tag:blogger.com,1999:blog-9959776.post1255149144989394034..comments2024-02-15T04:42:41.606+00:00Comments on James' Empty Blog: Decadal prediction cage fightJames Annanhttp://www.blogger.com/profile/04318741813895533700noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-9959776.post-90744080635620553162009-02-26T03:06:00.000+00:002009-02-26T03:06:00.000+00:00Steve Bloom, James Annan:A link to the complete re...Steve Bloom, James Annan:<BR/><BR/>A <A HREF="http://www.jser.gr.jp/index.html" REL="nofollow">link</A> to the complete report in the original Japanese.bi -- International Journal of Inactivismhttps://www.blogger.com/profile/03030282249404084578noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-3864989627546707932009-02-25T23:20:00.000+00:002009-02-25T23:20:00.000+00:00James, I assume that by now you've seen this artic...James, I assume that by now you've seen this <A HREF="http://www.theregister.co.uk/2009/02/25/jstor_climate_report_translation/" REL="nofollow">article</A>. If the translation is accurate, your concerns about management would seem to be confirmed. Any details you could provide on this report would be appreciated.Steve Bloomhttps://www.blogger.com/profile/12943109973917998380noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-89259758459081085712009-02-25T20:03:00.000+00:002009-02-25T20:03:00.000+00:00Asked and answered elsewhere (dozens of places). ...Asked and answered elsewhere (dozens of places). One was<BR/>http://tamino.wordpress.com/2008/11/23/open-thread-8/#comment-24387Hank Robertshttps://www.blogger.com/profile/07521410755553979665noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-47863375282656150172009-02-25T19:37:00.000+00:002009-02-25T19:37:00.000+00:00The transport of aerosols in the atmosphere is a c...<I> The transport of aerosols in the atmosphere is a complex process - if they get into the free troposphere, their lifetime is 1-2 weeks, and during that time, they can travel long distances, such as China to Europe, or Africa to America. Sure, their climatic effects are mostly "regionally specific", but there are exceptions. Google "arctic haze".</I><BR/><BR/>Totally agree with all you've written. But te net effect of "arctic haze" is one of <B> warming </B>. My point still stands, i.e. aerosols cannot explain the 1940-70 arctic cooling and CO2 (or solar) cannot <BR/>explain the 1910-1940 arctic warming.John Finnhttps://www.blogger.com/profile/06614613390849062784noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-62657644305183967852009-02-25T18:30:00.000+00:002009-02-25T18:30:00.000+00:00John,The transport of aerosols in the atmosphere i...John,<BR/><BR/>The transport of aerosols in the atmosphere is a complex process - if they get into the free troposphere, their lifetime is 1-2 weeks, and during that time, they can travel long distances, such as China to Europe, or Africa to America. Sure, their climatic effects are mostly "regionally specific", but there are exceptions. Google "arctic haze".Adderhttps://www.blogger.com/profile/02450247722901349068noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-16005733112050153632009-02-25T10:02:00.000+00:002009-02-25T10:02:00.000+00:00I don't think it is necessary to explain every wig...<I>I don't think it is necessary to explain every wiggle in terms of deterministic factors - there is undoubtedly some natural variability in there too (in increasing amounts as we look at smaller areas) Eg, I believe there was a big El Nino around the 1940 peak. But there's a big volcano in 62-63, and a small drop in solar forcing after ~1945 too, to add to the aerosol forcing </I><BR/><BR/>No, James, that does not explain why the Arctic warmed 2 deg between 1910 and 1940 and cooled a degree between 1940 and 1970. There are not wiggles they are sustained long term climate shifts which are, far and away, the biggest contributors to climate change over the past century. <BR/><BR/><I> Of course all the models include the ocean! </I><BR/><BR/>Ok. Yes, James, I know all the models "include the ocean". It's a bit disappointing you've reverted to the usual tactic (on both sides) of deliberately misinterpreting my point. <BR/><BR/>You graphic is effectively the result of a "detection and attribution" exercise. It attempts to explain warming (and cooling) over the past century by various forcings. But it doesn't make sense. <BR/><BR/>QUESTION: If industrial aerosols are responsible for the mid 20th century cooling - why is it that the Arctic cooled at 4 times the rate of the NH in general. <BR/><BR/>Perhaps Hank can answer the question .... I can waitJohn Finnhttps://www.blogger.com/profile/06614613390849062784noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-78149227974170169122009-02-25T05:32:00.000+00:002009-02-25T05:32:00.000+00:00It's clear from this new paper that teasing out th...It's clear from this new <A HREF="http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo437.html" REL="nofollow">paper</A> that teasing out the specific effect of aerosols isn't entirely simple even when good obs are available. Re the Arctic, IIRC some work has been done pinning at least part of the early 20th-century warming to industrial soot.Steve Bloomhttps://www.blogger.com/profile/12943109973917998380noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-22946054370354100272009-02-25T04:37:00.000+00:002009-02-25T04:37:00.000+00:00no problem Hank - but it does explain things :-)Jo...no problem Hank - but it does explain things :-)<BR/><BR/>John,<BR/><BR/>I don't think it is necessary to explain every wiggle in terms of deterministic factors - there is undoubtedly some natural variability in there too (in increasing amounts as we look at smaller areas). Eg, I believe there was a big El Nino around the 1940 peak. But there's a big volcano in 62-63, and a small drop in solar forcing after ~1945 too, to add to the aerosol forcing.