Climate Sensitivity

34 Years of Satellite Temperature Data Show Global Warming Is on a Plateau


Not so hot?

University of Alabama climatologists John Christy and Roy Spencer have released their monthly statistics on global warming trends detected by National Oceanic and Atmospheric Agency satellites. In the press release accompanying the data, Christy notes that the rise in global average temperatures has been largely stalled since the big El Nino event in 1998:

The lowest level of the global atmosphere has warmed almost one half of a degree Celsius (0.48 C or 0.86 degrees Fahrenheit) during the 34 years since instruments aboard NOAA and NASA satellites started collecting data on global temperatures in late November 1978, according to Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville. While the atmosphere has warmed over the full 34-year time span, it has not warmed noticeably since the major El Niño of 1997-98 — giving us about a decade and a half of generally stable temperatures.

Since 2002, there has been a plateau of relatively warmer temperatures with only 12 months when the global average temperature was cooler than the long-term seasonal norm. In fact, compared to the 30-year temperature baseline, the most recent five years (12/07-11/12) averaged only 0.003 C (0.173 to 0.176 above seasonal norms) warmer than the preceding five years (12/02-11/07). …

The long term 0.14 C per decade warming trend measured by microwave sounding units on a series of satellites is consistent with the low-end of global climate change predictions made by some climate models; it is also within the potential range of natural climate variability, especially since most of the warming happened over such a short period of time.

Based on the empirical data gathered by the NOAA satellites, Christy remains skeptical of climate models that predict future catastrophic warming:

"There are so many natural variations and oscillations that we just can't say that this looks like a human fingerprint on the lower atmosphere's climate," said Christy. "We know that some human activities must have an impact on the climate system. But one has considerable difficulty in looking at what has happened over the past 34 years and reasonably or with scientific accuracy saying whether or by how much the change has been natural or caused by us.

"Changes of this amount over these time scales could be essentially natural. Such a hypothesis has not been proven false. Scientists would love to have these types of measurements from the past 2,000 years to see to what extent Mother Nature can cause changes over decades on her own. But the thorny question of how sensitive the climate is to extra greenhouse gases we are putting into the atmosphere is still up in the air."

In any case, the November global temperature trend update notes:

Global climate trend since Nov. 16, 1978: +0.14 C per decade

November temperatures (preliminary)

Global composite temp.: +0.28 C (about 0.50 degrees Fahrenheit) above 30-year average for November.

Northern Hemisphere: +0.30 C (about 0.54 degrees Fahrenheit) above 30-year average for November.

Southern Hemisphere: +0.26 C (about 0.47 degrees Fahrenheit) above 30-year average for November.

Tropics: +0.17 C (about 0.31 degrees Fahrenheit) above 30-year average for November.

November 2012 satellite temperature trend

Go here to see my October 15 blogpost that looked at what other datasets suggest about global temperature trends and various critiques of those data.

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    1. And we’ll need shithead here to tell us only hillbillies don’t agree with him.

  1. When considering the ‘science’ underlying the AGW scare, I encourage everyone to keep in mind this wonderful lecture by the great physicist Richard Feynman on the scientific method.

    Specifically, listen to his description about how bad science works – talking about psychological studies of the appropriate level of love to show to a child.

    1. The scientific method is no match for the power of CONSENSUS

      1. “People more happily situated, who sometimes hear their opinions disputed, and are not wholly unused to be set right when they are wrong, place the same unbounded reliance only on such of their opinions as are shared by all who surround them, or to whom they habitually defer: for in proportion to a man’s want of confidence in his own solitary judgment, does he usually repose, with implicit trust, on the infallibility of “the world” in general.”

      2. Watching this film of Feynman, I kept thinking he could have easily played a character on The Honeymooners.

      3. The last time we have this much scientific consensus is Eugenics. That really went well.

        1. That’s exactly it. Global Warming is the modern version of Eugenics, pseudoscience pushed by the left to justify totalitarian control

    2. If your theory can’t accurately predict something, it is not science. Feynman was all over fake science and the cult of “experts” who were telling people what they should believe.

      1. If only he were alive today….

        1. One of the things I loved about him is that he had a genuine respect for people who did things. Here was a guy who was a Nobel Prize winner and university professor, an “expert top man” if there ever was one. Yet, he was willing to take the word of the person who had actually been teaching kids for 20 years over the opinion of the credentialed expert. God is that rare today.

