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Comments 93701 to 93750:

93701. ranyl at 10:04 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       "ranyl @3, while a carbon price will not significantly reduce demand for energy, to which we are adicted, it will significantly change the best means of sourcing that energy. The only way this is not true is if alternative power sources are so inefficient as to by not commercially viable at any reasonable price (contrary to the claims of their advocates)." Hi Tom, But as oil prices have jumped since 2006, and fossil fuel use hardly blinked an eye, what evidence is there that a higher price unless much higher will make any difference to use really? Strikes me whatever the evidence CO2 emissions aren't stopping any time soon unless some miracle happens so all these discussions really are academic. Suspect it is probably prudent to start planning adaptation, with clear goals of carbon sequestration (this would a miracle or an enigma size effort), rapid transformation to a low energy use none fossil fuel society. Not sure renewables are the all saving grace, wind farms do heat and dry the land as well several other things, solar panels are associated with tri-nitro_floride release and rare metal mining, large dams casue huge CO2 releases from ecological effects and so on. Not using energy is in a real challenge but surely not worth taking the risk of CO2 levels over 400ppm for?
93702. Timothy Chase at 09:34 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       Bob Tisdale wrote:

       The difference in the multdecadal variability of ENSO (NINO3.4 SST anomalies as a proxy) and the PDO should be a function of North Pacific Sea Level Pressure...

       It's not eye balling as they use statistics, but you might be interested in Di Lorenzo et al. (2010 ) ENSO and the North Pacific Gyre Oscillation: an integrated view of Pacific decadal dynamics (presented at AGU 2010 Ocean Sciences Meeting) nevertheless.
93703. Bob Tisdale at 08:55 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       Timothy Chase: The difference in the multdecadal variability of ENSO (NINO3.4 SST anomalies as a proxy) and the PDO should be a function of North Pacific Sea Level Pressure, with the SLP altering the strength of the gyre spin-up into the KOE.
93704. mspelto at 07:49 AM on 6 March 2011
       Icing the Medieval Warm Period
       The variations of the Donne Glacier, Tasman Glacier and Murchison Glacier in New Zealand highlight the general response of NZ glaciers.
93705. scaddenp at 07:32 AM on 6 March 2011
       Icing the Medieval Warm Period
       "If at 5pm tonight, you were provided with Peer reviewed, non-cherry picked, Scientific evidence that there is no mad made global warming...Would you be a)Happy ? or b) Angry ?" Well first I would be skeptical, because a claim that strong would need the evidence tested rigourly by other workers. Then I would be ecstatic. Who wouldn't be? But what has this got to do with glaciers and MWP?
93706. Timothy Chase at 07:21 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       Sometimes I think the language used to describe "climate oscillations" is somewhat unfortunate. To many the term "oscillation" suggests periodic behavior. This is compounded by references to "climate oscillation's" "period." But the behavior of climate oscillations is generally not periodic. Instead there is a characteristic time scale that appears to be associated with a form of bistability where the system tends to be in either one state or the other. Your reference to "atmospheric noise" is suggestive of the nonperiodic nature of the Pacific Decadal Oscillation's non-periodic, or alternatively, quasi-periodic behavior. The Pacific Decadal Oscillation has a couple of characteristic time scales. Atmoz gives a detailed explanation of the correlation between PDO and global temperature in which he mentions two different characteristic time scales:

       Sometimes, it's said that the PDO has a characteristic time scale, hence the word decadal in the acronym. The UW website states that "Shoshiro Minobe has shown that 20th century PDO fluctuations were most energetic in two general periodicities, one from 15-to-25 years, and the other from 50-to-70 years." To evaluate this, we can look at a wavelet analysis of the PDO with trend derived in the first part of this post. On the Relationship between the Pacific Decadal Oscillation (PDO) and the Global Average Mean Temperature Atmoz, 3 Aug 2008 http://atmoz.org/blog/2008/08/03/on-the-relationship-between-the-pacific-decadal-oscillation-pdo-and-the-global-average-mean-temperature(emphasis added)

       The longer characteristic time scale is comparable to that which presumably exists for the Atlantic Multidecadal Oscillation. Please see:

       Michael E. Mann, associate professor of meteorology and geosciences, Penn State, and Kerry A. Emanuel, professor of atmospheric sciences, MIT, looked at the record of global sea surface temperatures, hurricane frequency, aerosol impacts and the so-called Atlantic Multidecadal Oscillation (AMO) — an ocean cycle similar, but weaker and less frequent than the El Nino/La Nina cycle. Although others have suggested that the AMO, a cycle of from 50 to 70 years, is the significant contributing factor to the increase in number and strength of hurricanes, their statistical analysis and modeling indicate that it is only the tropical Atlantic sea surface temperature that is responsible, tempered by the cooling effects of some lower atmospheric pollutants. Climate change responsible for increased hurricanes Tuesday, May 30, 2006 http://live.psu.edu/story/18074(emphasis added)

