Jan 22 2010

NASA – Last Decade Warmest on Record

I have never had a strong opinion on global climate change. The data is too esoteric and complex for a non-specialist, in my opinion, to have a firm grasp on it. So climate change is one area where I am content to defer to the consensus of expert opinion. I understand the basic arguments, and find them plausible and even compelling. I have listened to the dissidents, and do not find their arguments compelling. Maybe they have a point about the limitations of our ability to project climate into the future and understand all the consequences and remedies. Otherwise I find their argument severely wanting.

To be fair, “dissidents” comprise a fairly broad range of opinion in my experience, from mild skepticism to dedicated ideological denial. So they defy a single label or attempt to characterize their position, and any such attempt inevitably leads to angry responses from those who feel they have been treated unfairly. And further, there is ideology and extremism on the other side as well.

For me – probably like most people, I just want to understand the facts. I don’t really have any ideological stake in this debate. If there is anthropogenic global warming (which there seems to be) I think we should take reasonable steps to mitigate it. If there isn’t, then I don’t want us to waste our resources chasing our tail.

The most basic factual question is whether or not average global temperature is increasing. It seems like this should be a fairly straightforward question, but on closer inspection it is quite complex. But despite this, it seems like the kind of data that should easily lead to a consensus of scientific opinion. From my reading it has, but this scientific consensus has not translated into a public consensus. At times I hear dissidents say that they accept the climate is warming, they are just not convinced it is anthropogenic. Yet it also seems dissidents will seize upon any opportunity to cast doubt on whether or not warming is even occurring.

Certainly the public political dissidents from AGW deny the warming. George Will, who writes occasionally on this topic, has been repeating the claim that temperatures have leveled off, and may even cool. He wrote in his column:

By asserting that the absence of significant warming since 1998 is a mere “plateau,” not warming’s apogee, the Times assures readers who are alarmed about climate change that the paper knows the future and that warming will continue: Do not despair, bad news will resume.

Pat Buchanan has called global warming a “hoax and a scam” and doubts that warming is even happening.

And of course when the climategate e-mails broke they were followed by accusations that the basic premise of AGW – rising global temperatures – was scientific fraud.

So is the Earth warming or not? NASA is an agency that gathers information relevant to this question. They recently released their analysis of the last decade and concluded that average global temperatures from 2000-2009 in fact were the warmest on record – since we began directly measuring temperatures in 1880. 2009 was tied for the second warmest year on record, despite an unusually frigid December. This is based on the pooled data from many sources:

GISS uses publicly available data from three sources to conduct its temperature analysis. The sources are weather data from more than a thousand meteorological stations around the world, satellite observations of sea surface temperatures, and Antarctic research station measurements.

Other research groups also track global temperature trends but use different analysis techniques. The Met Office Hadley Centre in the United Kingdom uses similar input measurements as GISS, for example, but it omits large areas of the Arctic and Antarctic where monitoring stations are sparse.

Although the two methods produce slightly differing results in the annual rankings, the decadal trends in the two records are essentially identical.

That sounds pretty solid. But there is so much complexity in gathering and assessing this data, that it is unlikely to convince any global warming skeptics. Already they are posting their doubts about NASA’s data.

Here is my layman’s understanding of why the data is so complex. First, we are trying to compare temperature measurements from across decades. This assumes that the method of measurement is consistent – same instruments and calibration under the same conditions. If a building was added in 1940 that throws a shadow on a measuring station, then that changes the measurements. Or if different shielding methods are used to prevent direct warming by sunlight. Often temperature data needs to be adjusted to account for these changes – adjustments introduce the opportunity for more judgments and mistakes, and therefore more doubt.

Perhaps the largest source of confusion about temperature data is that climate scientists are trying to pick out a trend in average temperatures, which is tiny compared to the variations in temperature. Of course, temperatures vary greatly throughout each day, they will change with cloud cover, and they will vary by season. There are also numerous short term and local trends in climate. We had a cold December in North America because of an unusually strong La Nina effect bringing down Arctic air.

So temperatures are averaged, by day, by year, by decade, and across the globe – more than a thousand stations. That’s a lot of averaging. The public has to basically trust that the scientists are doing their jobs correctly, weeding out bias, and getting all the complex math right. Of course, no such project this massive will be without error and differing opinions about methods – so the scientific literature is full of articles on “unresolved issues” and conflicting data.

And in the end we have to trust scientists that they were able to detect a global warming trend of 1.5 degrees C since 1880, on the backdrop of all the local and short term fluctuations. I do trust the consensus (NASA can send out a probe and hit Saturn, so they have earned some trust) and I have not heard any arguments that I find compelling to distrust it. But I also understand why many in the public find it difficult to trust.

We also need to keep our logic clear. More often than not, when discussing the issue of climate change with a dissident, I hear arguments that essentially try to cast doubt on global warming by citing evidence of cooling that is either local or short term. This is reinforced by hard core doubters. For example, the Drudge Report (a conservative news aggregator) loves to run stories about how cold it is, and reveled in the fact that the Copenhagen summit was met by freezing temperatures (that may have had something to do with the fact that it was December in Copenhagen).

So let’s dispense with these arguments – there will be short term and local fluctuations in temperatures. There are many climate trends superimposed over each other. The claim of AGW scientists is that when you control for all known trends and fluctuations in climate, there is an extra warming trend of about 1.5 degrees C in the last century. This trend cannot be accounted for by any natural process, but can potentially be accounted for by forcing from greenhouse gases. That’s the claim – if you are going to doubt it, then at least address it – not some straw man about how cold it was in December, or the solar cycle, or some other trend that is already accounted for.

In the past climate science was an innocuous discipline, and the scientists fairly anonymous. Now they have been thrust into the middle of a raging political controversy, and big decisions are hinging on their data and analysis. I get the sense (reinforced by climategate) that the climatology community has not fully adapted to this reality. There is an opportunity now to accelerate this process. There needs to be more transparency in temperature data and its analysis, not because I think there is any fraud going on, but because we need transparency in order to have public confidence in the science.

Scientists may find it inconvenient and annoying, and would rather just limit their dealings to other scientists – but it’s too late for that. They have to learn how to deal with the public and with governments and politicians, and especially their critics, in an effective way. It’s not enough to have good science – society needs to trust it and make use of it.

