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Tom Curtis at 09:48 AM on 16 June 2011It's the sun
Tor B @826, Stockwell provides very little information to provide a counter analysis. The majority of the information comes from this diagram:
As you can see, he plots temperature against the cumulative solar forcing. The only way that can be appropriate is if there has been no increase in Outgoing Longwave Radiation to dissipate the increased incoming solar energy, thus allowing it to accumulate. As a rise in temperature will result in a rise in OLR all else being equal, he leaves entirely unexplained why OLR has not increased over the period, and why it did increase in previous centuries, thus allowing the solar forcing to dissipate and temperatures to not rise as they have in the twentieth century. What Stockwell needs, therefore, is a mechanism that provides a near linear reduction in OLR over time. (Care to guess where this is going?)
Oddly, and obviously, there is a known mechanism which has been increasingly been reducing the OLR over the course of this century. It is the increase in the Greenhouse Effect due to increased anthropogenic emissions of Greenhouse Gasses. Indeed, the increased forcing (reduction in OLR for a given surface temperature) has risen approximately linearly over the last half of the twentieth century:
Further, it turns out that using a linear increase in anthropogenic forcings plus solar forcings, plus volcanic forcings plus the MEI (an index of the El Nino Southern Oscillation), an even better correlation with temperatures can be found than that found by Stockwell:
So it turns out that the evidence Stockwell has uncovered is in fact evidence of an increasing anthropogenic forcing - he is just not good enough an analyst to realise it.
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LazyTeenager at 08:30 AM on 16 June 2011The Planetary Greenhouse Engine Revisited
The thing which struck me about Steve Goddard's venus article on WUWT (its all due to pressure not CO2) is that he used the diifferential form of the formula for variation of temperature with height. The normal formula would have had an integration constant T0. This means he managed to neglect/ignore/hide an important variable that in effect describes the overall the temperature of the atmosphere. -
Charlie A at 08:02 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
@Rob Honeycutt --- "Tamino skin this cat quite differently and comes up with statistical significance from 1995-2009" He didn't find statistical significance in either HadCRUT3 or HadCRUT3v. To quote Tamino "[Response: Only by removing the influence of exogenous factors (el Nino, volcanic, solar) can you show statistical significance post-1995.]" The "Tamino" series starts of with the HadCRUT3v, which Phil Jones himself says has artifacts from the gridding method that makes HadCRUT3 the recommended data for time series analysis. Tamino then applies his own recipe of modification to remove such things as solar influence. Then he does an analysis. The analysis is interesting, but doesn't support Phil Jones's statement.Moderator Response: (DB) Actually, Tamino's analysis showed that the warming since 2000 and earlier was statistically significant. -
scaddenp at 07:55 AM on 16 June 2011Are you a genuine skeptic or a climate denier?