       Shorter characteristic time scales would be suggestive of oscillators associated with shallower ocean ocean phenomena that would be more easily influenced by interactions between the atmosphere and ocean whereas longer characteristic time scales suggest that bistability involves changes in deepwater ocean circulation. In addition to the correlation between PDO and ENSO phases over time you have the fact that the two are virtually identical in spatial distribution but for the fact that PDO is strongest in the North Pacific whereas ENSO is strongest in the Equatorial Pacific. But during their warm phases both are cool in the North Pacific and warm in the Equatorial Pacific. You can see this here: Figure 1 Warm Phase PDO and ENSO. http://cses.washington.edu/cig/figures/pdoensoglobe_BIG.gif... from: The Pacific Decadal Oscillation http://cses.washington.edu/cig/pnwc/aboutpdo.shtml So there is a bit more to go on than simply a temporal correlation between two scalar values. What we have is an areal and temporal correlation between two two-dimensional fields that vary over time. Essentially, over the entire area of an ENSO, the warm phase of the PDO would appear to result in constructive interference with the warm phases of ENSO and destructive interference with ENSO’s cool phases, whereas the cool phase of PDO results in deconstructive interference with the warm phases of ENSO and constructive interference with ENSO’s cool phases. So it shouldn’t be any surprise at all that El Ninos are typically stronger, longer and more frequent during the warm phase of PDO and La Ninas are typically stronger, longer and more frequent during the cool phase of PDO. Spatial destructive interference might also help to explain the existence of a lead-lag relationship where an El Nino will tend to cause the Pacific Decadal Oscillation to tip from its negative phase to its positive phase. Feedbacks, both positive and negative, are part of an integrated theory of ENSO put forward in: Chunzai Wang (March 2001) On the ENSO Mechanisms, Advances in Atmospheric Sciences (Special Issue) Such feedbacks no doubt result in much of the observed quasi-stability of PDO states and would help to explain the observed lead-lag relationship between El Nino and the Pacific Decadal Oscillation, e.g., an El Nino weakening or overwhelming the negative phase of the Pacific Decadal Oscillation, making it easier for the latter to switch to its positive phase. Positive feedbacks no doubt help to explain the quasi-stability of the two states of the Pacific Decadal Oscillation. An El Nino may weaken or even overwhelm the negative phase of the Pacific Decadal Oscillation, making it easier for the mode to slip from its negative phase to its positive phase. PDO lags ENSO on the scale of several months:

       ENSO also leads the PDO index by a few months throughout the year (Fig. 1d), most notably in winter and summer. Simultaneous correlation is lowest in November–March, consistent with Mantua et al. (1997). The lag of maximum correlation ranges from two months in summer (r ~ 0.7) to as much as five months by late winter (r ~ 0.6). Matthew Newman et al (1 Dec 2003) ENSO-Forced Variability of the Pacific Decadal Oscillation, Journal of Climate, Vol 16, No 23

       ... and several years:

       There is potential a lead-lag relationship between the time variability of PDV2(i.e., the PC time series of PDV2) and N34Var although it does not exceed a statistical significance test. Figure 5c shows the lagged correlations of N34Var with the PC of PDV2. Note that the thick line indicates the 95% significant level and negative lags indicate the N34Var preceding the PC of PDV2. The maximum correlation occurs at lags of approximately 3~4 years with positive correlation. This indicates that the N34Varleads the variability of PDV2, suggesting that the Pacific mean state, which is identified by the PDV2, is due to a residual associated with larger or small ENSO amplitude. Sang-Wook Yeh and Ben P. Kirtman (May, 2004) Pacific Decadal Variability and ENSO Amplitude Modulation

