “lies and distortions” without exceptional proof not only of misstatements of fact but of the necessary element of intent to deceive or at least gross negligence as to accuracy on material matters.

  13. evanescent Says:

    Hi Bruce,

    I wasn’t characterising anything. What I said was a matter of fact. From one of the links I quoted above:


    * The film claims that melting snows on Mount Kilimanjaro evidence global warming. The Government’s expert was forced to concede that this is not correct.

    * The film suggests that evidence from ice cores proves that rising CO2 causes temperature increases over 650,000 years. The Court found that the film was misleading: over that period the rises in CO2 lagged behind the temperature rises by 800-2000 years.

    * The film uses emotive images of Hurricane Katrina and suggests that this has been caused by global warming. The Government’s expert had to accept that it was “not possible” to attribute one-off events to global warming.

    * The film shows the drying up of Lake Chad and claims that this was caused by global warming. The Government’s expert had to accept that this was not the case.

    * The film claims that a study showed that polar bears had drowned due to disappearing arctic ice. It turned out that Mr Gore had misread the study: in fact four polar bears drowned and this was because of a particularly violent storm.

    * The film threatens that global warming could stop the Gulf Stream throwing Europe into an ice age. The Claimant’s evidence was that this was a scientific impossibility.

    * The film blames global warming for species losses including coral reef bleaching. The Government could not find any evidence to support this claim.

    * The film suggests that sea levels could rise by 7m causing the displacement of millions of people. In fact the evidence is that sea levels are expected to rise by about 40cm over the next hundred years and that there is no such threat of massive migration.

    * The film claims that rising sea levels has caused the evacuation of certain Pacific islands to New Zealand. The Government are unable to substantiate this and the Court observed that this appears to be a false claim.

    So as you can see, I wasn’t being grossly negligent, inaccurate, or misstating anything.

  14. lichanos Says:

    Arcanum:

    You can’t just point to those graphs. First of all, they simply show a relationship, a correlation, not a cause and effect relationship. Then there is the endless debate about the details of the those graphs – the accuracy of the temperature data before 1970, etc.

    Did you look at the scale of the graph? We’re not talking about big changes here, and the graph starts in the negative region!

    Things are changing…in some places. They may continue to change in the same direction…They may not continue at the same rate…We may be contributing to it, a bit, a lot, hardly at all…

    It’s not as open-shut as you say. Dip into the science papers in the IPCC report, NOT just the executive summary – it’s got a whole different tone to it.

  15. Ebonmuse Says:

    Hi evanescent – a few comments:

    First, that “19,000” signature petition is very likely to be overblown. Many of those names have not been authenticated; many don’t seem to belong to anyone with any relevant scientific credentials; and many are simply fraudulent. You’ll note that the petition site itself simply lists names with no academic affiliation or contact info given.

    The Wikipedia article on this petition has some useful links and analysis. Scientific American, for instance, sampled a handful of the signatories. Some it simply could not identify, and of the ones it could, some of them did not remember it, denied having signed it, or stated that they no longer agreed with it. Before we cite this petition as evidence, I think it’s legitimate to ask for a total revalidation of all the names listed on it and a posting of contact information so that independent parties can verify the signatories’ position and credentials for themselves.

    As for the JunkScience.com offer, it costs money to submit an entry, and the people running the site say that they themselves will be the sole judges of whether an entry meets their challenge criteria. Small wonder that real scientists haven’t been interested in playing that game. Not even Kent Hovind actually tried to charge people to participate in his rigged challenge.

    One more comment, on this court ruling about the supposed “errors” in An Inconvenient Truth: the site you link to has blatantly misrepresented the outcome of that trial. The judge in that case did not rule that the film contained “nine material falsehoods”. As usual, the fault lies with lazy journalists repeating each other’s mistakes, and biased commenters seizing on those mistakes. What actually happened is that the judge, in his ruling, referred not to errors but to “errors”. In other words, he was using the plaintiff’s term in scare quotes. His decision was not that the film was scientifically inaccurate on those points – in fact, he explicitly said he wasn’t attempting to determine that. Instead, what he found is that there are some points in which the film differs from the IPCC consensus report, and that opposing views should be presented on those points for balance if the film is shown in schools. See:

    http://scienceblogs.com/deltoid/2007/10/an_error_is_not_the_same_thing.php

  16. owen59 Says:

    There are two other thoughts I would proffer:
    1. Much of science is built on disproving the hypothesis because this is usually easier then proving. So a question of proof might be for any evidence that disproves the hypothesis for AGW to be declared.
    2. The question for human society is how can we improve governance so that it becomes more democratic in nature and more efficient in response to any changes in community conditions be it environmental or economic.