71 responses so far

71 Responses to “NASA – Last Decade Warmest on Record”

  1. wesleysabneyon 22 Jan 2010 at 10:55 am

    Thanks so much for this post Steven – This is by far the most reasonable, measured response to climate change I’ve seen. Well put – thanks for doing so much hard work for skepticism and rationality!

  2. johncon 22 Jan 2010 at 11:12 am

    All good points, but after CRU debacle, the data itself needs more scrutiny before any conclusions are made about trends.

    Even then we have to make sure our understanding of natural trends is complete before we can assess so-called ‘unnatural’ trends like AGW.

    So data we don’t trust yet plus a system we don’t understand yet equals very little in the way of evidence.

    The economics of climate change policy and the carbon trading markets are far more certain, if that’s any consolation…

  3. Steven Novellaon 22 Jan 2010 at 11:23 am

    Yes, but like in many arenas – climatology is now an applied science, not just a basic science. Which means we have to make decisions (not taking action is a decision) in the absence of perfect data.

    Almost by definition we cannot wait until we are certain about AGW before we act.

    So it is reasonable to entertain courses of action that might help mitigate AGW without dismantling our economy or doing anything hysterical. That is the middle ground that seems to get lost in the heated debate, which seems to create a false dichotomy of do nothing, or panic and change everything.

  4. CrookedTimberon 22 Jan 2010 at 11:46 am

    Unfortunately it seems no one told the melting glaciers to wait until all the deniers were satisfied with the temperature recording nuances. The changing migration patterns and life cycles of certain species also seem to have been uninformed. Perhaps they are just in on the conspiracy.

  5. James Severinon 22 Jan 2010 at 11:50 am

    I struggle with the same problems, I’m just an interested layman without the benefit of a PhD. or any other consonants attached to my name. I try to grasp the concepts of the science but as you pointed out Dr. this is an area WAY beyond my comprehension. I just wish there was some kind of obvious and simple evidence for AGW presented to the general public.

    Further muddying the waters for me is that when I was a kid it was all about CFC’s and the ozone layer, now it’s carbon emissions which boggles my mind.

    As a (practicing) skeptic I will change my world view when appropriate, in this case though I have very little to go on that I can comprehend.

  6. tmac57on 22 Jan 2010 at 11:53 am

    Fasten your seatbelt Dr. N ,its going to be a bumpy ride.

  7. Fred Cunninghamon 22 Jan 2010 at 12:08 pm

    By chance I just emailed you a photo that represents one more tiny bit of evidence of warming. While the average temperature data may be hard to analyze, loss of polar ice is significant. I have seen pretty good rebuttals to all the claims put forth so far by those who do not believe that our activities are a major factor in warming. Clean energy should be our highest priority.

  8. HHCon 22 Jan 2010 at 12:25 pm

    Why would the data show a leveling of temperatures from 1940’s through the 1970’s? Nuclear explosions occured during this period from released bombs and bomb tests. Industrial development expanded and accelerated after WWII.

  9. Ashon 22 Jan 2010 at 12:25 pm

    Nice to see a reasonably balanced article on this topic. Most of what you read seems to be based on ideological extremes. I’m probably like you in that I have a good general science background, some background in atmospheric science, but am not a climatologist and believe a lot of the science related to global warming is beyond me – that’s why we have experts who devote their lives to studying it. Obviously there are natural changes in climate, but to me it seems reasonable that we can have an effect on climate too.

    My main problem relates to the ideological extremes oversimplifying the issues. One side is convinced any changes (if there are any) are natural, while the other side seems to look only at the anthropogenic contribution, and either ignore natural changes or assume they would not be harmful to us – something I do not think it is appropriate to assume; any significant change in climate (whether warmer or cooler, and regardless of whether it is natural or anthropogenic) would have some pretty major effects on humans.

  10. Jim Shaveron 22 Jan 2010 at 12:26 pm


    I had the same reaction as CrookedTimber and Fred Cunningham, in that I was surprised not to see any mention in your article of the melting glaciers around the world and the melting ice sheets in Greenland and Antarctica. The before-and-after pictures are astounding. If I understand correctly, in many cases ice has receded to levels not seen in many centuries.

    If all that melting ice data is true (and it certainly seems convincing), I don’t understand why scientists don’t just show those pictures to the deniers. The ice is gone. Case closed.

  11. CrookedTimberon 22 Jan 2010 at 12:43 pm

    RE: James Severin
    There are a couple decent popular science books that will take you through the evidence. One I found informative is “Global Warming: Understanding The Forecast” As a fellow non expert, I found it accessible yet thorough.

    If I’ve learned anything from this and other skeptical blogs it is that a convergence of evidence is compelling. Just as no one aspect of evolution stands alone yet it is irrefutable as a whole.
    Aside from the details of the evidence (which is compelling) what are the odds that thousands of scientists from differing fields such as climatology, glaciology (sp?), atmospheric science, geology, biology, etc. are all wrong in the same direction?

    Unless of course they are all meeting in secret at some far flung location hosted by the Bilderberg Group to conspire to adjust the data.

  12. kelskenon 22 Jan 2010 at 1:05 pm


    Your focus on the facts of issues is the one of the most compelling reasons to read your blog, and this post was no exception. It seems clear to me the climate is warming. Of course the most important questions are whether this is a trend, whether it is driven by mankind (I hate that A word), and can we or should we do anything about it?

    Frankly I doubt any action will be taken to change our mankind’s behavior.

    On a side note, recently the program Nova ran a three part series on the evolution of homo sapiens, and one theory that was promoted was that rapid climate change in Africa was a selection factor that drove the evolution of humans. Changing climates drove selection of only the most innovative primates.

    So, perhaps, this avoidance of action on climate change is merely a subliminal (in)action on our part to further drive our evolution.

  13. mlegoweron 22 Jan 2010 at 1:08 pm

    Here’s what I don’t understand, and I don’t claim that warming isn’t happening or even that it isn’t anthropogenic: Why do I always see charts of the last decade or so when AGW proponents are making their claims? The average educated person looking at those MUST immediately claim, “Small sample problem,” right?