93707. dhogaza at 07:13 AM on 6 March 2011
       Icing the Medieval Warm Period
       "If at 5pm tonight, you were provided with Peer reviewed, non-cherry picked, Scientific evidence that there is no mad made global warming...Would you be a)Happy ? or b) Angry ?" I'd wonder why my CO2 laser still works, personally.
93708. williambaskerville at 07:05 AM on 6 March 2011
       Icing the Medieval Warm Period
       @ DB Actually a bit "flattening": For example UAH Satellite-Based Temperatures until Feb. 2011:
       Moderator Response: [Dikran Marsupial] Images (hopefully) fixed. BTW, the difference is the "exogenous factors" that Daniel's caption mentioned. The article by Tamino is well worth reading.
93709. stevee3906 at 07:05 AM on 6 March 2011
       Icing the Medieval Warm Period
       My question..was deleted !! If at 5pm tonight, you were provided with Peer reviewed, non-cherry picked, Scientific evidence that there is no mad made global warming...Would you be a)Happy ? or b) Angry ? Why was there cooling in the 70's, the C02 models demand that temp rise with C02, yet they did not, as you stated. http://en.wikipedia.org/wiki/File:Holocene_Temperature_Variations.png Why stop at 2,000 years, try the period in the above link. Why are the Polar Ice caps on Mars melting ? Solar Activity.
       Moderator Response: [Dikran Marsupial] I would be delighted. However it might be a good idea if you were to acquaint yourself with the responses to common skeptical arguments already documented on this site. Firstly models do not demand temperature rises with rising CO2 because CO2 is not the only driver of climate, you also might want to look at Why did climate cool in the mid-20th Century?. Secondly, we know it has been warmer in the past, see What does past climate change tell us about global warming? . Lastly, the climate change on Mars is thought to be due to changes in albedo, see Global warming on Mars, ice caps melting . It is unlikely to be solar activity, see the response to the number one skeptic argument it's the sun. The reason your question was deleted was that, again, it violated the comments policy, for the same reason your previous post was deleted.
93710. scaddenp at 07:03 AM on 6 March 2011
       Icing the Medieval Warm Period
       On various periods of ice expansion in NZ. Is this because NZ got colder? No. The alps perpendicular to the predominantly westerlie flow (same in Argentina). A warmer Tasman sea increases snowfall and hence the advance. But the terminus warms too so this doesnt go on forever. In a Franz Josef response study, it was calculated that needed in long term to increase precipitation by 40% for each 1 degree of temperature rise in ablation zone (from memory - paper at work). Again, read glacial data with care.
93711. Rob Painting at 07:03 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       Blessthefall @ 38 - Rob, I don't see how one country reducing emissions will do anything if the rest of the world goes unchecked. It doesn't make any sense. If one of the main polluters, like the US, decides to curb greenhouse gas emissions, others will follow suit. If the US proves it can be done without crippling their economy why wouldn't others do the same?. Mind you this is highly hypothetical, your political system seems to be in the thrall of the Sith. What doesn't make any sense is continuing to rely on a limited and severely polluting energy resource. Peak oil occurred around 5 years ago, so there's only one way the price of oil is headed and that is up,up,up. Not making the transition to renewables, is going to be one of the defining blunders of the 21st century. If you want to talk environmental costs, that's something completely different. Different in that the true cost doesn't have to be borne by those damaging the environment. Passing the buck to future generations will not be appreciated by said future generations. Or even current generations, when you factor in that the extra 4% of global water vapor and the extra heat that fossil fuel combustion has bought about. To pay their fair share, fossil fuel companies would have to cover a proportion of all damaging weather events around the globe. See what I mean about expensive?. Economists simply ignore this stuff and give it a fancy name "externalizing". Blaming global warming for food shortages is a non-sequitur. No, actually it's fact. Don't you remember the Russian heatwave last year?. You know where they banned exports of grain after huge losses from the heatwave?. And that's just one major event. I've argued for a long time on other blogs that the first consequence of global warming will be expensive food prices from weather extremes (principally drought). Joe Romm over at Climate Progress has been hammering home that point for a while now. And after experiencing the warmest wettest year on record (2010) global food prices are at an all-time high. You should keep an eye on the FAO index, sure there will be ups and downs, but long-term that is going to skyrocket too.