  17. Geno Says:

    Of course there is global warming. Who would deny it – we used to live in an Ice Age. Man used to freeze his ass off and get chased around by Whooly Mammoths. Geez, who wants to go back to that era.
    So, what did man do back then to melt away 90% of the ice covering the earth? Nothing!

    Now I am not saying that we can’t do things better ourselves to stop the so called “greenhouse effect”, but let’s be serious. Most scientist and politicians don’t really care about solving the problem. What they are most concerned about is punishing the US and some western Europeans.

    If they were serious, they would include the largest world polluters in the solution instead of giving them a pass. Who are bigger polluters than China and India. Until they are included as being 100% responsible to clean up their act, I will just assumes that all of this global warming is just political posturing.

  18. nouseforadave Says:

    May I suggest checking out realclimate.org, especially the Highlights section on the right hand side.

    Its a blog run by climate scientists currently active in the field.

  19. devildog6771 Says:

    I think common sense would say that as we develop more and more of the earth, we will have an environmental impact. That impact will be broad ranged and dependent upon the availability of resources for one thing. Next would be our impact on other species of wildlife and marine life. The land mass and water resources are a third area. It only stands to reason we will impact the quality of air.

    Forestry helps replenish our our oxygen. That is no secret. We have developed 80% of available land mass already. Of course we could follow the trend of places like the Emirates where they build huge flotation peers and develop on them. But, even that will only be practical to a point.

    How fast will the “green house effect” become critical is to a extent up to us on one hand and nature on the other. We can’t agree on the nature part I think because of the controversy over creationism and evolution.

    Personally I say what is the big deal here. An omnipotent being created the Earth in six days and rested on the seventh. Is it not possible that that seven days in respect to how that being knows it and how we know it are relative. In ancient times milliniums were beyond their comprehension just like the fact that the earth was round was beyond the early explorers until they developed the means to explore. Even then, news of a round world wasn’t immediately accepted.

    Regardless of whether we are in immediate crisis or not, it is only prudent that as we expend the earth’s resources, we try to find alternatives? The problem here is a greedy oil industry. Of course they aren’t the only greedy conglomerates. Why do you think Globilization with less emphasis national allegience is such a big thing?

    Secret organizations of wealthy men [like Bill Clinton and the older Bush] control the banking industry, the oil industry and any other major industry. They control national politics and the rise and fall of nations. We have more to fear from them than global warming because they are going to bleed every dollar they can before any changes are made in alternative fuels, whatever. They even control or manipulate trade agreements.

    The North American Union and the European Union benefit them far more than the rest of the earth’s population! Have you ever read “Red Mars,” “Green Mars,” and “Blue Mars?” They are an excellent study in this area as is the ‘Dragons of Pern” Series by Anne McCathery. The theme is a little more subtle in the Pern series.

    The main theme about the evolution de-evolution, re-evolution of a society is one we might study closely!

    Anyway, I am sure few will see why I chose this approach to the topic. It makes sense to me. I may have done a poor job of explanation, but I hope it did give food for thought!

  20. Geno Says:

    devildog6771’s statement above is what I was talking about. All of this global warming stuff is about the “bad” US and “bad” people like Clinton and Bush.

    It’s not about science at all – please note that he made no mention of the biggest offenders of good environmental policy – China and India.

    See, if it’s Bush and Clinton’s fault, I can wait for them to die and then the problem will be over. But if the pollution problem is at the feet of giant 3rd world countries that everyone is afraid to confront, then it won’t be taken seriously and I will continue to drive my big SUV.

  21. evanescent Says:

    @ ordinarygirl: thanks for the links and comments! A big help!

