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Lewis vs. Abraham: both are right and wrong

28 Mar

Lewis vs. Abraham

On March 19’th, talk show host Jason Lewis wrote an opinion piece about global warming in the Minneapolis Star Tribune. His headline was entitled “Climate change is natural, and we don’t have the data to predict it”, with the contents reflecting the attitude that climate change isn’t a big deal.

On March 23, engineering professor John Abraham wrote a rebuttal to Lewis’ piece in the same paper. He claimed that Lewis was misleading readers and gave a series of bullet points explaining each error.

Who’s right? Let’s look through the article and keep a running tab of errors. Both articles had errors, and I’ll point them out.

I’m going to quote the section from Lewis’ article, then quote Abraham’s rebuttal, then explain who is right.

Lewis:

The famous “hockey stick” graph showing rapid warming in the 20th century was thoroughly debunked by Canadian researchers even before the purloined e-mails showed how global warming researchers were desperately trying to “hide the decline” in temperatures.

Abraham’s rebuttal:

Made an unsubstantiated and untrue claim that scientists hid a “decline in temperatures.” Where is the evidence of this? No scientists made any statement that they were hiding a decline in temperatures. This is a distortion of a stolen e-mail that was actually referring to increasing temperatures.

Who’s right? Abraham is. “Hide the decline” is NOT referring to temperature. For a better explanation, watch this video.

Lewis 0, Abraham 1.

Lewis:

Not long ago, the Heartland Institute asserted that NASA had “been artificially inflating U.S. temperatures by 0.15 degrees Celsius since the year 2000” and as a result erroneously reported that readings over the last decade “were warmer than the 1930s, when in fact the opposite was true.”

Eventually, agency officials did recant 1998 as the hottest on U.S. record when the data were reanalyzed showing the pre-greenhouse-gas era year of 1934 to be slightly warmer.

Abraham’s rebuttal:

Took aim at reputable institutions, including NASA. He claims that NASA has “erroneously reported that readings over the last decade were warmer than the 1930s, when in fact the opposite was true.” This statement is inaccurate, as is his claim that NASA recanted 1998 as being the hottest year in U.S. history.

Who’s right? They are both right and wrong. The 2000’s were warmer than the 1930’s, in the US and globally. One point for Abraham. However, Lewis’ claim that NASA did have to recant 1998 as the hottest year in the US is true. Abraham is wrong in saying that statement is inaccurate.

If you want proof of this look no further than a 2007 post on RealClimate by Gavin Schmidt, a scientist at NASA:

The net effect of the change [McIntyre’s found error] was to reduce mean US anomalies by about 0.15 ºC for the years 2000-2006. There were some very minor knock on effects in earlier years due to the GISTEMP adjustments for rural vs. urban trends. In the global or hemispheric mean, the differences were imperceptible (since the US is only a small fraction of the global area).

There were however some very minor re-arrangements in the various rankings (see data). Specifically, where 1998 (1.24 ºC anomaly compared to 1951-1980) had previously just beaten out 1934 (1.23 ºC) for the top US year, it now just misses: 1934 1.25ºC vs. 1998 1.23ºC.

Gavin goes on to explain how this isn’t significant. But the point is, Abraham is wrong and Lewis is right. One point for Lewis.

Lewis 1, Abraham 2.

Lewis:

In 1975, Newsweek cited the scientific consensus (heard that one before?) about the coming danger of global cooling.

Temperatures had been declining since 1940 even as carbon dioxide levels rose. Regardless of who is correct, we would do well to remember that cold is far more calamitous for mankind than the purported 0.6 degrees Celsius rise in the last century.

Abraham:

Claimed that temperatures have been declining since 1940. They have not. No scientist would agree with that statement.

Who is right? Well, Abraham is right in stating that no scientist would agree that temperatures have been declining since 1940. But Lewis didn’t say that. He was talking about the 1970’s which is obvious from the context. Had temperatures been declining from the 1940’s to the 70’s? That might depend how you define cooling, but basically yes, Lewis is right.

Lewis 2, Abraham 2.

Lewis:

And therein lies the problem. The global-warming hysteria is based on computer models, not empirical data, because the records simply don’t go back far enough.

If Climategate taught us anything, it’s that these models are subject to human manipulation.

Abraham’s rebuttal:

Alleged that climate change theory is based on models and not real data. This, too, is inaccurate. The fact that increasing greenhouse gases cause the earth to warm is known from data that go back 800,000 years. Is that a long enough record?

Who is right? This is a difficult one. Abraham claims that Lewis is stating that the theory is based on models and not data. But Lewis states that the hysteria is based on models. I think this is true, because I don’t think many people would state that the current temperature of the world demands hysteria. It’s the models which claim that the earth will warm 4 or 5 degrees that we worry about.

However, Lewis claims that we must rely on models because the temperature record doesn’t go far enough back. He might be referring to the instrumental temperature record which only is reliable back to the 1880’s or so. Abraham counters this claim by stating that we have a record of 800,000 years. This is a reference to ice core data. However, Abraham implies that this data proves AGW. Ice core data is hotly contested and to state that the record is proof of AGW is false. It shows a correlation between temperature and CO2, but as we all hopefully know, correlation doesn’t equal causation. There is also a lag versus lead issue, whether CO2 changes the temperature or the temperature changes the CO2 content.