<BR/><BR/>Of course all the models include the ocean!James Annanhttps://www.blogger.com/profile/04318741813895533700noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-17203668937313808372009-02-24T16:34:00.000+00:002009-02-24T16:34:00.000+00:00Sorry, James, I mentioned the thread at Tamino's y...Sorry, James, I mentioned the thread at Tamino's yesterday. My bad.Hank Robertshttps://www.blogger.com/profile/07521410755553979665noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-71404136869053582162009-02-24T11:26:00.000+00:002009-02-24T11:26:00.000+00:00James Looking at the graphic it would seem that, a...James <BR/><BR/>Looking at the graphic it would seem that, according to the model, solar + ghg are the major factors which contribute to the early 20th century warming and that the increase in sulphate (industrial)aerosols is the factor which not only halted the warming trend but actually reversed it. <BR/><BR/>I have to say I have some doubts about this, industrial aerosols, unlike CO2, are short-lived in the atmosphere and do not build up over time. There would need to be a massive and constant increase to produce the claimed effect. But that's not all. <BR/><BR/>Because of the short residence time, the climatic effect of aerosols will be most pronounced over the regions from which the aerosols originate. Mike Mann and Phil Jones published a paper in ~2003 which stated that the effect of aerosols is <B>"regionally specific"</B>. So, the areas that should have experienced the greatest cooling in te post-1940 period are the industrialised regions in the US and W. Europe. But that's not what happpened. <BR/><BR/>The region which experienced the largest (by far) drop in temperatures was the ... the Arctic. <BR/><BR/>According to the GISS zonal data record, the Arctic (64N-90N) cooled almost 1 deg C or about 4 times as much as the indusrialised mid-latitiude regions - and about 3times the rate of my home city in the UK midlands. I'm not sure if you're originally from the UK, James, but if you are you'll know that during the 1950s, 60s and 70s, the midlands was one of the most intensely industrialised regions in the world. <BR/><BR/>This GISS Arctic data provides other points of interest such as the fact that the arctic warmed almost 2 deg C during the 1910-1940period, i.e. far more than any other region. I don't accept that this was due to ghgs (or the sun). Even in 1958 the atmospheric CO2 concentration was only ~315 ppm - equivalent to an increased forcing of ~0.5 w/m2 above pre-industrial levels. <BR/><BR/>The reconstruction model is missing a huge factor which is masked by the averaging of temperatures over the world. <BR/><BR/>My bet that missing factor is the ocean.John Finnhttps://www.blogger.com/profile/06614613390849062784noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-49628000776567379602009-02-23T01:46:00.000+00:002009-02-23T01:46:00.000+00:00Basically yes, that gap indicates a gap in our und...Basically yes, that gap indicates a gap in our understanding (as a lower bound!), although note that we would expect a little bit of mismatch at the 95% level anyway (not as much as appears in the plot though).<BR/><BR/>As a possibly non-exhaustive and arbitrarily-ordered list of reasons for the discrepancies:<BR/><BR/>The external forcings are imperfect, and some marginally significant ones are missing (eg land use). The obs have some biases (remember <A HREF="http://julesandjames.blogspot.com/2008/06/more-on-that-sst-change.html" REL="nofollow">this</A>, which I expect to slightly improve the fit once a correction is made) and even if these were all corrected, the global time series is not precise anyway due to limited coverage (note how gistemp and hadcru differ even though they use almost precisely the same original obs data). The model may have inadequate natural variability on the appropriate time scales - I don't know about this model in particular, but none of them really do ENSO/PDO/NAO "correctly". And last but perhaps not least, the model response to the external forcings is certainly not perfect anyway.<BR/><BR/>But we can clearly do a far better job with a comprehensive analysis than by just using CO2 forcing with an 11 year lag!James Annanhttps://www.blogger.com/profile/04318741813895533700noreply@blogger.comtag:blogger.com,1999:blog-9959776.post-35927601407199288382009-02-22T18:37:00.000+00:002009-02-22T18:37:00.000+00:00James (realizing this question might also be addre...James (realizing this question might also be addressed directly to globalwarmingart) -- on that illustration, would it be reasonable to take the difference between "observed" and the area outside the "predicted" gray-fuzz range and chart that as "missing/unexplained" (or somehow express how much of a gap remains)?Hank Robertshttps://www.blogger.com/profile/07521410755553979665noreply@blogger.com