    @ arcanum: thanks for the links and graphs.

    @ lichanos: thanks for the good feedback and comments so far!

    @ Ebonmuse: I was really hoping you’d drop by! I know this is a topic you feel strongly about, and we agree on so many other things, but I’ve been unsure myself with all the contradictory POVs flying around! Thanks for the links too, and the clarification of “An Inconvenient Truth”.

    @ Geno: you’re right. I don’t think it’s possible to see either side of the debate without some scepticism, as both sides seem to have vested political interests.

    @ nouseforadave: great link, thanks!

    @ devildog: For mankind to survive and flourish, my primary concern is with human welfare, not wildlife. I’m not being a badass, just saying that I wouldn’t put animal welfare above human welfare.
    I agree with you that energy alternatives are imperative for human survival. And I also agree that we should take care of the environment if the alternate would cause harm to our race.
    I’m not sure about your Clinton/Bush secret organisation conspiracy theory though!

    Geno said:

    …then it won’t be taken seriously and I will continue to drive my big SUV.

    At the moment, this is my position too. (Except I don’t have an SUV). I don’t think we can put our lives on hold but I don’t think we can ignore a problem that could threaten our species. I don’t have a problem exploiting the earth’s resources, but I will if in the process we are harming ourselves!

    Anyway, because of all the excellent links provided I have much reading to do now!…

  22. Misanthropic Scott Says:

    Hi evanescent,

    First and foremost, I must point out that in the absence of the peer review process, people can say anything they want about climate change. There is also tremendous profit incentive to do so. Exxon has offered money to any scientist that disputes global warming. For many years prior to now, many other organizations did as well.

    The peer review process is not perfect. However, it is the best means we have at the moment to ensure that the content is not pure drivel. It is often hard to read true scientific publications. In such cases, I would suggest at least watching for reputable news publications that explicitly cite journals such as Nature and Science. The will likely do a decent job of paraphrasing the true peer-reviewed work. You can find the true peer reviewed articles using http://scholar.google.com, though the articles may not be free.

    I don’t know if you would be willing to read full length books on the subject. If so, here are a couple of good ones to start with. The first, despite being a textbook, is actually much lighter, shorter, and less depressing than the second, though both are excellent.

    Is the Temperature Rising: The Uncertain Science of Global Warming – S. George Philander: A relatively light book and highly readable for a climate science text book.

    The Weather Makers – Tim Flannery: Details the reality of anthropogenic climate change. What is known, what is not, what we must do, and what can and cannot be saved.

    As far as I know, the only controversies over global warming in the peer reviewed publications are:

    1) What is the percentage contribution from the current increase in solar radiation? I’ve not heard any article claim higher than 5-30%, and that was a single article. Others claimed 5-15%. However, even if you go with the extreme estimate of 30%, we are still left as responsible for the other 70%.

    2) How bad will the effects be? Many articles attempt to quantify the anthropogenic global warming. This is very difficult. The range of possibilities is quite wide. However, keep in mind that even the conservative estimates are for quite devastating effects.

    3) What local effects will occur? This is the hardest part of climate modeling. Climate is far easier to predict than weather. Global climate is far easier to predict than local. The more local the forecast, the more uncertainty it is likely to have.

    Lastly, please keep in mind the existence of the IPCC and their forecasts. The IPCC is the most conservative climate science organization on the planet. They are made up of hundreds of scientists from over a hundred nations. In order for them to publish anything at all, they must first reach consensus.

    This means that climate scientists picked by the governments of Saudi Arabia (the largest oil exporter with 96% of their economy dependent on oil exports), China (the largest coal burning nation in the world), The United States (the largest oil importer in the world and, by far, the largest per capita contributor of CO2 in the world), and Australia (the largest coal exporter in the world and the country that pressured Tuvalu into not making any statement about their nation sinking into the sea at Kyoto).

    When all of these scientists make statements such as being 90% confident that global warming is real and human caused or that there will be a billion climate refugees by 2050, the one thing of which you may be certain is that the estimates are conservative and likely to fall short of the truth.