93712. Alexandre at 06:30 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       Suggestion for a future post: fossil fuel subsidies.
93713. Camburn at 06:21 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       Rob: If you think food prices are rising now, enact a co2 tax and you will see reallllll rises in food prices.
93714. Eric (skeptic) at 05:56 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       Riccardo, you're right, you did. Sorry about that. Perhaps Spencer did indirectly consider the early 20th TSI increase in the sense that it is reflected in the PDO index.
93715. williambaskerville at 04:43 AM on 6 March 2011
       Icing the Medieval Warm Period
       @ stevee I personally think that talking about a 'Medieval Climate Anomaly' does not really make sense. What does it mean to say this is a normal this an abnormal state of climate? We do not have the "view from nowhere" to do so. If we take the last 2000 years for example, than we find in some places evidence for a so called "Roman Warm Period" in most places evidence for a "Medieval Warm Period" in almost every places evidence for a "Little Ice Age" and at least a "Current" Warming (WP), starting something about 1850. Example: Are these periods anomalies? If we take a look on the last 100 years we see a warming from 1910 until 1940, a cooling until the 70s and a warming until the "peak" 1998, then a flattening of the curve. So I am convinced it is better to talk about a MWP and not a MCA.
       Moderator Response: [DB] Actually, not-so-flattened: 5 datasets, exogenous factors removed (Tamino)
93716. Paul D at 04:34 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       SNRatio: "It's much more complex. First, the simplest, way to cut consumption, in general, is using longer-lived goods." ---or increasing prices--- Quality = higher prices.
93717. Riccardo at 04:30 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       Bob Tisdale you're right, that's what I wanted to say when I noted that the definition is USA-centric.
93718. Blessthefall at 03:59 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       Marcus and rob: Just a note to Marcus, this is the last time I'll acknowledge you. If you want to have a civil debate about something I suggest not speaking to someone like they're a 5 year old. Continually associating my or anyone else's beliefs with the fossil fuel industry gets people no where and quite frankly, it's frustrating: I am all for renewable energy just as long as it's just as efficient and cheap as oil or coal or nuclear. I have some articles/books that you can read which shows that the fossil fuel industry is involved with you and your ilk. That's right, they're actually pro-global warming because they can make money. When you decide to grow up, let me know and I'll be happy to provide the books. On to my response: My point is that if there's any industry that can profit from renewable energy, if there is any industry that can possible produce renewable energy on a large scale, it'd be the fossil fuel industry. Why? They have a massive amount of resources. Whether they decide to invest that into renewable energy or buy the renewable energy companies, they win either way. Rob, I don't see how one country reducing emissions will do anything if the rest of the world goes unchecked. It doesn't make any sense. Some say it's a "good place to start," but what good is it doing when China and India's emissions continue to rise? As far as the cost of energy, the actual production and shipping of the energy is what I'm factoring in. If you want to talk environmental costs, that's something completely different. Also, you bring up the rising cost of food... farmers are paid to underproduce. The United States alone could feed the entire world. Blaming global warming for food shortages is a non-sequitur.
93719. SNRatio at 03:51 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       #33: "Ultimately individuals have to cut consumption, you can't do that just by moving things around. You either have to have a cultural change, or increasing prices, or rationing." It's much more complex. First, the simplest, way to cut consumption, in general, is using longer-lived goods. Building better things. Second, using mostly recycleable materials. Third, emissions per produced entity are by no means a well-defined quantity. Moving production around may be a very good idea, to have optimal locations. Producing Aluminium where there is a surplus of renewable energy, for instance. It depends on the rules of the game. Fourth, changing consumption patterns may be much more important than, generally, cutting consumption. Using fossile products only as industry raw materials and for special purposes, for instance. Substituting bio-products for fossile products may, by several criteria, actually increase consumption. But as long as it is sustainable, it may be the right thing to do.
93720. dana1981 at 03:42 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       thingadonta #3:

