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That study has not been well received in the climate change community. HADCRUT4 is already the de facto standard for land/sea based climate stations/buoys, and

That study has not been well received in the climate change community. HADCRUT4 is already the de facto standard for land/sea based climate stations/buoys, and this does some questionable things with sea water and the land stations. And the HADCRUT4 people wave off the satellite data with "they don't adjust for satellite drift or sensor degradation", but that's all NASA/UAH and RSS do with the data. But even so, their data shows a pause going back 13 years. And this is exactly what I find everywhere when looking for info about the satellite data. Not an explanation of what it means, but attacks on its veracity. Which goes back to my original point or attacking the questioner instead of explaining what the satellite data means. Personally I find it hard to believe that a mishmash of thousands of types of land based weather stations, in thousands of different microclimates and variable conditions, could possible be superior to simply measuring the total energy released by a slice of 75% of the atmosphere.

mikeash 11y ago
I sure hope you're not referring to my posts when you talk about "attacks," because "I don't really know but here's a paper that looks good" is about as far from that as you can get.
- merpnderp 11y ago
  Absolutely not. Sorry for the confusion. I just can't find any papers on why the satellite data is wrong other than hand waving about how peer reviewed research into bias correction is wrong. And I also can't find anything explaining what the satellite data means. That NOAA paper you linked has some interesting issues. But even if it is correct (it's probably not), it shows a low sensitivity to CO2.
  - mikeash 11y ago
    I wasn't sure, so I'm glad I asked instead of assuming! Anyway, I'm afraid I can't really help, I just don't know enough about all the various issues involved. The interpretation of temperature data seems to boil down to a whole bunch of "it's complicated." I lean heavily towards the people who say "it's complicated, but when you analyze it properly it shows warming" over the people who say "the data shows there is no warming" just because the latter tend to see calibration as a ploy and tend not to be well versed in the actual science, whereas the former is usually from people who study this stuff for a living. I will certainly admit that this is not the most solid approach, but it seems to be about the best a person can do without dedicating a significant part of your life to studying it in depth.
    - merpnderp 11y ago
      You are absolutely correct. It is complicated. And given a healthy dose of scientific skepticism, there is no good way to know for sure right now. For instance that NOAA study you linked uses UAH satellite tropospheric data to fill in for missing grounds stations, which is highly controversial (because how does that work), and even more so over the poles, since UAH data their is poor and scattered. Then the .12C difference between ship and buoy sea surface temps seems like is too convenient. I have a feeling that if they were honest with their confidence intervals, they'd be larger than the possible signal. After working through tons of this stuff, reading papers, replicating the math where I can (hard to get source data, and harder to get actual algorithms), I'm left with "who knows?" But the satellite data is clear (and is the only contiguous pole to pole measurement of the atmosphere we have). No warming for over 20 years.
      - mikeash 11y ago
        I'm curious (since it sounds like you've done the work, while I have not), does the trend remain flat if you remove the massive outlier year of 1998? A great deal of the pause seems to be reverting to the previous trendline after a weird spike. But I could be way off!
mturmon 11y ago
If you have not worked extensively with this data (either source), you might not know what its limitations are. The temperature data you mention is a composite from several space-based instruments, that have to be stitched together. Calibration of any space-based measurement is not easy, so your statement "simply measuring the total energy released by a slice of 75% of the atmosphere" is not really that simple at all! In particular, radiometers (like AMSU, where the UAH numbers come from) are really good when used for band ratios (taking the ratio, in essence, can allow instrument sensitivity to cancel out). And they are at their best for short-term studies where instrument temperature and component drift cannot accumulate. But radiometers are not nearly so good at absolute measurements over long time bases. There is a literature on this, for instance: how AMSU temperature drift affects its measurements. In general, I'd suggest that your expertise may not be great enough to dismiss one measurement and favor other, very specific, measurements. Remember that the IPCC contributors have literally devoted half their life to studying these problems. It's hard for an educated enthusiast to keep up. (Source: I work with several IPCC contributors, and their expertise is humbling.)
- merpnderp 11y ago
  Thanks for the kind reasonable response, and yes at some point you have to trust the peer review process on the AMSU bias corrections. But with the UAH 6.0 update, the global data is consistently within .2C of the RSS data, which uses completely different sensors, different teams, and to some degree, different methodologies. Independent verification?
- merpnderp 11y ago
  Given your experience with the IPCC, what do you think of the new NOAA ERSST.v4 contradiction of the NOAA and UK satellite sea surface records? I know the satellite sea surface records are prone to levels of high inaccuracy, but ERSST.v4 seems to contradict every other record. Besides, the idea of getting usable data from sea lanes, of mixed water, from engine intakes seems.....unlikely.
  - mturmon 11y ago
    I feel like there's a lot of armchair scientists playing this like baseball fans, rabbiting after every press release and paper only in the light of what it might say about their already-preferred answer to a rather narrow question. The professionals are trying to advance our measurement and modeling capability, perform calibration and validation, tighten error bars. It's about more than a graph of temperature vs. time.