Also, Abraham cannot dismiss the importance models play by simply stating that an ice core record exists. Climate modeling is a huge part of climate science, and it has its own problems.

I’ll call this one a tie.

Lewis:

Across the globe, the last few winters have been exceedingly harsh.

China has endured its most severe winter in 100 years, snow has fallen in Baghdad, and the United Kingdom just suffered through its coldest December since 1683, according to figures from the Met Office.

British astrophysicist David Whitehouse says that not only have temperatures leveled off since 1998, they may actually be cooling once again.

Abraham’s rebuttal:

Suggested that since 1998, temperatures have leveled off and might be decreasing now. It turns out that the hottest three years on record, according to NASA, were 2010, 2005 and 2009. It is tough to have this trend occur in a cooling world.

Who’s right? First, Lewis is citing British astrophysicist David Whitehouse for these claims, which Abraham doesn’t mention. Have world temperatures leveled off since 1998, or even cooled? Well this is a game that is played with starting and ending a trend at different points. It also depends on which record you use. If you start at the height of 1998, and go to right now, temperatures have certainly declined, especially if using the UAH record.

So technically Lewis is right, although Abraham is also right in pointing out that NASA claims 2010, 2005, and 2009 were the three hottest years. Of course those years are only hotter than others by a few hundredths of a degree, and the GISS record doesn’t match up with CRU or UAH exactly.

Phil Jones is famous for stating that there has been no statistically significant warming since 1995. World temperatures haven’t been clearly moving in any direction for over a decade now, and claims of warming or cooling, or hottest year, are just playing around with statistically insignificant numbers and data starting points and ending points.

Neither men get a point for this.

Lewis makes other points but nothing that Abraham challenges. Abraham also makes other claims, such as the following:

Someone reading this article might believe that Lewis knows more about climate science than the 97 percent of scientists who agree that humans are causing the Earth to warm.

Big-time, flat-out wrong. First, he does not make a distinction between climate scientists and all other scientists. Surveys of all scientists have found substantially less than 97% support for AGW.

Even if he had claimed that 97% of climate scientists agreed on AGW, he’d be wrong. That is based on the seriously flawed study Doran 09, or the misquoted study Anderegg 2010. Doran asked questions which nearly everyone would answer yes to (and several prominent “skeptical” climate scientists did exactly that), and Anderegg 2010 only chose certain “top researchers” to get 97%, otherwise it is 66% of researchers who believed AGW.

Well the score ended up tied. What is the tie-breaker?

Lewis is a talk show host. Abraham is an engineering professor at a St. Paul University. Also, he is famous for responding to Monckton of climate skeptic fame on a series of climate issues. One might expect that someone so involved in climate change issues and with a teaching position at a university might understand the issues a little more deeply.

I’m not saying that Lewis gets off the hook for being wrong, only that people automatically value Abraham’s rebuttal more highly because he is a professor instead of a talk show host. It seems clear to me that Abraham is equally as wrong on these issues as a local talk show host.

I won’t declare a winner, it’s more like a loss for everyone who wants to learn more about climate change by reading the Star Tribune.

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2 Comments

Posted by on March 28, 2011 in Uncategorized

 

2 responses to “Lewis vs. Abraham: both are right and wrong

  1. John Abraham

    March 28, 2011 at 8:09 am

    A thorough piece of work and a service to the debate, thanks. I’ll just add a few comments however. First, with respect to models. Jason clearly stated that global warming “hysteria” is based on computer models. Let’s skip what “hysteria” means..that is a value judgement. Let’s just talk about how scientists have evidence of global warming. That evidence is not based solely on computer models. It is based on many lines of evidence. Among them, are, as I mentioned, ice cores. Ice core extractions predict a climate sensitivity of almost the exact same as models. So, if you think models are creating a “hysteria”, then so are ice cores. We also must recognize that there are other paleoclimate records aside from ice cores. There are other lines of evidence as well. Simple radiation calculations show climate sensitivities similar to models. Simple radiative calculations have been made since the 1800s (Svante Arrhenius and John Tyndall). Finally, temperature records since the late 1800s have only reinforced the models. So, you have four lines of evidence (paleoclimate, basic calculations, instrumental records, and models). They are all telling the same story. To say that we are basing our concern on any one of these lines of evidence is simply not true.

    Next, with respect to temperatures since 1998, you cannot be guilty of using the “start-point fallacy” here. Climate scientists look at smoothed temperate trends. Three major institutions that collect global temperature anomalies (Hadley Center, NOAA, and NASA) are all showing temperature records increasing from 1998 until today. You use the interview of Phil Jones by the BBC and it sounds to a reader like Dr. Jones says there has been no warming since 1995. The meaning of “significance” is the critical issue here. I’m attaching the actual question/answer from the interview: You can see that there HAS been warming since 1995, but not significant at the 95% level.