       "these 3 coupled periods (sun+-PDO) correspond better than c02 does in the 20th century...implying that climate sensitivity to c02 is low."

       Sorry no, you don't calculate climate sensitivity by looking at correlations. PDO does not cause long-term warming trends so it has no impact on climate sensitivity. Not to mention the fact that you're comparing a combination of multiple effects to just a single effect (CO2). CO2 doesn't act in a vacuum - you also have to take into consideration all other forcings in addition to CO2.
93721. dana1981 at 03:35 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       garythompson #15:

       "the purpose of this post was to show how carbon cap and trade improved business.

       No, it wasn't. I thought I pretty clearly outlined the purpose of the post - to debunk three myths related to carbon pricing. 1) That it will cripple the economy. 2) That it will kill jobs. 3) That it will make energy bills skyrocket. Cap and trade being pro-business didn't even make the list, let alone being the purpose of the post! As an added discussion, I noted that the New Hampshire House leader had claimed that killing cap and trade is pro-business, which is clearly not the case.
93722. stevee3906 at 02:46 AM on 6 March 2011
       Icing the Medieval Warm Period
       The entire premise of "Icing the MWP" and suggesting that the name be changed to " the Medieval Climate Anomaly" must be based on changing temperatures/climate is an .. Anomaly. The climate is always changing. If climate stayed the same that would be an Anomaly. The Climate changed long before the any effect from manmade activity.
       Moderator Response: [Dikran Marsupial] See the response to the second most used skeptic argument Climate's changed before.
93723. stevee3906 at 02:23 AM on 6 March 2011
       Icing the Medieval Warm Period
       As climate is the study of long term averages and trends, the MWP is essentially just noise. The earths temps have been documented to be much higher at times in the past. http://en.wikipedia.org/wiki/File:Holocene_Temperature_Variations.png.
       Moderator Response: [Dikran Marsupial] By long term averages/trends, I meant sufficiently long to average out the weather noise. Climatologists generally take that to mean starting at about 30 years. The MWP ocurred over a long enough timescale to be 'climate' rather than 'weather' (noise).
93724. Marcus at 02:07 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       Here's the thing Gilles. My current annual fossil fuel consumption is less than *half* what it was 10 years ago-yet far from being *poorer*, I'm now *richer*-because my energy bills are lower. This has not come at any cost to my standard of living-as my house still has access to all the mod-cons as before-just using the most energy efficient technology available. So I guess my point is that reducing fossil fuel consumption does *not* have to mean entrenching poverty-its about ensuring that development is achieved in the most CO2-neutral manner possible. I do find it odd, though, is that those who speak most loudly about the poverty which CO2 abatement will cause weren't too loud in speaking out against the poverty caused by corporations paying the people of these poor countries next to nothing for their labour & resources.
93725. stevee3906 at 01:51 AM on 6 March 2011
       Icing the Medieval Warm Period
       Currently the Scientific Data shows the global satellite data at 0.02 below the 30 year average. http://www.drroyspencer.com/latest-global-temperatures/
       Moderator Response: [Dikran Marsupial] This appears to have little relevance to the article under discussion. Climate is the study of long term averages and trends; observations about current temperatures are essentially just weather noise and don't give a reliable picture of what the climate is actually doing. The same was true of the peak in 1998. I've made your link clickable to encourage others to view the data.
93726. stevee3906 at 01:39 AM on 6 March 2011
       Icing the Medieval Warm Period
       Why did you delete my post regarding Global Warming, MWP the IPCC errors ?
       Moderator Response: [Dikran Marsupial] Your post was deleted because it violated the comments policy (specifically the first item on the list). Keep to the science and your posts will not be deleted (provided it is not off-topic for the thread of course).
93727. Alexandre at 01:15 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       Riccardo Thanks for your response. So the North Pacific has been warming, sometimes a bit ahead of the entire global ocean, sometimes a bit behind. When it's ahead we have a negative PDOI and vice versa (right?). Look, I may be just giving away my own ignorance, but I cannot grasp any physical meaning of this index to justify it "pulling" the Earth's temperature up or down. It's just an oscillation between two different temperature distribution patterns. A very positive PDOI does not mean a particularly warm ocean (Global, at least. I tried to find some SST time series of the Pacific alone, and could not find any.)
93728. Bob Tisdale at 01:05 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       Riccardo: Your post misses a very important point. You defined the PDO, but failed to clarify it. The PDO data from JISAO does NOT represent the Sea Surface Temperature (SST) anomalies of the North Pacific, north of 20N. In fact, on decadal timescales, the SST anomalies of the North Pacific (north of 20N) are inversely related to the PDO. The following graph presents the North Pacific SST anomaly residual (North Pacific SST anomalies MINUS Global SST anomalies) versus scaled PDO data, with both datasets smoothed with a 121-month running-mean filter. http://i52.tinypic.com/ipaxjr.jpg Now if we invert the PDO data (multiply it by a negative scaling factor) we can see how closely they are related. http://i52.tinypic.com/15oz3eo.jpg In other words, during epochs when the PDO is negative, the North Pacific SST anomalies are greater than global SST anomalies. For a more detailed discussion, refer to: http://bobtisdale.blogspot.com/2010/09/inverse-relationship-between-pdo-and.html
93729. Paul D at 01:03 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       2010: UKs chief environmental scientist points out UK emissions have gone up, once exported emissions are taken into account: http://www.bbc.co.uk/news/science-environment-11172239
93730. Gilles at 01:00 AM on 6 March 2011
       Climate Sensitivity: The Skeptic Endgame