    Already, the latest IPCC report is being criticized heavily for being too conservative, as were all of the previous reports.

    http://www.spiegel.de/international/world/0,1518,518231,00html

    There are numerous articles stating that current observations are all near or over the worst case predictions of earlier IPCC reports. The current one is likely to be no exception in coming up short of reality.

    Anyway, just my $1,000,000,000.02. Sorry if my rant is a tad over the top. I hope you’ll find it informative and do some further reading.

  23. lichanos Says:

    Misanthropic Scott:

    Hi – when you read the IPCC documents, you have to read the papers as well as the summaries. They seem to be written in two different worlds. They are. One is science, one is policy. I happen to agree with a lot of the policy stuff, but I doubt the science. I don’t think that matters – we can’t wait to be absolutely sure before doing anything.

    My main gripe with the putative scientific claims is that they are all, fundamentally, based on computer models. I don’t see how a computer model can prove anything. You can say that if the predictions are born out in the real world, it is proven, but then there is the question of how you know this is true? How many years are required, how many data points, an average, min and max? It gets very messy and uncertain.

    The work to date convinces me that human inputs are a plausible cause of some of the warming, that’s all.

    Reading the statements that even scientists make about confidence levels can be quite disheartening. They turn out, on close inspection, to be very fuzzy indeed.

    One example – Recently, I believe it was the IPCC, a group said that it was 90% certain that most of the observed warming was caused by human inputs. If we take “most” to mean at least 51%, and if we use standard methods to assign the probable value (0.90 x 0.51) we get a statement that about 45% of the warming is caused by human inputs.

    This leaves me with one big question – what is the cause of the other 55%? Noise in the model? Natural variability? Doesn’t this make it a bit uncertain that we really understand the system well enough to have confidence in our millions of lines of code? This is my point.

  24. Misanthropic Scott Says:

    lichanos,

    I’m glad we agree about policy. Unfortunately, little or nothing is actually being done. We are still increasing our CO2 output.

    With respect to the IPCC statements though, I think that in a case where hundreds of people scrutinize every word, it is important to quote the group exactly. The actual statement may be found at the following UN website.

    http://tinyurl.com/3cezuo

    The full quote is:

    The Intergovernmental Panel on Climate Change (IPCC) concludes that major advances in climate modelling and the collection and analysis of data now give scientists “very high confidence” (at least a 9 out of 10 chance of being correct) in their understanding of how human activities are causing the world to warm. This level of confidence is much greater than what could be achieved in 2001 when the IPCC issued its last major report.

    Given the way that this is worded, I do not believe that you can multiply numbers together the way that you have. Further, of the peer reviewed scientific publications, the only cause of global warming that is not human that gets any press, is the increase in solar radiation. Most articles put that number at 5-15% of the observed global warming. One that I saw claimed 5-30%. Even if you take this last extreme, it leaves humans responsible for at least 70% of the observed warming.

    With respect to modeling, it is important to recognize that there are many models in use, probably over a dozen or more. The output from the models produces a range of predictions. However, when all of the models are in agreement on the basic point that global warming is human caused, it is a powerful statement. It is not about confidence in one set of millions of lines of code. It is about confidence that a dozen different models, each with their own millions of lines of code, agreeing with each other constitutes the best evidence we can obtain with present technology.

    Further, some of these models have been in existence long enough to have made predictions that now match observations. Actually, the predictions made by the IPCC consistently fall short of actual observations. The observations thus far are all near or above the high end (worst case) of all prior IPCC predictions. And, as noted in my post above, there is already a body of scientific opinion forming stating that the same will be true of the current IPCC report.

    So, if it makes you feel good to believe that 55% of global warming still requires accounting, go for it. But, the existing scientific evidence does not support that. It supports a number more like 5-15% and the cause is known, increased solar radiation.

    Is it possible that the vast majority of climate scientists on the planet have it wrong? Of course. I, for one, am not willing to bet the survival of our species, and of many species I find more beautiful than our own, on that long shot.

  25. lichanos Says:

    M-Scott:

    Regarding your unwillingness to play Russian Roulette with our planet, I agree. That’s why I support sustainable initiatives of all kinds. I’m also pessimistic that enough of that will be done worldwide, but on the other hand, when I talk to young engineers and architects, they are all heavily into that, so maybe the next generation will start doing things differently across the board.