    I agree that if these scientists really believe it’s happening and there’s a good chance it’s primarily due to humans that the truth probably lies closer to that than the opinions of Pat Buchanan. Still, can they not find more compelling ways to present this information to the layperson, or even the statistically savvy audience. The polar ice chart Phil Plait recently posted is a great example. 1) It only covers years since 2002 and 2) it graphs the level of changes in polar ice mass, in other words the derivative of the actual mass. When I look at it I think 2 things. First, that 6 years of data is relatively insignificant even when considering human history, to say nothing of geological history. Second that a graph (which is sharply downward sloping) showing the derivative of polar ice mass is mildly deceptive and may be misinterpreted by a large portion of the audience as the actual levels of mass declining sharply. What it actually depicts is positive rates of change prior to 2006 dropping below zero (in other words, evidence of decreasing mass) after that. It indicates to me some local maximum in ice mass that occurred around 2006, but without knowing what the long term trend looks like, I can’t tell whether a local maximum like that is a common occurrence or real cause for alarm.

    So I plead with the climate scientists: find a way to graphically depict your evidence which is compelling but not deceptive. It can’t be too hard if the evidence exists, which I truly believe it does.

  14. Timmysonon 22 Jan 2010 at 1:14 pm

    Bjorn Lomborg is a statistician who claims to have debunked a lot of the claims made about AGW, including (which I found most interesting) volatile weather. It’s the best argument against which I have found, in a sea of ideological arguments that discredit the position. I would be interested to hear what you think of his work.

  15. CWon 22 Jan 2010 at 1:22 pm

    I was thinking of a response to the claims “small sample size” and “look back hundreds/thousands of years ago” and came up with this:

    If a large asteroid was heading directly for the Earth, would we look back to see what past asteroids of the same size did – before generating a response?

    I guess my point is, unlike most science studies where there is not a perceived imminent threat – we can take the time to do multiple studies of varying degrees of time. But with something as significant as climate-change, which could have a profound effect on our planet – I think it’s reasonable to look at short term studies as suficient evidence to respond in a reasonable way (that doesn’t include crippling our economy or greatly changing our way of life).

  16. mlegoweron 22 Jan 2010 at 1:46 pm


    I know all the AGW guys have rebutted Lomborg in some way or another. I’m not totally convinced by their arguments, but even so am willing to admit they know what they’re talking about. I think I’m unconvinced not because they lack evidence, but again because they have yet to provide a compelling exposition.


    I agree that if they can show my there is an imminent threat that some action should be taken. But with the error bars around most of the impact estimates of global warming I’ve seen, I don’t know that they can make that case.

  17. weingon 22 Jan 2010 at 2:07 pm

    I love global warming, anthropogenic or not. I want more. Of course, I don’t have shoreline property, or live in a south sea paradise. I can see how they would be against it.

  18. Steven Novellaon 22 Jan 2010 at 2:22 pm

    I did not mention the glaciers because Phil Plait just covered that topic extensively: http://blogs.discovermagazine.com/badastronomy/2010/01/21/our-ice-is-disappearing/

    But I guess I should have just linked to it.

  19. zoe237on 22 Jan 2010 at 3:09 pm

    “But there is so much complexity in gathering and assessing this data, that it is unlikely to convince any global warming skeptics. ”

    That’s the problem. There is nothing that will convince (some) of them that AGW is real because of their ideological commitment (mostly to profit/free enterpise). Thus it’s more like pseudoscience, and unfalsifiable.

    As much as I believe AGW is real and a real problem long term, I’m skeptical myself of short term doomsday scenarios. Exagerrating one’s case (in the popular media) also doesn’t do the science any favors.

  20. Jim Shaveron 22 Jan 2010 at 3:19 pm

    Awesome, Steve. I hadn’t read the BA’s blog post from yesterday about the glacial ice. Thanks for the update.

  21. ChrisZon 22 Jan 2010 at 3:20 pm

    As long as we acknowledge that we’re blaming the victim here. The people refusing to entertain certain hypotheses because of their political ideologies, people unwilling to consider experts in the field to be better able to make these claims than they are, people unable to create a logically sound argument or those who refuse to be corrected where their logic fails, these are the people in the wrong. Whether scientists have or have not been as politically savvy as they could have been, and whether that has in any way contributed to lack of acceptance of AGW, it is still the people who have, without good reason, refused to accept a scientific consensus on this topic who are to blame.

  22. johnmatthewsonon 22 Jan 2010 at 3:34 pm

    The best sources that I have found for a quick resume of global warming are:

    The evidence for warming: (2) analysis using source data for global changes


    The evidence for warming: (1) the Himalayas

    The reason I like these is that they don’t stray too much from the data.

  23. superdaveon 22 Jan 2010 at 6:38 pm

    What I find most distressing about this issue is that you can probably predict with at least 75% accuracy which side someone is on based on who they voted for in 2008.

  24. HHCon 22 Jan 2010 at 7:47 pm

    superdave: Both candidates McCain and Obama were supportive of efforts to combat global warming in 2008. The only issue they differed on was Cap and Trade, the establishment of pollution limits and the trading of credits by companies who reduced their emissions to companies that were exceeding pollution limits, as an incentive to get polluters to reduce emissions.

  25. HHCon 22 Jan 2010 at 8:12 pm

    weing, Farmers in Kansas or Nebraska would be against global warming because the increased possibility of drought. The point is that earth’s climate functions best when its in equilibrium.

  26. zoe237on 22 Jan 2010 at 8:37 pm

    Yeah, but McCain lost, and a lot of Republicans didn’t like him. superdave might be right.

    There’s a book called “The Republican War on Science” by Chris Mooney that I enjoyed.

    Of course, that doesn’t mean the average Democrat is thinking scientifically about AGW either.

  27. hmartineauon 22 Jan 2010 at 8:49 pm

    There’s a lot of great information that’s been compiled about the GW/nonGW argument, and a great spreadsheet of resources and data that can be found at http://www.informationisbeautiful.net/visualizations/climate-change-deniers-vs-the-consensus/

  28. weingon 22 Jan 2010 at 9:40 pm


    So I should suffer the cold so that Big Farmer can make a profit? They can always move their farms to areas that will get more rainfall and adapt. We need more accurate models to predict where they should be. Otherwise, this research is a waste of money.