       e#97 : again, I don't think that a probability distribution based on a collection of heterogeneous models and measurements has any clear signification, especially if you're interested in the peak in the distribution ! just because the position of this peak will shift following the number of bogus models you add in the sample.
93731. Paul D at 00:58 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       Bern: "I think it's a *very* low bow to draw to blame the decline of manufacturing in western nations (including both the EU and the US) on efforts to fight global warming." That isn't what I wrote. The fact is companies have exported emissions to China in the race to reduce costs and compete. I didn't say it was a result of current efforts to cut emissions. However, if you include emissions produced by China for goods that would have been produced in the EU in the past, then, EU emissions haven't gone down much. In fact I think there was a UK report out last year that showed UK emissions had gone up or remained static once emissions exports had been taken into account. Ultimately individuals have to cut consumption, you can't do that just by moving things around. You either have to have a cultural change, or increasing prices, or rationing.
93732. Riccardo at 00:36 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       A general clarification related to some of the comments (johnd, Gilles, thingadonta). The point of the whole post is to show that the PDO alone cannot be the cause of current warming (Spencer's claim) and that what we know makes clear that it cannot even be considered as a forcing by itself. johnd frequency has indeed changed over time, as I showed, but as far as the PDO as a forcing is concerned it is irrelevant; it would anyway produce a tmporary warming trend. Lacking a long term trend in the PDO index rules out it's role. Fig 3 should make it clear. thingadonta I intentionally "faiiled to mention etc." because my point was exactly that, we can not use the PDO index this way. Moreover, how come you compare PDO+sun with CO2 alone? You can not play with the forcings you convenience, putting in the ones you like and leaving out those you don't like. Alexandre I do not have the figure you're asking for. Though, we know that the North Pacific Ocean is warming overall and that the PDO index tells us just if it is warming more or less than the global oceans. michael sweet I take your comment as a compliment. I'm not involved in any research involving climate, but I'm a scientist and I'm used to read the scientific litterature thoroughly whenever I find a scientific issue interesting. Eric (skeptic) I explicitly quoted the definition of the PDO index. Spencer, again explicitly, tried to show that the PDO index alone could explan a good part of the XX century warming. He added the CO2 forcing afterwards to account for the late XX century increase while the PDO index was decreasing. He didn't even considered the well know TSI increase durng the first half of the century.
93733. protestant at 00:30 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       Yes, Roy Spencer explained the warming trend with a weaker CO2-effect + the PDO. And then he is being attacked on "adding a trend to PDO" which is the human attribution in his simple model. He has done nothing wrong investigating alternative hypothesis'.
93734. Bern at 00:10 AM on 6 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       The Ville - I think it's a *very* low bow to draw to blame the decline of manufacturing in western nations (including both the EU and the US) on efforts to fight global warming. It's got a whole lot more to do with the cost of labour - the 'outsourcing' of manufacturing to nations with extremely cheap labour has been going on ever since Walmart imported the first container loads of cheap Japanese goods... (and probably a heck of a lot longer!) The interesting (& rather sad) thing as that many of the same people responsible for that shift are now screaming that a carbon price will adversely affect manufacturing in western nations...
93735. Eric (skeptic) at 00:06 AM on 6 March 2011
       Blaming the Pacific Decadal Oscillation
       Riccardo, PDO is indeed not a forcing, it is an index reflecting the result of various natural forcings. Thus it explains some of the natural variation that overlays AGW. But there is an important fact about the index not mentioned above which is that the index has the global SST anomaly subtracted from it, see http://www.springerlink.com/content/5xm9ngv5fn5dc2r7/fulltext.pdf (Mantua and Hare 2002) where they explain: "Residuals are here defined as the difference between observed anomalies and the monthly mean global average SST anomaly (see Zhang et al. 1997)." I believe that is what Roy Spencer was trying to show by adding "CO₂" to PDO in his graph.
93736. neilrieck at 23:28 PM on 5 March 2011
       Roy Spencer’s Great Blunder, Part 3
       I am not sure if Roy Spencer promotes bad-science accidentally or on purpose, but this is not the first time he has blundered. Recently I was searching through a database of the stolen emails from East Anglia colloquially known as Climate Gate. I found an email where researchers Mears and Wentz are mentioned as the discoverers of major mathematical errors in the algorithms used by Roy Spencer and John Christy. One error was the wrong algebraic sign. It turns out that the bad-science published by these researchers from the University of Alabama has been the primary reason why the climate models were questioned by the public at large. The errors where published in SCIENCE in 2005 with Spencer and Christy acknowledging the errors in the letters section of September 2005 issue. So why do Spencer and Christy continue to deny the science? Click the following link to see the details. http://www3.sympatico.ca/n.rieck/docs/climate_science.html#climategate
93737. angusmac at 23:28 PM on 5 March 2011
       Hockey Stick Own Goal
       Tom @ 136 and Anom @137, I agree that I should be using decadal averages nevertheless it doesn't change the outcome of my argument as shown below. I have plotted the MWP peak temperature as the red line and the modern peak as the blue line on Ljungqvist's (2010) temperature reconstruction in Figure C and it is evident that the MWP peak is 0.11 °C warmer than the modern peak, i.e. the MWP was warmer than the 1990-1999 mean temperature. Tom, I also agree that the GISS data show that 2000-2009 mean temperature is 0.18°C higher than 1990-1999. Now, if I assume that the proxy temperatures respond linearly with actual temperatures, the 2000-2009 peak would be 0.18 - 0.11 = 0.07°C higher than the MWP. This is hardly unprecedented warming and is about one-ninth of the 0.6 °C figure stated by Dana. Finally, the assumption that proxies would increase linearly from the 1990's to the 2000's questionable because, "…recent proxy data does not emulate the recent instrumental data" (Ljungqvist, 2010). Proxy temperatures are much lower than the corresponding present-day instrumental temperatures (see Figure A in #132) i.e., the so-called divergence problem. What we really need are present-day proxies so that we can compare the current warm period with the earlier proxies.
