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You've made two complaints that I can't reconcile with one another. (1) That it was discovered that the data from ground weather stations were a mess. (2) That it's terribly suspicious that between 1999 and 2019 NASA's estimates of historical temperature changed. Of these, #1 sounds very plausible, and precisely for that reason #2 seems entirely wrong. I don't mean that the specific changes you're pointing at are necessarily about fixing #1. I mean that pointing out #1 shows that you are aware that our best estimate of something in the past can change as we discover more, correct errors, understand things better, etc. Which means that "look, the historical estimate from 1999 differs from the historical estimate from 2019" really isn't any sort of gotcha. Unless you have actual evidence that the changes were the result of something other than better data and/or analysis. (Also, that pair of graphs can't possibly be an example of changing historical data to get rid of a hiatus starting in 1998, for obvious reasons.) I think you have misunderstood in multiple ways what I was saying about the "hiatus" starting in 1998. Firstly, I was not claiming that only the "unorthodox" mentioned it. I was claiming that the "unorthodox" represented it as showing that global warming had stopped and the "orthodox" said otherwise. Your pair of Nature links are of "orthodox" climatologists saying things along the lines of "here is what we think may be the reason why the last few years haven't seen a short-term increase; the underlying trend is still upward": in other words, they are examples of the orthodox saying what I said they said. Secondly, perhaps what I said about "signal" and "noise" gave the impression that I think, or think that "orthodox" climatologists thought, that the "noise" is measurement error. That's not what I meant at all, and I apologize for not being clearer. The point is that the temperature at any given place and time is a combination of lots of factors; some operate on a timescale of decades (global warming due to rising CO2 levels and all that), some on a timescale of multiple years (El Niño), some on much shorter timescales still ("random" variation because the atmosphere is a chaotic system). However accurately you measure, you're still seeing this sort of combination of things, and a time series lasting (say) 10 years will not necessarily reflect what's happening on longer timescales. The 15 years starting in 1998, viewed in isolation, really do show a slower warming trend than the claimed long-term behaviour. There's nothing unreal about that, and so far as I know "orthodox" climatologists never said otherwise. What they said, and continue to say, and what I am saying, is that this sort of local counter-trend variation is perfectly normal, is exactly what you should expect to see even if global warming is proceeding exactly the way that orthodox climatologists say it is, and is not grounds for making claims that global warming has/had stopped or never been real in the first place. The "everything changes" article you quote isn't saying what you're trying to make it out to be saying. (You can find the PDF here: https://www.researchgate.net/profile/Tr-Karl/publication/277... .) The authors have done two things. First, some corrections to historical data. (If you look at the graph at the end of the article you'll see that these corrections are pretty small. Their description of what they changed and why sounds perfectly reasonable to me; if you have good reason to think it's bogus other than the fact that you liked the old version better, do by all means share it.) Second, including more recent data. 2013 and, more so, 2014 were pretty warm years. But what makes me think that the "unorthodox" were wrong to proclaim the end of global warming in the early 21st century isn't tiny adjustments in the data that make the difference between a +0.03 degC/decade trend between 1998 and 2012 and a +0.11 degC/decade trend between 2000 and 2014. It's the fact that after that period the short-term trend gets much faster, exactly as you would expect if the "hiatus" was simply the result of superimposing short-term fluctuations on a long-term trend that never went away. I bet you are not 100% wrong about the tendency to adjust things to try to correct perceived anomalies. That's human nature, and while scientific practice has a bunch of safeguards to try to make it harder to do it would be surprising if they worked perfectly. But note that the sort of small local tweakage this might produce can't do much in the long term. Let's suppose those people writing in 2015 were completely wrong to make the adjustments they did, whether out of dishonesty or honest error (which maybe they were more inclined to overlook because the adjusted data looked more plausible to them). Then, yeah, they get a faster rate of warming between 1998 and 2014. But those same adjustments will produce a slower rate of warming between, say, 2014 and 2024 when someone comes to estimate that. And the rate of warming between 1998 and 2024 will scarcely be affected at all by tweaks to the numbers circa 2010. Your last paragraph is (at least as far as I'm concerned) completely wrong, though. I think it was perfectly reasonable to say that the warming trend between 1998 and say 2012 was much slower than the alleged longer-term trend. What I think wasn't reasonable, and what I think has been refuted by later data, and what the "orthodox" climatologists said was wrong all along, was claiming that that short-term slower trend meant that the longer-term trend had gone away, or had never really been there in the first place. That was just statistical illiteracy, and Team Unorthodox were pretty keen on it, and that doesn't speak well for their competence and honesty. |