  29. Trevor Mon 22 Jan 2010 at 10:07 pm

    “Extraordinary claims require extraordinary evidence.”

    We are changing the climate of our planet? That is an extraordinary claim. The reason that the climate change movement is floundering is that proponents are not presenting the extraordinary evidence showing that it is man-made. Showing melting glaciers and stranded polar bears does not make the argument that we are contributing significantly to the rise in temperature and that we can do something about it.

    The climate change debate is not supported by logical arguments from those public figures who affirm that it is anthropogenic. It may be true that human activity contributes to global warming. It may be true that we can do something about it. However, the arguments presented are usually based on what can only be viewed as logical fallacies — because they are presented without the hard evidence and the science to back them up. The fallacies from your convienient list http://www.theskepticsguide.org/resources/logicalfallacies.aspx include:

    Post-hoc ergo propter hoc
    Confusing association with causation
    Argument from authority
    Ad ignorantiam

    Even in your piece, Stephen, you rely on The Appeal to Authority fallacy. As you say: “I am content to defer to the consensus of expert opinion.”

    This is a public matter. As public as pandemics and wars. The public is no longer in the 1950’s “science can do no wrong” mindset. They need to see the evidence, the proof. They do not trust that which is not proven beyond “expert opinion” when it costs them tax money and inconveniences them. Expert opinion has been proven wrong many times, and sometimes with dangerous consequences.

    There’s also the problem with what little science is actually being used to make a case to the public. There is no extraordinary evidence of a connection, from what I’ve seen presented to the public. There is no reproducible experiment to test it and confirm it for us all to see. Take a look at the NASA warmest decade data. 1880 to present? So it’s the warmest 1 in 12 or 13 decades by only a tiny amount? Hardly compelling evidence of anthropogenic handywork. The critics of anthropogenic global warming can easily (and rightly) ask about the previous 500 decades. What about the trends in changing temperatures in the past 5000 years of human civilization? They can ask quite rightly if we are truly seeing some kind of big shift. And they’ll want to see proof that we are seeing something out of the oridinary. But then they’ll NEED to see proof that it is anthropogenic.

    Proponents of anthropogenic climate change will usually try and dismiss what we know about 5000 years of constantly fluctuating temperatures. They’ll ignore the question. Also, they will not be able to present any proof that the current trend has anthropogenic roots beyond saying: “I am content to defer to the consensus of expert opinion.” Sorry. That doesn’t cut it as an argument.

    For the debate to effectively end, the argument must be made logically. The evidence of a connection must be made clearly and conclusively for all to see. That just isn’t being done very well and the arguments made are not strong enough on logic. Not be you, either, Stephen. You can do better.

  30. OJBon 22 Jan 2010 at 10:42 pm

    Yes, I think this was a very fair and realistic summary of the subject. There is always doubt in science and climate prediction is just inherently difficult, but I agree that the vast majority of experts agree and all major scientific organisations agree that global warming is real and significantly affected by humans.

    I agree there is some contrary evidence but the majority of people I debate the subject with ignore that and are opposed for political reasons which makes reasonable discussion impossible.

  31. Draalon 23 Jan 2010 at 12:15 am

    A minor point on the number 1.5 Celsius; it appears to be fairly small, and it is, relatively. But if you convert it to Fahrenheit, it’s 2.7 degrees. One issue with the Celsius scale is that the increments are fairly large compared to the accuracy of a simple thermometer can have and what we can feel. It’s very easy to feel the temperature difference between a 77 F day and a 80 F day. So a 1.5 C increase is nothing to sneeze at.

    On a plus side, investment into green technology impacts my field of work directly and may create a job for me in the future. 🙂

  32. whatislogicon 23 Jan 2010 at 9:09 am

    Cats out of the bag on Phil Plait’s buddies over at NASA

    NASA: “Hide this after Jim checks it”


  33. kongstadon 23 Jan 2010 at 9:33 am

    To be fair – freezing in Copenhagen in december is not usual. The average temperature in the daytime for december is 3.7 degrees celsius, nighttime -0.5 degrees.

    Snow in december is also unusual. Actually the average day temoeratures for vinter (dec-feb) are about 2 degrees.

    This winter has been extremely cold, we have hardly had any temperatures above freezing in January, and – very unusually – we have had snow on the ground for most of the month.

    None of this disproves global warming in any way, I just wan’t to counter the idea of Denmark having a sub freezing winter climate. Since the country is so small, and surrounded by water warmed by the guld stream, we have mild winters and mild summers.

    A typical Danish winter is grey and rainy, just like our spring and fall, though we have storms in spring and fall. In summer we generally have light showers and grey weather 😉 Well perhaps not as bad.

  34. fredricwilliamson 23 Jan 2010 at 11:19 am

    While I can hardly disagree with the humility expressed by Mr. Novella, nor can I criticize those who feel the skeptics may be ideologically driven, I think the approach I have used with students who are among the confirmed AGW faithful is to begin by showing them a graph of the temperatures over the past six months — then extrapolating to the next six months as evidence that we will surely freeze to death (if judging in January) or roast (if data ends in July).

    For those who are persuaded by the number and expertise of those in the global warming industry, I point out that roughly 100% of the world’s scientists firmly believed the Earth was the center of the universe. Neither expertise nor numbers are valid evidence of anything.

    That said, I think the evidence suggests that temperatures have risen over the past 100+ years. The figure I think agreed upon a few years ago was around 0.7C. They have also been rising for the past 18,000 years.

    As for glacier-huggers, I grew up in southern Wisconsin, an area which was under a glacier some centuries back. Personally, I have trouble becoming enthusiastic about ice ages as a beneficial climate change.

    And, somewhere back there is someone who wrote that climate equilibrium is best. There is no such thing — the earth was about as warm a thousand years ago as it is now — and that was followed by the “Little Ice Age” which we are still coming out of.

    Remember that scientists get most of their money from politicians, and politicians get most of their power from a good crisis. They may be working together for in the interest of all mankind, or simply pursuing their own interests.