93738. williambaskerville at 23:01 PM on 5 March 2011
       Icing the Medieval Warm Period
       @ Tom Curtis Unfortunately it seems to me that you are a person, arguing ad hominem: "silly" "look a fool". That's a real shame. You are not that kind of person I want to talk to at all. So this is the last post addressed to you personally. "However, you identify as one of your regionally cooling regions New Zealand." No, I just identify some glaciers in NZ advancing in the current (until 1998), global WP. "... of just one or two glacier records for only decade (instead of the whole century) is cherry picking. If you don't like the term, don't do it." Come on. The chart starts 1977 and not 1900. Your argument "overall decline" is only valid for the period 1998 until now, with the exception 2002-2005. If you will call this a "trend" than do so. I am fine with it. You can find a "trend" downwards on the scaled mass balance of New Zealand glaciers, starting 1998. That is true. "Finally ..." My post Nr. 33: "Gehen Sie von den möglichen Steuergrößen aus. Was bleibt übrig? Alles läuft auf dieser Skala auf die Sonne hinaus. Wenn dem so ist, müsste man sicher von einer globalen Anomalie ausgehen dürfen; natürlich durch interne Oszillationen modifiziert" My translation: Assuming potential actuating variables. What has been left? Everything leads on this scale to the sun. If this is the case, a global anomaly can be assumed; of course modified by internal oscillations. @ MarkR Scherler et al., Abstract: In contrast, more than 50% of observed glaciers in the westerlies-influenced Karakoram region in the northwestern Himalaya are advancing or stable. Our study shows that there is no uniform response of Himalayan glaciers to climate change and highlights the importance of debris cover for understanding glacier retreat, an effect that has so far been neglected in predictions of future water availability, or global sea level You are right but I don`t think this is an argument against my statement that we have increasing glaciers in the Karakorum.
93739. Gilles at 22:51 PM on 5 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       Tom#28 : I do fully agree with you. But I'm just saying that all "energy policies" reduce actually energy intensity - they do not control the whole emission rate, especially at a world wide scale. How can you prevent Chindia from using the oil spared by american hybrids vehicles? The Ville : actually hundreds of millions of chinese people went out of poverty in the last decade through an increase of their fossil fuel consumption. I think they would be happy if you show them how they could have made it in another way.
93740. mspelto at 22:48 PM on 5 March 2011
       Icing the Medieval Warm Period
       In the United States we have had a very severe recession over the last 30 months. The vast majority of companies had layoffs and suffered financial losses, a number went out of business. That a few companies continued to grow is not evidence there was not a recession. The same holds for glaciers. Almost all are losing considerably volume, some are disappearing, a very few are not losing volume. The glacier volume loss is global and a strong indicator of global warming. The glaciers advancing noted by Koch and Clague are sufficient in number to indicate that they are not the small anomaly of today's advancing glaciers. The advances were also large enough to advance well beyond their former margin, that is not happening anywhere today. Again look at the synchronous response of northwestern North America glaciers in terms of mass balance change, and how this curve looks like the global signal, Rainbow Glacier charts near bottom. The latter graph I just submitted this week for BAMS State of Climate Report 2010, for the glacier section.
93741. michael sweet at 22:46 PM on 5 March 2011
       Blaming the Pacific Decadal Oscillation
       Thingadonta, Your entire post has a total of zero links to data. "Others have looked" is just a bunch of deniers who do not know how to analyze data,or fabricate distortions. Provide links to peer reviewed data. If you cannot provide links to the data you will not convince anyone you have anything to say. Riccardo, You certainly have a lot of appropriate links to peer reviewed data. Are you involved in research in this field?
93742. Tom Curtis at 22:33 PM on 5 March 2011
       Blaming the Pacific Decadal Oscillation
       thingadonta, what is the correlation (r^2) between the temperature increase and solar output - PDO with a monthly plot. IF you only have a smoothed plot (which exagerates correlation) what is the correlation for that smooth plot, and what is the smoothing. And who worked this out, and where did they work it out?
93743. MarkR at 22:32 PM on 5 March 2011
       Icing the Medieval Warm Period
       #15 williambaskerville: I did read one recent paper on Himalayan glaciers in Karakoram. It was widely reported as 'Himalayan glaciers growing' (although the Telegraph have now changed their title on that article as far as I can see). This paper looked only at area changes, and isn't a proper mass balance. But changes in accumulation might be increasing their volume there. Maybe. In terms of area, more than half were expanding there, but the mean change in area was negative i.e. total area went down in Karakoram. The data is available if you look in the supplementary material, I decided to check for myself after all the popular media rants about how they were growing... williambaskerville at 22:49 PM on 4 March, 2011 Hi, I don't think this is a argument against the MWP. Don't we actually have increasing glaciers in Norway, New Zealand and the Karakorum? Don't we have regions in the world, not getting warmer?
93744. Kevin C at 22:14 PM on 5 March 2011
       Blaming the Pacific Decadal Oscillation
