On holiday

Tomorrow, I’m off on for a week’s holiday with the family and with some family friends and will probably not have much internet access. I suspect that I will not be writing any posts, responding to comments, or approving any comments. If I get a chance I will, but I may just not be able to do so.

Anyway, today was somewhat interesting as I managed to have a twitter debate with Rupert Darwall about his Spectator article. He seemed to be suggesting that the 10-year smoothed HADCRUT4 temperature anomaly data since 1990 “barely moves”. I assumed he meant a 10-year running average (which is pretty tricky on only 23 years worth of data) and this clearly does not seem flat. Maybe he means something else, so if someone else can clarify, it would be appreciated. Basing your views of global warming on temperature anomaly data alone is rather simplistic, but I’m just interested to know what he means. He didn’t really seem willing to clarify.

I also ended up in another Twitter debate with Richard Tol about his analysis of the Cook et al. paper. I kind of know that I shouldn’t really bother, but sometimes I just can’t seem to stop myself. He seems to think that because he’s made his data and analysis available that it is somehow beyond criticism. I think most of what he’s done is largely meaningless and if he does go ahead and try and get his paper published, I may write another blog post to explain why. As I have remained anonymous I do try very hard to not be personally insulting to those with whom I’m engaging in a discussion. In the case of Richard Tol, though, it is getting harder and harder to resist.

Anyway, I hope everyone has a good week and assuming my enthusiasm for all this blogging remains when I return from holiday, I’ll be back in action in a week or so.

Advertisements
This entry was posted in Uncategorized and tagged , , , , . Bookmark the permalink.

10 Responses to On holiday

  1. BBD says:

    I kind of know that I shouldn’t really bother, but sometimes I just can’t seem to stop myself.

    You can always tell yourself that someone has to do it. Works for me 😉 Enjoy the break. Think not of the blogosphere. Exhale.

  2. Thanks, I plan to make the most of the week away 🙂

  3. Rachel says:

    I don’t know how you do it. Enjoy your holiday.

  4. Skeptikal says:

    He seemed to be suggesting that the 10-year smoothed HADCRUT4 temperature anomaly data since 1990 “barely moves”. I assumed he meant a 10-year running average (which is pretty tricky on only 23 years worth of data) and this clearly does not seem flat. Maybe he means something else, so if someone else can clarify, it would be appreciated.

    The Met Office provides Hadcrut4 in monthly values, annual values and decadally smoothed. They give this description of decadally smoothed on their download page;

    Decadally smoothed series are filtered to remove variability on time scales of less than a decade. These series are computed by application of a 21 point binomial filter to annual time series.

    Hadcrut4 time series is from 1850 to present, so I’m not sure what 23years you’re talking about.

  5. Tom Curtis says:

    Using the HadCRU4 ten year smooth from the link provided by Skeptikal, the trend from 1990 to 2012 is 0.149 C per decade. After initially rising slowly, the smoothed curve rises rapidly from 1993-2004, then declines slowly, with an overall increase of 0.269 C. If that is the data set that Rupert Darwall refers to, his description that it “hardly moves” is far from accurate.

  6. The 23 years referred to 1990 to now (i.e., Rupert Darwall said the decadally smoothed from 1990 “barely moves”).

    Also, as Tom has already pointed out (and what I had already found) is that the decadally smoothed HADCRUT4 data from 1990 to now has a statistically significant trend of 0.149oC per decade (I get the 2σ errors to be 0.0812C per decade) and the overall increase appears to be – again as Tom mentions – around 0.269oC. So, I don’t really understand how Rupert Darwall can claim that it “barely moves”.

  7. Skeptikal says:

    It does seem like an odd claim to make when you look at the data… so much so that I went to your previous post and clicked the link to the met office. No where in the met office article does it mention that he claims; data since 1990 “barely moves”. So I clicked the link in the met office article to have a look at the spectator article which it refers to. The claim is not made in that article either. The only claim he makes is;

    The Met Office doesn’t need a new computer. It needs a new computer model and updated assumptions to replace its HadCM3 model, which builds in an average warming of 0.2˚C a decade in response to rising greenhouse gases. Although emissions have been higher than expected, global temperatures have been flat for 15 years. The Met Office’s own temperature series even shows a small decline since 2006.

    Are you sure the claim was made in this article?

  8. The claim wasn’t made in the article, it was made in a discussion on Twitter (which should have been fairly clear from my post which was discussing the Twitter debate I had with Rupert Darwall).

    Maybe your comment clarifies things. The discussion started with Rupert Darwall saying to Jonthan Leaske Check out decadally smoothed HadCRUT4 since 1990 and tell me what you find, but maybe he was actually referring to the small decline since 2006. I pointed out to him what Tom has pointed out here, but I couldn’t quite got him to clarify what he wanted me to find.

  9. Skeptikal says:

    Okay. I read you had a twitter debate about his article and somehow translated that to being the claim was made in the article and then you were debating it on twitter. I should have realised the claim was made in the twitter exchange when you said “He seemed to be suggesting”.

  10. dbostrom says:

    Well-spotted, Skeptikal. Darwal’s original claim in the article was even worse: “…global temperatures have been flat for 15 years.” Talk about brass.

Comments are closed.