          1. The story about the argument he had with a painter about color captures that so nicely:

            Feynman was eating at a diner, and a painter was explaining to a companion or the waitress (I can’t remember) how he made various colors by combining a few paints. His explanation of how he made green paint didn’t make any sense to Feynman, so Feynman starts talking to him and gets very excited, because if the painter is right there’s something wrong with the theories Feynman learned. So he asks for a demo, and the painter starts trying to mix the green, and it’s going badly until the painter says, “I need to add a little blue to sharpen it”, and Feynman says “Aha! You *do* need to mix blue with yellow to get green”.

            He was a great scientist because when someone proved to him that he was wrong about something he was exulted rather than pissed off.

            1. He was a great scientist because when someone proved to him that he was wrong about something he was exulted rather than pissed off.

              If your ability to pay your mortgage hinges upon continuation of a research grant that might get pulled if you fail to prove the need for certain legislation and regulation, then it is understandable that you would be pissed when someone proves you wrong.

              You don’t want to have to look for a real job.

    3. Everyone quotes Richard Feynman. He’s AGW’s most quoted scientist and nobody knows what he thought about it!

      1. He might have thought it was true, who knows. But we do know what he would have thought of the horrible science that is often associated with it.

        1. My position is that the chicanery doesn’t disprove AGW. It just means that we don’t know.

          At this point CAGW is in the almost certainly probably not column. slight AGW is quite possible.

          But, because the proponents of CAGW have crippled good science in order to prevent any chance of their pet theories being falsified, we don’t know what’s going on as well as we could.

          1. My position is that the chicanery doesn’t disprove AGW.

            That’s what is so screwed up about climate “science”.

            The burden of proof is supposed to be on the scientists, not the doubters.

            Making assertions and having a vote does not science make, but that is where we are at with regards to AGW.

          2. Bingo, sarc.

            Its not up to skeptics to disprove the AGW hypotheses.

            Its up to the proponents of those hypotheses to prove them.

            The chicanery isn’t irrelevant; its the whole point of skepticism – to separate the chicanery chaff from the scientific wheat.

        2. This page quotes a good story from “Surely your Joking Mr Feynman”


          I started to say that the idea of distributing everything evenly is based on a theory that there’s only X amount of stuff in the world, that somehow we took it away from the poorer countries in the first place, and therefore we should give it back to them. But this theory doesn’t take into account the real reason for the differences between countries ?that is, the development of new techniques for growing food, the development of machinery to grow food and to do other things, and the fact that all this machinery requires the concentration of capital. It isn’t the stuff, but the power to make the stuff, that is important.

  2. So, over a 34 year time span during which CO2 levels rose pretty consistently year-on-year, temperatures rose for the first 19 years,and then plateaued for the next 15 years.

    Somebody tell me how this data supports any belief that, going forward, additional CO2 emissions will cause higher temperatures?

    I seem to recall that there is a ceiling on CO2’s contribution to the greenhouse effect, that it “saturates” and additional CO2 doesn’t really contribute any more. And that the various computer catastrophic AGW scenarios aren’t so much about more CO2 driving higher temperatures, but about various posited feedback loops that will drive temperatures ever higher. Any reason, now, to believe those feedback loops actually exist?

    1. Somebody tell me how this data supports any belief that, going forward, additional CO2 emissions will cause higher temperatures?

      You’re not applying the proper circular logic.

      First of all, you need some premises:
      Corporations are bad. Big oil is bad. Human activity must be harming the planet because it must. How could it not? Humanity is a disease.

      Now you need some evidence:
      The weather is changing. Temperatures are changing. Storms are affecting people. Some of the storms are really big.

      Use this to form your conclusion:
      Human activity, especially activity that results in certain corporations making profits, is the cause of our changing climate. How could it not?

      1. It really is some version of Original Sin doctrine, only against Gaia in stead of God, and the sin is the activities that support human life instead of self-awareness.

        1. Indeed. A huge portion of the secular-Progressive mindset makes sense if you see it as a disguised expression of the concept of Original Sin.

    2. I seem to recall that there is a ceiling on CO2’s contribution to the greenhouse effect, that it “saturates”

      There is only so much infrared light for CO2 to absorb. Once it is all absorbed, CO2, no matter the concentration, cannot absorb more. How can you absorb more of something that does not exist?

      The doubling people keep talking about is pretty near that “saturation” point.