       thinadonta@3: Have you tried factoring out the solar cycle from the temperature trend? Tamino does it here and several others have done similar calcs. Once you take out the effect of the solar cycle, the flattening since 2000 (which would probably be better described as an anomalously fast increase leading up to 2000) is replaced with a pretty linear trend. Here's a paper on the same thing: Lean and Rind (2009), GRL 36.
93745. Alexandre at 22:07 PM on 5 March 2011
       Blaming the Pacific Decadal Oscillation
       To me it's not even clear that the PDO "warm" phase means a warmer Pacific SST as a whole. Eyeballing the figures, it looks like the "warm" phase could even be cooler than the "cold" one. Let alone warm the globe. Does anyone have a quantitative figure?
93746. Paul D at 21:43 PM on 5 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       Gilles:"for a given energy intensity, doesn't it mean that we would just prevent poor people of getting richer ?" Being poor is a political/social issue that is separate from policies legislating for carbon. If you are worried about the poor, then you are dealing with an age old issue that exists throughout history. Why would you think you are going to solve it with cheap fossil fuels? So by all means tackle it in the context of 'traditional' (aka 20th century left/right arguments). But don't pretend that a global issue that has an impact on poor and rich and different species, can be drawn into this age old and failed discussion about the 'poor'.
93747. Paul D at 21:37 PM on 5 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       As ranyl has pointed out, emissions in some cases have been exported from the EU to China/India. This is a well known issue. It is definitely the case in the UK where manufacturing has shrunk enormously and where cargo containers coming to the UK are 100% full, whilst those that leave are 50% empty. Offloading manufacturing to other nations doesn't reduce emissions, the chase for cheaper labour, fuel etc increases emissions.
93748. Tom Curtis at 21:01 PM on 5 March 2011
       A Real-World Example of Carbon Pricing Benefits Outweighing Costs
       Gilles, the atmosphere does not give a hoot about our Carbon intensity. Carbon intensity is not a physical cause of anything. Carbon dioxide emitted to the atmosphere, on the other hand, is a cause of global warming. So, I don't care a hoot what you do with your "carbon intensity" if it does not reduce total carbon emissions. On the other hand, reducing carbon emissions while preserving economic growth will inevitably reduce carbon intensity (seeing you like reductions in abstract quantities so much). Further, probable consequences of Business As Usual include the loss of the Amazon rain forest, and the loss of the Great Barrier reef. These are costs always left out of economic assessments of the proper value of carbon reductions, and for good reason. If they were left in, it becomes self evident that the cost of not reducing carbon emissions is too great.
93749. Tom Curtis at 20:50 PM on 5 March 2011
       Icing the Medieval Warm Period
       WB, your "point" is that there are regionally cooling areas in the modern warm period, so that identifying regionally cooling areas in the 10th and 11th centuries does not disprove the existence of a global MWP. I think that point is valid, as I have said. However, you identify as one of your regionally cooling regions New Zealand. As it happens, NZ has been warming over the course of the 20th century, and over that period its glaciers have been retreating, with some short duration exceptions. Therefore picking on NZ as one of your cooling regions on the basis of just one or two glacier records for only decade (instead of the whole century) is cherry picking. If you don't like the term, don't do it. Seeing a graph that obviously shows an overall decline in and then picking out just those sections of the graph which show an increase in mass balance is very silly. It is cherry picking when the refuting evidence is directly in front of us, and can only make the person who does it look a fool. Either you have a bizzare straw man view of global warming that says that all temperature rises, or glacial retreats will be monotonic; or you suffer under the mistaken notion that Koch and Clague only show occasional decades of glacier expansion against a backdrop of centuries long decline (rather than the reverse as they claim); or by pointing out short periods of increase against a backdrop of overall decline, you are cherry picking. Finally, you are apparently a German speaker. If you were not, then presenting an untranslated German text as evidence would be simple foolishness for you would not know what it means. As a German speaker, with evidently reasonable English skills translating the text should be no problem to you. If, however, you think the text is so unimportant that the Google translator can be trusted to give its sense, then I will take that assessment at its face value, and not bother. Anything whose sense is so unimportant that it can be trusted to google is not worth reading. (Your refusal to translate the German passages is a fair indication that you are merely making an implicit appeal to authority. It is the "Dr" in front of the name that is evidently important, not what they said, which you cannot be bothered conveying to us.)
93750. thingadonta at 20:49 PM on 5 March 2011
       Blaming the Pacific Decadal Oscillation
       Even though the PDO would not explain a long term rising T trend, when coupled with rising solar output from 1750-1850, it correlates well with early 20th century warming (+increasing solar output), mid 20th century cooling (+flattening solar output), less so with late 20th century warming (flattening solar output). But what you have faiiled to mention is that these 3 coupled periods (sun+-PDO) correspond better than c02 does in the 20th century (eg mid 20th century cooling with rising c02), implying that climate sensitivity to c02 is low. That is, the c02 effect is weak when you intergrate PDO, solar trends, and c02 trends in the 20th century, and also up to the 1st decade of the 21st century. Others have looked at this and come up with a correlation of 24% between T and c02 since 1850, and it's currently falling (rising c02 but flattening T). This together implies very weak climate sensitivity to c02, and that most of the warming since 1900 has been from solar output + 20 year+ heat lag effects, coupled with PDO oscillation + lag effects (heat derived from same source since 1750-warming sun). C02 effect has been increasing since 1950 but is still weak, as also seen in the flattening of T since 2000.

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