Eric(sk) - still interested in the questions of resolving conflict of rights and legal responsibility. -
Bob Lacatena at 07:52 AM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
42, Eric the Red, You are taking an alchemists approach to climate science. You are treating all of the components as great mysteries of the aether and phlogiston, with the idea that if you can just tease out all of the variables -- not by understanding the mechanics through constructing simple, logical laws and then clearly predicting the impacts, but rather merely through observation, correlation and inference -- then you'll eventually have enough information to prove to yourself that the one variable that is derived from and defined by mechanistic understanding, and which has all along predicted observed events, is in fact the major and almost only cause of the trend. But in the meantime, do you counsel that we should wait and see (what, 30 years?), to be sure the PDO isn't some magical perpetual motion machine that is somehow adding energy to the system with no source to propel it? -
Paul Magnus at 07:49 AM on 16 June 2011Speaking science to climate policy
totally agree! -
scaddenp at 07:48 AM on 16 June 2011The greenhouse effect is real: here's why
ChrisG - "If the source of the extra C in the past was methane from permafrost or clathrate, then the 13C / 12C ratio would be the same as fossil fuels." No they are not. Clathrate methane appears to be predominately from microbial activity with d13 between -40 and -100, average ~60-65. FF is closer to plant with d13 around ~-30. This has been used as evidence against clathrates being big players in events like YD based on ice core methane. However, I am watching for more results from these studies, as well as ongoing work d13 in the PETM where clathrates are thought to be significant. -
scaddenp at 07:35 AM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
For consideration of what would happen if sun went into deep minimum, see Feulner and Rahmstorf 2010. Quick answer - by 2100, only a small temperature decrease compared to standard SRES scenarios. -
Rob Honeycutt at 07:34 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Charlie... Boy-o-boy did I have a knockdown drag out with Lubos Motl not long after the Phil Jones interview over whether anything less than 95% was real or not. Motl was absolutely adamant than anything less than 95% statistical significance, in fact, did not exist. Regarding Lucia... The old saying is, "There's more than one way to skin a cat." Tamino skin this cat quite differently and comes up with statistical significance from 1995-2009. -
Tom Dayton at 07:27 AM on 16 June 2011It's the sun
Stockwell's "work" sounds like the same-old-same-old overfitting of a curve with a whole bunch of parameters. -
Charlie A at 06:50 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
This whole topic is a tempest in a teapot. It is strange, though, that Phil Jones uses suspect statistics to make the claim that the warming is now statistically significant at 95% confidence level. The HadCRUT3v (variance adjusted version) is not recommended for this sort of analysis. The time series shows autocorrelation (i.e. residuals are not white), so the uncertainty bands should be expanded. But he does not do so. Lucia's Blackboard has a more statistically accurate analysis of whether Phil Jone's statement is accurate. Note that she is consistent in widening the uncertainty bands ..... she also routinely goes through the different possible versions of uncertainty bands in here monthly comparison of GISS and HADCRUT3 vs the IPCC AR4 projections. In those cases, the widened uncertainty bands is the only thing that keeps GISS trendline from being statistically different than the IPCC projection. 93% vs 94% vs 95% confidence factor isn't all that relevant and more likely than not, Phil Jones statement will be statistically valid in the next year or two. The "since 1995" is a cherry-picked starting point in the first place. But it is silly of him, however, to make this technically incorrect claim. -
Charlie A at 06:41 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
@#95 MoreCarbonOK "I only later picked up on a trend of no warming in the SH and more warming in the NH. You tell me why. Anyone?" The land trends are higher than the sea surface trends. SH has higher percentage of ocean, therefore is expected to have a lower trend. Land trends are higher than sea surface trends because the heat capacity of land is lower than water. -
Daniel Bailey at 06:36 AM on 16 June 2011The greenhouse effect is real: here's why
@ pbjamm I believe RSVP was sincere in his question. 394 relative to 350 is bad. 394 relative to the historical interglacial max of 298.7 is bad. Obviously yet another monthly increase is bad. Hence his question. I had hoped that May would show a tapering of the increase. -
Daniel Bailey at 06:34 AM on 16 June 2011The greenhouse effect is real: here's why