      Here is a graph:


      1. I should also point out that the models require water to increase in the atmosphere due to warming by CO2…water is also a green house gas and is why the catastrophic AGW folks think it will be catastrophic…

        Of course they run to the same limit of infrared light that CO2 does.

        If CO2 absorbs all the infrared light what the hell is the water vapor going to absorb?

        Anyway studies have found that atmospheric H2O has not increased in modern times…so it is sort of a mute point.

  3. 34 Years of Satellite Temperature Data Show Global Warming Is on a Plateau


    1. Racist!

  4. Christy remains skeptical of climate models that predict future catastrophic warming

    Is he also skeptical of climate models that don’t predict future catastrophic warming? Does he believe that we simply don’t yet know enough but that with enough information and knowledge humans will someday be able to know the future? Or does he believe that something as complex as the planet’s climate might contain enough random events that nobody can say with any certainty what the future holds? (And what effect *will* the Yellowstone super-volcanic eruption have on the climate?)

    1. Re: Jerryskids,

      Is he also skeptical of climate models that don’t predict future catastrophic warming?

      So far, the evidence is against the models that predict future catastrophic warming, so it makes sense to be skeptical of those.

    2. Does he believe that we simply don’t yet know enough but that with enough information and knowledge humans will someday be able to know the future?

      This belief (or lack of it) is irrelevant to being skeptical of current climate models.

  5. The 34 year trend seems like it might be significant until you consider that it’s a mere fraction of a percent of the total time Earth has even been around to have a climate: six thousand years.

    1. And the first seven days of those 6,000 years were God-days so who knows how long they really lasted.

      1. By that of course you mean that they lasted exactly seven days, right?

  6. Just by looking at it, it’s a very tough dataset to make heads or tails out of. It obviously looks like ‘up’ but how much and the shape of the curve is very difficult to ascertain from that data. And so it really is a case of trying to control for outside variables, and for something like climate the potential list of those is endless.

    Though climate is light years from my field, I think it would be a fascinating field to work in statistically, except that I think I’d have a general fear that I’d wind up in trouble if I came up with a model that said the ‘wrong’ things.

    And that’s a bad atmosphere for good science. Folks need to desperately dial back the vitriol and rhetoric on this thing and let folks follow the data. Of course the chances of that happening are…

    1. And that’s a bad atmosphere for good science.

      Greenhouse gases are now impacting science’s atmosphere! Where will it end?

  7. That’s nice and all, but this is pretty old news.

    1. Sort of.

      The 16 years of no warming you heard about a couple of months ago comes from the Met office and the CRU. Which get their data from surface temperature stations.

      John Christy and Roy Spencer gets their data from satellites and are independently confirming there has been no warming for 16 years.

  8. Glad to see the ‘sine wave’ curve (I think it was a 5th order polynomial or some such nonsense) off of there. That thing made zero sense to me.

    Though I think a fitted exponential curve might be something worth looking at. Not ‘proof’ of much of anything but an interesting visual if nothing else.

    1. Even a (much) longer moving average would be nice.

      The sine wave was just a thought, anyway, as I recall. It was kind of an interesting loose fit until the last few years. When the data quite fitting, he dropped it.

      If only everyone would do that.

      1. I actually found the data from an earlier post, and did a quick fit and does look like the slope of the line would go up slightly each year (IE, the best fit exponential curve is concave up), which means the rate of warming would be increasing. But that’s treating all data points as equal. Treating more recent data points as more sensitive would probably change that.

        Anyway the difference between that and strict linear and one that goes concave down is trivial, and certainly no conclusions at all could be reached with such limited data.

  9. Air temperature data is the most prone to noise of all the climate metrics, so its no surprise the authors are hesitant to make any conclusions. It’s like if a doctor judged your health by smelling your breath … the natural variability argument will never go away, but its not the long-term, low frequency cycles we need to worry about (i.e., oscillations in solar output, axis wobble, sea temps, cosmic radiation, etc …) regardless of how dominant they appear to be; rather, its the short-term, high-frequency events of increasing severity by our own doing (i.e., repeatedly overdrawing aquafers, cutting down forests, chemically sabotaging the soil, casually inducing the next mass extinction in the hunt for infinite growth, & burning all that carbon we found in the earth’s deep storage) that should be the cause of concern. The former are quite regular and will continue to be so no matter what we do while the latter is, at best, an invitation for global conflict. Hopefully, the blatant turn towards fascism is an indication the overlords are losing their grip.

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