    Question: Do you agree that from 1995 to the present there has been no statistically-significant global warming
    Answer: Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.

    Even if we decide to use the UAH tropospheric temperature data, which is the lowest of the groups measuring tropospheric temperatures, they show a temperature trend of 0.14C/decade. So, technically, Lewis is not right.

    Finally, with respect to 1998 vs, 1934, I communicated with a NASA employee before making my claim and I stand by it. The statement on Realclimate was made but here is is the link with data for the US continental temperatures. I cannot confirm, but I suspect that the statements by Gavin on Realclimate were not accurate. I am looking into this.

    http://data.giss.nasa.gov/gistemp/graphs/Fig.D.txt

    Thanks again for this post, accurate information is critical as we move forward dealing with this challenging problem. I’ll only add that it is important that we can disagree without being disagreeable. While I disagree with Mr. Lewis’ claims and I hope I’ve shown they are largely without merit, I hope my response is taken as it is intended… as a candid but courteous rebuttal.

     
  2. Sam

    March 28, 2011 at 12:27 pm

    Thank you for this response John. You’re quick! As you say, I intend to keep this civil. I really don’t understand all the vitriol.

    Ice core extractions predict a climate sensitivity of almost the exact same as models.

    That’s debatable. This ignores the lead-lag issue and simply assumes the temperature change is solely due to CO2 changes. It requires some unknown mechanism to increase the earth’s temperature for 800 years, and then all of a sudden allow CO2 to take over the driver’s seat. Why? If we don’t know what that originally warming mechanism is, how can we claim the mechanism didn’t play a more prominent role later?

    Simple radiation calculations show climate sensitivities similar to models. Simple radiative calculations have been made since the 1800s (Svante Arrhenius and John Tyndall). Finally, temperature records since the late 1800s have only reinforced the models.

    Radiative calculations generally find a climate sensitivity of 1.2c, not 3c as is the consensus position. That is only reached by using positive feedbacks.

    Finally, temperature records since the late 1800s have only reinforced the models.

    Actually if climate sensitivity were really 3c, then we should have seen significantly MORE warming over the temperature record. This lack of warming is explained by claiming that aerosols counteracted the warming. However I see this as essentially guesswork, there is still substantial uncertainties regarding aerosols and their impact on climate. I’m interested to see if the BEST project will help reduce uncertainties here.

    You use the interview of Phil Jones by the BBC and it sounds to a reader like Dr. Jones says there has been no warming since 1995.

    I clearly state “no statistically significant warming” and my readers are smart enough to understand what that means.

    Phil Jones: I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level.

    This is an important quote. It shows that there has been warming, just not significant warming. Now, I don’t know if you are suggesting we claim the world is warming by using insignificant data, but either way lets look at the implications of this trend.

    0.12c per decade leads to an increase of 1.2c in the next century. This is similar to the increase we have had in the last century, and is substantially less than the IPCC projection. I personally don’t see cause for alarm in this trend.

    So yes, there is warming, but no, it’s not serious. That’s the point.

    Also, one can easily play the start-end game with temperatures. Smoothing takes different forms, and if you look at monthly anomalies the past few months are indeed cooler than most of 1998. The earth has cooled substantially since about Nov 2010.

    How important is this? Long term, it isn’t. It just allows people to make statements about cooling which although technically correct, are misleading. I agree that it doesn’t have much meaning, but the world is cooler today than it was in 1998 and that is the claim.

    Finally, with respect to 1998 vs, 1934, I communicated with a NASA employee before making my claim and I stand by it. The statement on Realclimate was made but here is is the link with data for the US continental temperatures. I cannot confirm, but I suspect that the statements by Gavin on Realclimate were not accurate. I am looking into this.

    Sorry John but even if NASA now has 1998 as warmer than 1934, Lewis is right. He was speaking in the past tense about an event that happened in 2007, read what he said again:

    Eventually, agency officials did recant 1998 as the hottest on U.S. record when the data were reanalyzed showing the pre-greenhouse-gas era year of 1934 to be slightly warmer.

    This happened and is well documented. Look at the following news stories:

    http://www.agiweb.org/geotimes/aug07/article.html?id=WebExtra081607_2.html

    http://articles.latimes.com/2007/aug/15/science/sci-temp15

    http://www.timesonline.co.uk/tol/news/world/us_and_americas/article2271629.ece

    http://www.bloomberg.com/apps/news?pid=newsarchive&sid=aBBQO5XgLQu4

    It happened.

    Since you are responsive to criticism, which I sincerely appreciate, I’d like to end this by bringing up a few issues which I addressed and you have not.

    1. I mentioned that your claim about Lewis stating the world has cooled since 1940 was false.

    2. Your claim about “97 percent of scientists who agree that humans are causing the Earth to warm” does not differentiate between any scientist and climate scientists, which is problematic because polling of all scientists has shown substantially less support than 97%. Also, I’m interested to know if you consider Doran 09 and Anderegg 2010 as valid sources for the “97% of all climate scientists agree on AGW” claim.

    I appreciate your engagement in this discussion, as all too often climate skeptics are ignored. Thank you.

     

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