  35. HHCon 23 Jan 2010 at 12:42 pm

    weing, Many farms in Kansas and Nebraska are 500 acres or less, family farms. What you’re suggesting would be likewise beneficial for yourself. Texas needs you! Just move your medical practice to Corpus Christi!

  36. Steven Novellaon 23 Jan 2010 at 3:13 pm

    Fredric – the “scientists were wrong before” argument is not compelling, especially if you have to go back that far. No one is making an argument from authority. Scientific consensus can be wrong, but it is usually built upon logic and evidence, and is a reasonable place to start for a lay person.

    Unless you want to crunch the temperature data yourself from the thousands of stations of decades, you are going to have to trust someone else to do it – someone who’s job it is to do it. When multiple independent analyses come up with the same answer, it is reasonable to take it seriously – not an iron clad, but as reasonably trustworthy.

    The point about scientists getting their funding from politicians is also a weak point. Almost all scientists have to get their money form somewhere, and you can always argue that that biases their research and use that as an excuse to dismiss it. But that’s not enough – you have to show actual bias or fraud, not just make sinister implications.

    And finally – you make one of the very mistakes I pointed out in my post – confusing short term trends with long term trends. Your analogy is not apt.

  37. llewellyon 23 Jan 2010 at 3:43 pm

    mlegoweron 22 Jan 2010 at 1:08 pm :

    Why do I always see charts of the last decade or so when AGW proponents are making their claims?

    The most commonly used charts of global average temperature anomalies are charts which go from 1880 to the present. Like this. I don’t see many of the short term charts you are talking about.
    The polar ice chart Phil Plait recently posted is a great example. 1) It only covers years since 2002 and 2) it graphs the level of changes in polar ice mass, in other words the derivative of the actual mass.
    In this case, the satellites used to measure the ice mass have only been up since 2002. Perhaps Phil should have qualified the limitations of the data he referred to, but the fact that the data only goes back to 2002 is explained in the NASA article Phil linked to. Phil’s post is the exception, not the rule. As a side point glaciers, especially large glaciers, integrate changes in climate over several years, so a few years of ice mass loss does make a statement about slightly longer term changes, which is more than one might assume for the length of time it covers. It’s just not as strong as the aforementioned GISTEMP.

    So I plead with the climate scientists: find a way to graphically depict your evidence which is compelling but not deceptive. It can’t be too hard if the evidence exists, which I truly believe it does.

    The data in question only goes back to 2002. The satellites simply weren’t there before 2002. A longer graph would require making a composite, which is difficult at best, and not always possible to do in a useful way.

  38. llewellyon 23 Jan 2010 at 4:01 pm

    Steven Novella:

    There needs to be more transparency in temperature data and its analysis, not because I think there is any fraud going on, but because we need transparency in order to have public confidence in the science.

    This is true of some climate research institutions, but it is ironic that you bring it up in the context of results from GISTEMP, which made their data, methods, source code, and so forth, widely available several years ago. (Before then, one had to send an email requesting it. Now you just click on a few links.) (I can’t help but bring up that for several years, certain folk would use the CRU temperature record, which shows less warming over the last 10 years, to argue that warming was not happening, and attack GISTEMP because it shows more warming, and then demand more transparency – quite ironic, since it was GISTEMP that was and is open, an CRU, which, while never as obscurantist as it is made out to be, did not release its code, and used data from commercial entities, which made CRU beholden to agreements with commercial entities that refused to allow them to re-distribute said data.)

  39. CWon 23 Jan 2010 at 4:28 pm

    I’ve been doing a lot of reading, and I’m trying to come up with a simple way of discussing this to friends/family that is accurate and fair. What do you think of the following assessment:

    Global Warming/Climate Change: The Steps of Acceptance

    1. The Earth is warming
    2. A warming Earth affects the climate
    3. Climate change is happening due to warming
    4. Man-made activity has some effect on warming
    5. Man-made activity must look at solutions to reducing its effect on warming
    6. Man-made activity has significant effect on warming
    7. Man-made activity must dramatically reduce its effect on warming now

    — Numbers 1, 2, and 3 are fact. (Those who don’t accept these steps, are scientifically ignorant of the issue and climate science and/or ideologically non-objective).
    — Numbers 4, 5 are accepted by nearly all climate scientists.
    — Number 6 seems to have a majority (over 50%) consensus of climate scientists.
    — Number 7 seems to be only accepted by minority (less than 50%) of climate scientists and political ideologues.

  40. weingon 23 Jan 2010 at 5:00 pm


    Your analysis is incomplete. Why is global warming a bad thing and for whom? What are the benefits of global warming and for whom? How much global warming would be good and for whom?

  41. sonicon 23 Jan 2010 at 7:38 pm

    I have spent much time and money supporting conservation efforts. I would like it if we (humans) would get our energy from more sustainable sources.

    The issue of global warming is of interest to me. After much study I have my doubts.

    Here is one example of why-

    Galciers melting does not prove the temperatures are currently getting warmer. It shows that the temperatures in the past (perhaps distant) were cold enough to produce the glaciers. Since that time there has been a warming. But it could be getting colder now and the ice would continue to melt.
    If I got an ice cube out of the refrigerator and brought it into a room that was 80 degrees, it would start melting. If I then turned on the a/c and brought the temperature down to 72, the ice would continue to melt (and would start melting faster and faster as time went).
    Using the ice melt as proof of global warming is not logical.

    Another example-

    We are experiencing the coldest winter on record in many parts of the world. I’m told, “That doesn’t matter, the trend does.” I understand the difference between one year and a trend. My question is this, “Would it matter if this were a warm winter?”

  42. llewellyon 23 Jan 2010 at 9:38 pm

    We are experiencing the coldest winter on record in many parts of the world. I’m told, “That doesn’t matter, the trend does.” I understand the difference between one year and a trend. My question is this, “Would it matter if this were a warm winter?”

    Last time there was an unusually warm winter in the US, climate scientists pointed out again and again that a it is the long term upward trend that shows global warming is real, not a single warm winter. The warm winter, they said, was at most an example. And this year, I don’t see any climate scientists pointing out the ridiculous warmth in Greenland(0) as evidence for global warming.
    But most of the news media is addicted to extremes, either cold or warm, and looking for any excuse to overplay them.
    (0) For about a week, the southern tip of Greenland was about 17 C (30 F) warmer than usual – making it warmer than Florida.