mikeash 11y ago

I sure hope you're not referring to my posts when you talk about "attacks," because "I don't really know but here's a paper that looks good" is about as far from that as you can get.

merpnderp 11y ago
Absolutely not. Sorry for the confusion. I just can't find any papers on why the satellite data is wrong other than hand waving about how peer reviewed research into bias correction is wrong. And I also can't find anything explaining what the satellite data means. That NOAA paper you linked has some interesting issues. But even if it is correct (it's probably not), it shows a low sensitivity to CO2.
- mikeash 11y ago
  I wasn't sure, so I'm glad I asked instead of assuming! Anyway, I'm afraid I can't really help, I just don't know enough about all the various issues involved. The interpretation of temperature data seems to boil down to a whole bunch of "it's complicated." I lean heavily towards the people who say "it's complicated, but when you analyze it properly it shows warming" over the people who say "the data shows there is no warming" just because the latter tend to see calibration as a ploy and tend not to be well versed in the actual science, whereas the former is usually from people who study this stuff for a living. I will certainly admit that this is not the most solid approach, but it seems to be about the best a person can do without dedicating a significant part of your life to studying it in depth.
  - merpnderp 11y ago
    You are absolutely correct. It is complicated. And given a healthy dose of scientific skepticism, there is no good way to know for sure right now. For instance that NOAA study you linked uses UAH satellite tropospheric data to fill in for missing grounds stations, which is highly controversial (because how does that work), and even more so over the poles, since UAH data their is poor and scattered. Then the .12C difference between ship and buoy sea surface temps seems like is too convenient. I have a feeling that if they were honest with their confidence intervals, they'd be larger than the possible signal. After working through tons of this stuff, reading papers, replicating the math where I can (hard to get source data, and harder to get actual algorithms), I'm left with "who knows?" But the satellite data is clear (and is the only contiguous pole to pole measurement of the atmosphere we have). No warming for over 20 years.
    - mikeash 11y ago
      I'm curious (since it sounds like you've done the work, while I have not), does the trend remain flat if you remove the massive outlier year of 1998? A great deal of the pause seems to be reverting to the previous trendline after a weird spike. But I could be way off!

mturmon 11y ago

If you have not worked extensively with this data (either source), you might not know what its limitations are. The temperature data you mention is a composite from several space-based instruments, that have to be stitched together. Calibration of any space-based measurement is not easy, so your statement "simply measuring the total energy released by a slice of 75% of the atmosphere" is not really that simple at all! In particular, radiometers (like AMSU, where the UAH numbers come from) are really good when used for band ratios (taking the ratio, in essence, can allow instrument sensitivity to cancel out). And they are at their best for short-term studies where instrument temperature and component drift cannot accumulate. But radiometers are not nearly so good at absolute measurements over long time bases. There is a literature on this, for instance: how AMSU temperature drift affects its measurements. In general, I'd suggest that your expertise may not be great enough to dismiss one measurement and favor other, very specific, measurements. Remember that the IPCC contributors have literally devoted half their life to studying these problems. It's hard for an educated enthusiast to keep up. (Source: I work with several IPCC contributors, and their expertise is humbling.)

merpnderp 11y ago
Thanks for the kind reasonable response, and yes at some point you have to trust the peer review process on the AMSU bias corrections. But with the UAH 6.0 update, the global data is consistently within .2C of the RSS data, which uses completely different sensors, different teams, and to some degree, different methodologies. Independent verification?
merpnderp 11y ago
Given your experience with the IPCC, what do you think of the new NOAA ERSST.v4 contradiction of the NOAA and UK satellite sea surface records? I know the satellite sea surface records are prone to levels of high inaccuracy, but ERSST.v4 seems to contradict every other record. Besides, the idea of getting usable data from sea lanes, of mixed water, from engine intakes seems.....unlikely.
- mturmon 11y ago
  I feel like there's a lot of armchair scientists playing this like baseball fans, rabbiting after every press release and paper only in the light of what it might say about their already-preferred answer to a rather narrow question. The professionals are trying to advance our measurement and modeling capability, perform calibration and validation, tighten error bars. It's about more than a graph of temperature vs. time.