“Not Up for Debate?”

I was pointed to this debate between Ted Cruz and Sierra Club President Aaron Mair by my Uncle Rocco Russo II. He asked me to comment, so I will.

Completely up front : Mair’s performance was not flattering. He was unprepared to answer the questions and his team was only marginally better, and they simply moved very quickly to an appeal to authority about the science. Of course, it is somewhat because Cruz’s questioning is a red herring, so he is forgiven for the simple appeal to authority.

Here is the argument without the appeal to authority : Data are data. You can’t fake it. However, it’s also hard to analyze. Here are a few facts.

“Not up for debate?”

Cruz asks if the question of global warming is not up for debate. Firstly, let’s realize what this is : a Congressional hearing. It’s not a scientific platform. There is a vast difference between a scientific debate and a Congressional “debate” (quotes on purpose).
In a scientific debate, we take observable data, develop hypotheses, and test them. The bad ones (i.e. the ones that do not agree with reality) are discarded. The good ones are tested against other observable data.

In a Congressional “debate”, people’s primary objective is to get re-elected. Hence, the quotations around “debate”. There is usually no actual debate, merely stating talking points again and again, usually put in their mouths wrapped in cash by special interest groups.

The difference lies in how one deals with falsification of hypotheses. Scientists discard falsified hypotheses, whereas Congress will not change their minds based on evidence. That isn’t a scientific debate, it’s a talking point.

I have actually personally (myself, with my own hands) analyzed global warming data. The trend is completely clear : we are getting hotter, and the only question is not IF something bad will happen, but only HOW BAD it is (choices are “bad”, “really bad”, and “really REALLY bad”) and WHEN it will happen (choices are “within 40 years”, “within 100 years”, and “within 300 years”). 

Regarding global warming data

The scientific debate over the general idea is effectively over. There is broad consensus (i.e. >90% of scientists agree) that

  1. global warming is occurring,
  2. humans are contributing to it, and
  3. c) extremely bad things can happen in the very near future if we do not change our habits.

“Do you know “The Pause””

Cruz asks Mair if he knows about “The Pause” (not the band, the thing). This is also known as “The Hiatus”.

“Computer models say there should be dramatic warming, but the actual satellites taking the measurements don’t show any significant warming”.

Here is a plot of the data in question :

Global temperature anomaly from http://data.giss.nasa.gov/gistemp/

Here are the data directly :

http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.txt

Sen. Cruz’s conclusion is factually untrue. Year-to-year variations are approximately 0.1 C at the 95% confidence level, so that means the uncertainty is 0.05 at 68% confidence level (I use the latter in my statistical analysis). Given the period from 2000-2015, compared to the previous trend from 1960-2000, the current deficit this is well within the expected year-to-year statistical uncertainty of the dataset. Furthermore, after correcting for other known systematic effects, the measured temperature is actually higher than the raw data by about 0.1 C. This lowers the discrepancy between the two periods.

Nevertheless, I performed my own quick analysis of this dataset.

Data from http://data.giss.nasa.gov/gistemp/
Data from
http://data.giss.nasa.gov/gistemp/

If we break up the dataset into 1960-2000 and 2000-2015, and assume a simple linear relationship in both, what you actually see is that there was a JUMP in the late 1990’s. The data then fluctuated back to the average in 2000-2015, as evidenced by my plot. The red line is the 40-year trend from 1960-2000. The dashed red line is the extrapolation to 2015 assuming the same trend. The blue line is the trend from 2000-2015. As you can see, currently we are HIGHER than a simple continuation of the trend from 1960 to 2015.

Cruz is referring to the difference between the slopes of the blue and red lines and saying “Look! We’re getting better!” However, this is completely the wrong conclusion based on the data analytics. This is an illusion of an improvement due to an UPWARD FLUCTUATION in the temperature followed by several years that were closer to the previous trend. That is, we simply didn’t get worse as fast in 2000-2015 as we did in the late 1990’s, but it was already much worse than expected before. We’re still heating the earth at a rate of about 1 C per century. 

Harvard educated University at Buffalo professor : 1

Harvard educated Texas Senator : 0

If you’re interested, here are my fits :

1960-2000 :
Chi2                      =      160.824
NDf                       =           38
intercept                        =     -29.2051   +/-   1.35606
slope                        =    0.0148396   +/-   0.000684867

2000-2014
Chi2                      =      14.0635
NDf                       =           12
intercept                        =      -15.199   +/-   6.65315
slope                        =   0.00789011   +/-   0.00331497

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2 thoughts on ““Not Up for Debate?”

  1. Sal, you are packaging arguments in a way that strongly suggests an attempt at manipulating the audience. Do you not find it dishonest and misleading?

    Here is an example, quote:

    > Regarding global warming data
    >
    > The scientific debate over the general idea is effectively over. There is broad consensus (i.e. >90% of
    > scientists agree) that
    >
    > 1. global warming is occurring,
    > 2. humans are contributing to it, and
    > 3. c) extremely bad things can happen in the very near future if we do not change our habits.

    The trick here is that you packaged the three points such that even skeptics (I am being one), if they are honest, have to agree with the letter of what you wrote while many of them actually disagree with the spirit of it, especially in #3. That is because all sense of likelihood and scale is omitted from #3. Anything can happen any time but how likely is it, what are the alternatives, how bad is it, and what is the utility for us? I actually agree with #1, and I would make #2 even stronger, I believe that human role is defining but #3 is grossly useless and misleading.

    Let me rewrite this excerpt applied to a different scenario.

    Regarding meteorite data

    1. meteorite hits to the Earth are occurring
    2. humans are contributing to it (by putting things into space and them falling back on Earth)
    3. extremely bad things can happen in the very near future if we do not change our habits.

    What I wrote is obvious nonsense. It is also literally true, and 100% of the honest scientists ought to agree with that.

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  2. I am not trying to manipulate anyone, Gena, and not being dishonest nor misleading.

    My statement was true : Over 90% of scientists do agree with the letter AND the spirit of my post. Over 90% are concerned with global warming and are in favor of policies lowering emissions. Now, you agree with #1 and #2, and even the face-value of #3. I would say you are basically okay with the scenario of “bad things happening”, but not “really bad” or “really REALLY bad”. There is no debate that rising sea levels is bad, but is it something we should actively try to change? That is certainly open to discussion.

    However, the “debate” (quotes intended) happening in Congress is not whether #3 is happening, or even whether the scenarios are “bad”, “really bad”, or “really REALLY bad”, but instead they are arguing against #2 and even #1. In this case, Cruz is literally making the argument that the earth is not actually warming in the last 15 years and that therefore “global warming is wrong”. So you disagree with Cruz, and I disagree with Cruz, and you and I agree on #1 and #2, and even #3, but not whether or not we need to adjust our behavior. I’m happy to continue that debate, but it’s not the one that’s happening in Congress.

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