  43. Draalon 23 Jan 2010 at 9:51 pm

    “Why is global warming a bad thing and for whom?”

    George Carlin on Global Warming:


  44. CWon 23 Jan 2010 at 11:26 pm

    @ weing

    Yeah, I’m oversimplifying. But from what I’ve read, it seems to be pretty clear that climate change can have adverse effects on organisms. But you’re probably on to something. Regardless of how climate can change, I wonder if we have sufficient human ingenuity to adapt if needed?

    @ Draal

    I love George Carlin, but regardless of how logical a comedian can sound – I’ll take my science advice from scientists.

  45. Shockstruton 24 Jan 2010 at 1:11 am

    I’d love AGW not to exist. I work in aviation and under any carbon reduction legislation my industry would be right in the firing line. Unfortunately, I think AGW does exist, for the reasons Steve outlined above.

    The problem as I see it isn’t that the climate is going to change overnight in some mass extinction Day After Tomorrow nonsense way. The climate just has to change enough to make feeding six plus billion people more and more difficult to kick the foundations away from under from our civilization.

    So it’s not exactly noble, but the ecosystems can take care of themselves, they’ve had 3.8 billion years of practice. Human society – the only refuge of something other than raw survival – is lucky to have a hundred thousand years on the clock, and a decent way of life for a respectable fraction of the human race is younger than jet engines.

    Deniers – cram it.

  46. sonicon 24 Jan 2010 at 4:24 am

    amazing reading on climate (relevant to the notion that there is a ‘scientific’ consensus here)–


  47. BubbaRichon 24 Jan 2010 at 5:36 am

    A quick Google showed me Tea Party kooks bragging about that site being Lord Monckton’s anti-global-warming website. I just skimmed a few pages from it and noticed great advertising copy with plenty of buzzwords, and only a couple of things I know to be false. I’m too sleepy to do a deeper analysis of it to see who his target audience is, but the types of silly things said in documents like this tend to show that pretty clearly.

  48. whatislogicon 24 Jan 2010 at 10:50 am

    NASA “climate” scientist James Hansen endorses book which calls for ‘ridding the world of Industrial Civilization’.


    Climategate goes American: NOAA, GISS and the mystery of the vanishing weather stations.


  49. HHCon 24 Jan 2010 at 4:04 pm

    Thanks Whatislogic for the connection to San Diego KUSI News programming by John Coleman on another view of global warming, the greenhouse effect, and temperature data set truncation and manipulation.

  50. BubbaRichon 24 Jan 2010 at 5:49 pm

    Are all y’all regular readers of this blog? I feel like I’m slumming on this subject…

    Any appeal to Christopher Monckton or John Coleman is a desperate attempt to say “SEE SOMEBODY LOUD AGREES WITH WHAT I WANT TO BE TRUE!” I’ve read both for a decade, and I don’t recall ever running into a true fact from them. It’s possible they used a couple of true facts, then distorted them out of all recognition using accessory made-up facts. I have never seen anything approaching a serious scientific argument from either of them.

    I’m not an expert in this field, but all of these issues you raise are thoroughly dealt with in the literature. These sources are all of “the hockey stick has been DISPROVEN” school of idiots. It’s like trying to discuss human evolution with somebody who just remembers a picture they once saw of a human riding a triceratops.

  51. whatislogicon 24 Jan 2010 at 6:22 pm

    Today, one of the most powerful religions in the Western World is environmentalism. Environmentalism seems to be the religion of choice for urban atheists. Why do I say it’s a religion? Well, just look at the beliefs. If you look carefully, you see that environmentalism is in fact a perfect 21st century remapping of traditional Judeo-Christian beliefs and myths.

    There’s an initial Eden, a paradise, a state of grace and unity with nature, there’s a fall from grace into a state of pollution as a result of eating from the tree of knowledge, and as a result of our actions there is a judgment day coming for us all. We are all energy sinners, doomed to die, unless we seek salvation, which is now called sustainability. Sustainability is salvation in the church of the environment. Just as organic food is its communion, that pesticide-free wafer that the right people with the right beliefs, imbibe.

    Eden, the fall of man, the loss of grace, the coming doomsday—these are deeply held mythic structures. They are profoundly conservative beliefs. They may even be hard-wired in the brain, for all I know. I certainly don’t want to talk anybody out of them, as I don’t want to talk anybody out of a belief that Jesus Christ is the son of God who rose from the dead. But the reason I don’t want to talk anybody out of these beliefs is that I know that I can’t talk anybody out of them. These are not facts that can be argued. These are issues of faith.

    And so it is, sadly, with environmentalism. Increasingly it seems facts aren’t necessary, because the tenets of environmentalism are all about belief. It’s about whether you are going to be a sinner, or saved. Whether you are going to be one of the people on the side of salvation, or on the side of doom. Whether you are going to be one of us, or one of them.

    -Michael Crichton

    Environmentalism as religion.

  52. BubbaRichon 24 Jan 2010 at 6:32 pm

    This isn’t clear, was Crichton against sustainability? Are you?

    I argue with atheists all the time who argue that, because something is part of a religion, it is ipso facto wrong (and often evil). It sounds like you and Michael Crichton are trying to imply a similar argument. I bet his dinner table was fun, with him pooping in all of the dishes. What, THAT bit of “environmentalism” is good? Are you with the Church or against us?

  53. whatislogicon 24 Jan 2010 at 7:03 pm

    No catastrophe.


    -Michael Crichton

  54. tmac57on 24 Jan 2010 at 7:19 pm

    Re: Michael Crichton’s views.From the appendix of ‘State of Fear’:
    “Crichton’s Personal Views – Where Does the Author Stand? In his appendix, Crichton offers his personal views on climate change. He acknowledges that the world is warming and that atmospheric concentrations of CO2 are increasing, but argues that no one knows how much of the observed warming is due to natural versus human forces. Further, because it is impossible to know exactly how much warming the world will experience a century from now, he argues that his guess is just as credible as the projections from any scientist. By this argument, if my doctor is not 100% certain of his diagnosis of my medical condition, then I’m just as well served by self-diagnosis via random guess.”