That's a good question, RSVP. May is usually the month where the seasonal peak is reached. Most years have 7 or 8 months of rise before the trees in the NH grow enough for their CO2 uptake to quell the rise and then start their seasonal drawdown of atmospheric concentrations of CO2. The fear is that enough environmental damage caused by the droughts in the Amazon, Australia, Texas & elsewhere could cause those areas to go from sinks to sources. One of the ways that could manifest itself is in the Mauna Loa monthly data. Instead of having years with 7 or 8 months of increases, we may start seeing years with 8 or 9 months of increases. I need not connect the dots for what that might imply (with the annual rates of increases themselves increasing). -
pbjamm at 06:33 AM on 16 June 2011The greenhouse effect is real: here's why
RSVP@32 Having trouble parsing this question. "...if 394 ppm is a detriment on its own right..." Is it? I am pretty sure that the concern over CO2 concentrations has nothing to do with fear of suffocation and everything to do with climate change. -
RSVP at 06:24 AM on 16 June 2011The greenhouse effect is real: here's why
Daniel Bailey 31 Why exactly a concern for global warming when the change of global CO2 ppm is already bad enough? In other words, if 394 ppm is a detriment on its own right, what does correlating this to climate change bring to table? -
Daniel Bailey at 06:22 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
@ Dikran I think we're in close agreement here. No matter the answer Jones gave, it was going to be spun out of context. My point I was trying to make (poorly) was that in not addressing the framing of the question immediately, anything that followed would be playing into the hands of the denialarati. That was the fallacy (perhaps there's a better word?). Thus, following a normal scientific response to a question given, the outcome had a predictable end. (It was essentially one of those "So, how long has it been since you stopped beating your wife?" questions) -
michael sweet at 05:37 AM on 16 June 2011Speaking science to climate policy
The aerosols are Hansen's Faustian Bargian. Hansen estimates the forcing as -1.3 W/m2. According to Bart's 0.8 C/W/m2 @3, that is over 1C of committed warming in addition to what is in the pipeline due to ocean thermal inertia. As dmccubbi says, they have a residence time of only a few days or weeks. They are continually renewed (they are one of the major components of the asian brown cloud and acid rain in the US Northeast). When they are cleaned up (eventually they must be cleaned up) the climate forcing will immediately increase. The bargain is that the aerosol pollution today will keep temperatures from rising untill the aerosols are no longer released. This committed warming is hidden for the present. -
Albatross at 05:37 AM on 16 June 2011It's the sun
Sigh, Let Tamino know...probably another crank paper that needs to be refuted. -
Bob Lacatena at 05:32 AM on 16 June 2011It's the sun
826, Tor B, Until his work is published in its entirety, and available to all, it is only so much blather, and very unlikely to undergo scrutiny, since no one else to date has been able to accomplish what he claims, and quite to the contrary, a number of existing studies demonstrate the opposite. [See the #2 denial argument, It's the Sun.] At this point, all you can do is to claim that he claims that he's submitted the masterful diagnosis which overturns all of modern climate science. Forgive me if I don't sit up too straight in my chair. At the same time, he will also need to explain other things, like why CO2 is not causing any warming (considering that the mechanism is very well understood, and it would be a huge surprise if that mechanism is totally and completely misunderstood by all atmospheric physicists around the globe). Sorry, but your post is only so much "trust me, I know a guy who knows the truth, just wait" hand waving, and as such is a wholly inappropriate claim to make. -
Rob Honeycutt at 05:19 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
JMurphy... You're right. They absolutely would have spun the whole thing the way they wanted regardless of what Jones said. But, by opening his answer with the word "yes" he basically loaded their weapons for them. -
Dikran Marsupial at 05:08 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Daniel, the question isn't a fallacy, it is actually a perfectly reasonable question, it is the implicit conclusion that global warming is not happening that is a fallacy, but that was unsaid and was made afterwards by the "skeptic" media. -
Riccardo at 05:00 AM on 16 June 2011It's the sun
Thanks DB. Actually there's not much there either, only a figure more. Assuming that it can not simply be "solar forcing integration", we need to know more about his model before commenting. And sure I'd not be thrilled by a "mathurbation". -
shoyemore at 04:49 AM on 16 June 2011The Planetary Greenhouse Engine Revisited
This is good. Best explanation I have seen of pressure broadening, whic is important to explain why band saturation is not occurring for CO2 absorption wavelengths. -
Utahn at 04:48 AM on 16 June 2011There's no room for a climate of denial
