Dedicated to the balanced discussion of global warming
carbon offset / trading greenhouse kyoto climate model Inconvenient Truth bio fuel ipcc Glacier

Powerline graphs – how about some background?

Powerline is a very popular blog and forum for those that follow a conservative movement within the US. I am sure that their membership measure many multiples over this site.  Therefore, I am hesitant to be too condemning of one of their recent posts but I need to talk about it a little bit.

To their credit, they encourage readers to go to the original sources to get the complete story but, frankly, that is not good enough.  They have published the information in a way that is incredibly one-sided and is also not consistent from one chart to the next.  That is the true problem with the article, one cannot see the filters or data sources in this presentation so the inconsistencies are too strong.

The first chart tries to show temperature swings of the last 12,000 years.  The problem is that none of these previous highs (save one) show the temperature increasing, leveling off, and then increasing again.  This is absolutely the situation in the latest bump above the line which implies that something may be different in this latest warming trend.  Of course that difference could be the ways that the temperatures are gathered (with satellites today v. observing tree rings or other such proxies).

The second chart tries to ridicule the IPCC projections which are based on computer models (I give little credence to most computer models as regular readers know).  However, did they bother to look at the major inconsistincies with the chart immediately above?  The first chart is a straight line average starting and stopping at 15 degrees and the second is consistently increasing.  What are the differences and why?  While more in depth reading of both studies would likely give a clue as to the differences, showing both charts side-by-side raises huge skepticism in the quality of the data.

Also, why does the 2nd chart imply that historical average temperature was crossed at about 1960 but the first chart implies that it happened a few hundred years ago?

Then the 3rd chart shows temperature going down but that disagrees with the first chart where the final trend was going up and the second chart which has the average increasing on a regular pace.  What gives?


I could go on and on but I think you have seen the point.  The article stops being about the science that they rave about in the beginning of the piece and gravitates to a consistent whine that the IPCC is not fair and the US government administration should run away from its intended policies of climate crisis control.

I hope that future discussions of this are more about science and data.  Let the conclusions come without filtering for agenda and political goals.  It is frustrating to follow this topic so closely on this site only to be at the same basic point we were at when I first started this discussion.  We simply need to let the science figure this out and THEN we can prescribe the medecine for what ails us.  We cannot all agree if we have a cold, the flu, tuberculosis or liver cancer yet!  But I do know all of this political maneuvering is giving me a headache.

I think I will just go take 2 aspirin and see if I feel better tomorrow.

, , ,

Similar articles that you may enjoy:

7 Responses to “Powerline graphs – how about some background?”

  1. I sometimes read Powerline (though not as often as I used to). They’re smart guys, but they’re not scientists.

    I give them about as much credit as I give me–I trust myself to have sufficient grasp of logic to tell when alternative explanations have been considered, when the explanation of the data supports the conclusion asserted, when the limits of the data have been respected (IMO, the biggest failing of the AGW media), and I am comfortable with the settings on my BS indicator.

    I do not, however, trust myself to collect, analyze or do initial interpretations on raw data. For that I need to rely on others. Who to trust is a huge and difficult question, but it is not the Powerline guys.

  2. Great point Tim on not sure who to trust on interpretation of data. I can usually figure out when a hack is interpreting data and screwing it up but if someone is really smart and they want to deceive me, it can be done.

    Kind of like locking your car on the street. You know that a real pro will get it if they want to steal it but local rowdies will likely not borrow your car for a joy ride if the doors are locked and the key is not in the ignition.

  3. I am surprised at your comment:

    > “Also, why does the 2nd chart imply that historical
    > average temperature was crossed at about 1960 but
    > the first chart implies that it happened a few hundred
    > years ago?”

    Have you ever looked at long term and short term stock graphs? They all show ups and downs and have their own overall trend lines.

    The 2nd chart is a short term showing how on a decadal level, temprature oscilates and shows the period covering the rise out of the Little Ice Age, so it shows an overall up trend as is correct for the period of 200 years shown.

    The 1st graph shows that on a millenia level temprature oscilates too. The oscilations in the 1st graph would simply be noise on the LAST up-trend shown on the 2nd graph coming out of the little ice age, just like the ups and downs of short term stock graphs are noise on long term graphs.

    Both graphs are correct and not inconsistent at all.

  4. In the last para of my post I mixed the graphs and referenced them backwards. It should read:

    The 1st graph shows that on a millenia level temprature oscilates too. The oscilations in the 2ND graph would simply be noise on the LAST up-trend shown on the 1ST graph coming out of the little ice age, just like the ups and downs of short term stock graphs are noise on long term graphs.

    Both graphs are correct and not inconsistent at all.

  5. As for your question about the last graph, you can’t compare it to the first graph as the first is a millenia graph and so shows what’s going on a different timescale – as expalined above.

    As for the 3rd graph compared to the 2nd graph, First of all, the 2nd graph shows the temprature oscilations relative to the trend line which has been rising since the 1800s, as is correct if you look at the 1st graph from the 1800s. Second of all, the 3rd graph is only from 1980 and shows the oscilations relative to the same trend line of the 2nd graph, it’s just that the trend line is shown flat coz the 3rd graph is just showing relative changes and not the actual trend.

    If you turn the second graph so the trend line is flat and just compare the portion from 1980, you see it has the same basic shape as the 3rd graph.

    I’m surprised people don’t understand how to read graphs. Don’t they teach that in high-schools in the US??

  6. […] Climate Change Global warming is a natural phenomenon, records in the ice cores show that over millenia the Earth has warmed and cooled. Whether this was down to some change in the solar system I don’t know but the fluctuation […]

  7. QUOTE: “The problem is that none of these previous highs (save one) show the temperature increasing, leveling off, and then increasing again.”

    And your point is? First, the graph is not very detailed – so in fact it is most likely the case that there have been other cases of “increasing, leveling off and then increasing again”. Second, even if there were not, doesn’t matter. It did happen once before, clearly. Third, you have to remember, the data from which paleoclimate “guesses” are constructed are not necessarily without significant sources of error. And finally, according to the warmists, there was no Holocene Optimum or Little Ice Age so what are you doing presenting them as part of your spiel?

    Seriously, keep up the good work and spend less time making negative comments about other people and their sites. It tends to make you look smaller, not them.