    Here is a link to the Pew Center on Global Climate Change, answering some of the questions that Crichton raised in ‘State of Fear’:

  55. whatislogicon 24 Jan 2010 at 7:38 pm

    Crichton as a MD said this:

    What we need is a new organization much closer to the FDA. We need an organization that will be ruthless about acquiring verifiable results, that will fund identical research projects to more than one group, and that will make everybody in this field get honest fast.

    A second method of securing reliable data is one we might call the “FDA Strategy” – a methodology aimed at systematically removing all bias from the process that gives us data we wish to use. I know the FDA is having some troubles at the moment. We can speak of them in a sort of idealized way. The core FDA procedure is the requirement for double-blind studies of drug efficacy.

    Let’s review what a double-blind drug test is. The drug and the placebo are bottled by one group. A second group-that does not know the first-administers the drug to patients. A third group evaluates the patients. A fourth group tabulates the results. None of the groups ever meet. They’re in different cities and preferably different countries.

    We know from experience that this is what we have to do to get bias out of the system. But many areas of research are not held to such rigorous standards. And I can tell you that if there were a double-blind assessment of climate models, the global warming debate would have been over yesterday. I can tell you further that if a blue-ribbon panel of disinterested non-scientists were convened to review the global temperature record, we would also witness a swift end to the current debate. Why? Because at the moment climate science is an insider’s game, and serious outside scrutiny has never taken place.

    I find this inexplicable. We’re talking about spending trillions of dollars to control carbon emissions on a global scale because computer models of climate predict a dangerous future. And yet nobody is willing to subject these climate models to the kind of rigorous testing that we require to license a drug.

    Skeptics like me and Crichton don’t deny climate change we deny the catastrophe the alarmists base off climate models when they cant even predict accurately the weather one week from now.


    RIP M.C.

  56. weingon 24 Jan 2010 at 8:07 pm

    I think we need better and more accurate models. Predicting is very hard, especially about the future. For example, we know the Yellowstone volcano is due to blow any day. Have the models factored in the climate change that will be caused by it?

  57. BubbaRichon 24 Jan 2010 at 9:59 pm

    You need to read more closely, MC actually DOES deny climate change: “And I can tell you that if there were a double-blind assessment of climate models, the global warming debate would have been over yesterday.”

    You also need to read Dr. Novella’s post more clearly: “So let’s dispense with these arguments – there will be short term and local fluctuations in temperatures.” That particular canard about weather forecasts lets me know that you don’t really take this seriously, or you don’t want to understand it.

    My position is almost exactly like Dr. Novella’s, and it’s good to hear it from him since I respect the way he thinks about science and public policy from his podcast. It’s a complex issue, and we have to make complex and potentially expensive decisions based on an imperfect understanding of imperfect information.

  58. Lachlan O'Deaon 24 Jan 2010 at 11:29 pm

    I call myself an AGW sceptic. I haven’t actually run across any sceptics who don’t think the climate is warming. The primary issue of contention is the cause of the warming. Whatever evidence existed to support increased CO2 as a cause has either been overturned by better data (e.g. ice core samples) or found to be fraudulent (tree-ring-based hockey stick graphs).

    But on the point of sceptics arguing about the extent of warming or other climate changes (ice caps, polar bears, etc) – this does occur a lot, even though it’s not the main issue. AGW proponents generally claim that we are seeing climate changes that are unprecedented in history, and therefore there must be an anthropogenic force behind the changes. Sceptics are attempting to put the observed changes into context, in which case they don’t appear anywhere near as extreme. E.g. there are past periods where temperatures have been as high or higher than they are now, such as the Medieval Warm Period.

    I’m actually in favour of developing alternative energy sources to fossil fuels. There are a number of very good arguments for reducing fossil fuel use. But I haven’t seen any evidence to convince me that climactic disaster is imminent and that we must take immediate and drastic action to avert it.

  59. fourelementson 25 Jan 2010 at 3:25 am

    Thanks Dr Novella for a really clear analysis of the climate change debate. It is an issue that has so many facets that it is easy to get tangled up in politics and conspiracy theories, and forget about the science, which in itself is quite complex.

    Personally I think more work needs to be done to better understand climate change, but in the meantime there is suffcient evidence to suggest that we are causing some serious changes to this planet. This shouldn’t be too surprising given that there are now over 6 billion of us – farming, mining, cutting down trees and reproducing. The fundamental principles of the “greenhouse effect” are well understood – carbon dioxide traps heat energy resulting in warming.
    While some dissidents encourage a false dichotomy suggesting that putting funding into reducing carbon dioxide production will cause problems, the development of “green technologies” could have a multitude of benefits for humankind.
    I do have serious doubts about whether the Emission Trading Scheme is going to effect the right sort of change. It seems to me more like an opportunity for bean counters to get rich by shuffling around carbon credits. I would much rather see some sort of carbon tax being used to fund research efforts into better technologies to reduce carbon emissions and to better understand climate change

  60. eiskrystalon 25 Jan 2010 at 5:07 am

    Regardless of how climate can change, I wonder if we have sufficient human ingenuity to adapt if needed?

    No. Not on a large scale. We have neither the time (too late), the resources (our power sources without oil suck), nor the money (we are in debt).

    Moving farming elsewhere implies that the soil at the new location is usable, that we can afford to move, that there is room to farm and the oil available to do so.

    It looks very easy on paper. The devil however is in the details.

    Perhaps Michael Chricton lives on a planet where oil, metals and clean water aren’t running out due to our increasing demands for energy. Perhaps he lives in a magical replenishing world with 4 billion less people than our world and no pollution.

    Michael Chricton it seems, lives in a world where humans don’t have limits forced on them by that nasty environment stuff. He also seems to think that climate change is a drug.

    Strange, strange man.

  61. sonicon 25 Jan 2010 at 5:17 am

    Science and politics and popular passion. Perhaps we need to get fresh eyes on the whole situation (including all data evaluation)


    “The scientist behind the bogus claim in a Nobel Prize-winning UN report that Himalayan glaciers will have melted by 2035 last night admitted it was included purely to put political pressure on world leaders.”