    There are so many reason to pursue that course, aside from global warming. (You might be interested in my blog post on my environmental golden rule:

    http://iamyouasheisme.wordpress.com/2007/10/22/environmental-golden-rule/

    My scepticism about the scientific validity of many of the claims is based on my reading of papers, my attendance at many seminars, my contact with modelers and climatologists at the GISS (Goddard), and my work for twelve years with a firm that made its name doing environmental modeling, primarily of large natural water systems. I just can’t place confidence in models the way you and these scientists do.

    I believe that models substitute for theory. You can’t really do an experiment to prove them wrong definitively. The assessment of their accuracy is a statistical matter, and it is based on data which is itself, statistical in nature. In the end, they are predicting changes of a very small magnitude (I know that small changes can be significant nevertheless for ecology) over a long period.

    Almost without fail, when I speak to an earth scientist outside the orbit of climate-change funding and ask them their opinion, their response is a shrug, and “maybe…we’ll see.”

  26. Misanthropic Scott Says:

    lichanos,

    Since you don’t like the models, let’s try another approach. Are you aware that due to the higher albedo of Venus, despite its shorter distance to the sun, less sunlight actually gets through to the surface of Venus than gets through to the surface of Earth. Venus absorbs just 25% of the sunlight that hits it; Earth absorbs 70% of its sunlight.

    Without the effects of greenhouse gases the average temperature of the surfaces of the two planets would be Earth: -18 celcius Venus: -41 celcius. With greenhouse gases, especially CO2 in the case of Venus, the average temperatures on the surface of these planets are Earth: +15 celcius and Venus: +430 celcius.

    So, if CO2 is enough to cause Venus to go from -41 celcius to +430 celcius, even without modeling, I think it is incredibly obvious that doubling our CO2 will cause severe global warming. Do you see it otherwise? If so, how?

    These numbers were taken from the climate science text book ‘Is the Temperature Rising? The Uncertain Science of Global Warming’ by S. George Philander.

  27. lichanos Says:

    Well, CO2 is a “greenhouse” gas, no question. I don’t know what the concentration of it in the atmosphere of Venus is, but sure, it is part of why that place is not an icebox. But as I recall, Venus is shrouded by all sorts of vapors. Water vapor? (There is a story in The Illustrated Man that has some spaceship wrecked guys struggling through the endless rain.) Water vapor is MORE of a greenhouse gas than CO2. The devil is all in the details.

    Earth has oceans, they absorb CO2. The rate at which they do so is not certain. The dynamics of clouds and water vapor distribution are uncertain here. Finally, as I said, we are talking about changes of a few degrees over many years – that’s awfully hard to predict with any certainty.

  28. evanescent Says:

    The reason Venus is the hottest planet in the solar system is because of its incredible greenhouse effect. I remember reading that Venus’ unusual tectonic system doesn’t help either.

    The greenhouse effect causes incredible global warming on Venus, but Venus’ atmosphere is miles and miles of thick sulphuric acid and carbon dioxide. Venus is also much closer to the sun than we are. And it has no carbon cycle or lifeforms to reabsorb carbon. So I don’t think it’s fair to compare Venus to the earth.

  29. Lenoxus Says:

    “Water vapor is MORE of a greenhouse gas than CO2. The devil is all in the details.” An important detail being, of course, that water is naturally re-absorbed much more frequently than CO2. What about that?

    “Earth has oceans, they absorb CO2. The rate at which they do so is not certain.” Wait, an uncertain variable? Someone needs to tell the climatologists they’re obviously wasting their time…

  30. The Celtic Chimp Says:

    This is one seriously irritating debate. As you say there is a severe lack of concensus and evidence both ways. I think Lynet is right about why. There are just too many variables, to much interaction between them and too many unknowns. You get different results depending on how you look at the problem. What ever the case actually is, the way in which this issue is usurped for political agendas is really really irritating. The sheer amount of money wasted on initiatives that wouldn’t help even if there is a problem is maddening.


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