    (BTW- Being good at shooting rockets at targets in space may not be related to being good at predicting the future climate on Earth)

  62. HHCon 25 Jan 2010 at 3:52 pm

    According to NASA TV’s program, “Water for Tea,” 2004, there is a global precipitation project which, if supported worldwide would provide more accurate and quantitative data from earth and space with respect to temperature, precipitation, and the global climate.

  63. tmac57on 25 Jan 2010 at 6:38 pm

    eiskrystal- Michael Crichton doesn’t live on any kind of world anymore, since he died Nov 4th 2008. But yes, he did seem to be disconnected from reality concerning this issue.

  64. BubbaRichon 25 Jan 2010 at 8:18 pm

    Of course, tipping the balance for me with the uncertainties left in the global temperature profile forecasts are the OTHER problems with CO2 in the atmosphere. A best-case solution from the wingnuts often includes the oceans being an even bigger sink for CO2. Of course, the problem with that is that CO2 + H20 -> H2CO3, and it has already led to a -0.1 pH change in the oceans from pre-industrial levels.

  65. Rockheadon 25 Jan 2010 at 9:42 pm

    This was an excellent post. I think the basic problem is that the science is so complicated and multi-faceted, that there’s no single “smoking gun”. It’s also easy to find anomalies that seem at first glance to disprove the hypothesis. But from my reading the climate scientists are trying to do the science correctly; that is, they are making predictions and testing them. They predicted that ice core data would show that CO2 levels and temperature are correlated, and that’s what they found. They predicted that the global temperatures would continue to rise, and so far, that seems to be what’s happening. But what they can’t predict are near-term trends, or local anomalies. They also can’t say with any certainty whether “feedback loops” or “tipping points” will trigger much greater changes than the models predict. Also, they understand that their models have a potentially significant degree of uncertainty. That’s why they attempt to build the uncertainty into the code and run the models in Monte Carlo type simulations.

  66. llewellyon 26 Jan 2010 at 1:45 am

    sonic, please read this reasoned assessment from skepticalscience.com of the IPCC’s mistake, and what it means.

  67. sonicon 27 Jan 2010 at 4:58 am

    interesting read. Thanks

    More problems for IPCC everyday itseems.
    I seems Hansen (NASA) may be a promoter, not a researcher.

    I wish I knew- – I think more and interesting data will be coming out for awhile- I will remain open.

  68. BubbaRichon 28 Jan 2010 at 2:50 am

    Sonic: What on earth does that mean? That’s like saying that Brett Favre is a fan of football, not a player.

    That link was posted here 4 days ago, when it was already a couple of days old, so this doesn’t support your “everyday.” You and uberkook Delingpole don’t seem to notice that what Hansen had nice things to say about was the author’s description of the science, political, and economic implications of global warming. I happen to be against the “post-industrialist civilization” idea of a response to this problem. Of course, if the wingnuts have their way, we might get to that result just by failing to plan.

  69. derwoodon 28 Jan 2010 at 11:45 am

    Trevor M wrote:

    Even in your piece, Stephen, you rely on The Appeal to Authority fallacy. As you say: “I am content to defer to the consensus of expert opinion.”

    This is a misinterpretation/misrepresentation of what the fallacy of the appeal to authority is.

    It is not a fallacy to appeal to ACTUAL authorities on a subject – it is common sense.

    The fallacy part is appealing to a person with IRRELEVANT authority. This fallacy is also referred to as (via Nizkor.org):

    Also Known as: Fallacious Appeal to Authority, Misuse of Authority, Irrelevant Authority, Questionable Authority, Inappropriate Authority, Ad Verecundiam

    Description of Appeal to Authority
    An Appeal to Authority is a fallacy with the following form:

    Person A is (claimed to be) an authority on subject S.
    Person A makes claim C about subject S.
    Therefore, C is true.
    This fallacy is committed when the person in question is not a legitimate authority on the subject. More formally, if person A is not qualified to make reliable claims in subject S, then the argument will be fallacious.

    This sort of reasoning is fallacious when the person in question is not an expert…


    So, a fallacious appeal to authority would be to defer to Ben Stein on evolution or to James Inhofe on climate change.

  70. tmac57on 29 Jan 2010 at 1:35 pm

    derwood, thanks for posting that explanation. I get so tired of commenters misusing the appeal to authority fallacy. Whenever I have called people on this they usually just dig in deeper, and becomes impossible to have a rational exchange.

  71. AGWeirdon 15 Mar 2011 at 8:23 am

    I’ve come up with some thought of my own regarding the anti-AGW arguments.

    According to the following link it is possible to prove that the global warming over the last couple of decades is caused largely by human GHG emissions, by only considering at direct observations we have on the atmosphere and the climate system.

    I think this is a good text, because it’s conclusion is based mostly on direct observations, and not on computer models or indidect indications, so that you can be sure that what you see actually is correct.

    As far as I can see we can summarize the argument created by this text like this:

    Premise 1: If human greenhouse gas emissions affected the climate, we predict the following: 1: the winters to warm faster than the summers. 2: the nights to warm faster than the days. 3: the radiation with the wavelengths CO2 and methane absorb would increasingly be absorbed by CO2 and methane as these concentrations increase, which would increase the amount of radiation reflected back to the earth, and decrease the amount of radiation emitted to space. And so on… (check the link for the rest of the indications)
    Premise 2: We see that the predictions mentioned in premise 1 come true.
    Conclusion: It is very likely that the human greenhouse gas emissions affect the climate.

    I understand that the conclusion is not certain, but cogent. I would consider it a strong argument anyway. I believe this is considered an inductive argument, correct?

    My argument would be similar to the affirming the consequent-argument, which is a logical fallacy. However, I think I fix the problem by not saying that the conclusion is true, only that it is cogent.

    Do you think my argument is valid and sound?
    Would you change or add anything to make my argument better and stronger? Remember that the point is to only rely on direct observations, so that adding supportive evidence such as climate models would be unprefered if possible.

    If I am correct so far, this leads me to the following question:

    Is it true that the only ways to counter a valid argument is to either show that one of the premises are wrong, or by showing that the conclusion does not logically follow the premises?
    Is this true also for inductive arguments?

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