Probably too late for this thread but thought I'd post anyways: Norman: "How many consensus views in the Medical field have been overturned? Consensus views of 'experts' in their field have been overturned and wrong." I'm in that field, and I think it's actually not that often that true consensus views get overturned. A bigger problem is that a few hypothesis-generating retrospective papers come out suggesting some effect of a medication or intervention and the media overhype the results. Then later more scientifically valid prospective papers overturn what was never really a "scientific" consensus (estrogen for heart attack prevention is an example that comes to mind). Anyways, back on topic, I think we don't often discuss in the context of the psychology of denial, the prerequisite that that which is being denied must be so disturbing as to threaten a core belief or understanding. In the medical field you may often come across a patient who denies that they have hypertension because it is a threat to their core perception that they are "healthy" or "not the kind of person who needs medication". In cancer patients, denial of a potentially fatal cancer may occur due to the threat to our belief we are "healthy", but also because of the threat to our belief that we will not die. Often these forms of denial come in the form of minimizing the threat, as the evidence of a problem may be too obvious to deny. I think because we don't like to talk about politics, we often don't discuss the core beliefs threatened by climate change. In my opinion and in that of many others, this threatened core belief usually centers around a strong faith in the free market. But other threatened beliefs I think can also be involved "I'm not a polluter" being one. I hope these underlying threatened core beliefs that lead to denial are addressed in John's book that I plan to read, because I know that without addressing these in the medical field, denial is pretty hard to beat... -
dmccubbi at 04:46 AM on 16 June 2011Speaking science to climate policy
The residence time for aerosols depends, I think, on where the aerosols are located. Sulfates from volcanic eruptions can end up in the stratosphere, and stay there for a few months or years. Aersols from non-volcanic sources (dust, sulfates, nitrates, organic aerosols, black carbon, etc) stay in the lower atmosphere on the order of days. -
JMurphy at 04:26 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
I think Phil Jones gave an answer which was correct, easily understandable and honest. The fact that those in denial used a version of his answer to try to claim things that Phil Jones did not mean or say ("Global Warming in Last 15 Years Insignificant, U.K.'s Top Climate Scientist Admits" from FOX NEWS, and "Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995" from the DAILY MAIL - both headlines are demonstrably false), simply shows how despicable and dishonest they are. No matter how Jones had answered, his words would still have been twisted and abused. Don't have a go at Jones for being naive, credulous or whatever - his answer would never have been perfect enough to have disallowed its use as propaganda by those who thrive on disinformation. Have a go at those who misuse and misinform. -
Riccardo at 04:11 AM on 16 June 2011It's the sun
I don't know what's going around the intertubes, I couldn't find the paper. Maybe people is talking about nothing. We'll see.Response:[DB] Try Stockwell's blog here.
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Rob Honeycutt at 04:05 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
To back up Daniel here... This is all just the nature of language and communication. How we structure our language is part of everyday life for all of us. Politicians use techniques to dodge questions in order to not answer them. I think what Daniel, Dana and I are suggesting is it's important to dodge the "trap" when a question is structured in a way that's intended for such a purpose. But also, follow that with a full and complete answer to the question. Phil Jones could clearly have answered the question in full without falling for the trap. I think Dr. Jones' Achilles heel is that he so much of a scientist that he answered the question in a manner, as Dana suggested, that addressed a scientific audience. Any scientist listening to his words knew exactly what he meant. The general public did not. And that was the trap. -
KR at 03:54 AM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Karamanski - Lower temperature ranges in the tropics (warm all year around) mean that any increase in average temperature will exceed the ranges faster than will happen at the poles. Arctic summer temperatures are somewhere around −10 to +10°C (20°C range). Fiji, on the other hand, has a temperature range of about 27 to 31°C (4°C range). So a 2°C rise in temperature in Fiji will make averages exceed current maxes, while it would take at least ~5°C for that to happen in the Arctic. The tropics don't heat as fast as the poles, but they don't have to for average temperatures to exceed all extremes. And tropical biota are much less adapted to temperature changes - this is going to be a serious stress on the tropical biosphere. -
Tor B at 03:50 AM on 16 June 2011It's the sun
I read the following from comment #997 in Jeff Master’s blog today. I expect that someone with knowledge will have to pick his writing apart, as an article is making the rounds on the intertubes, apparantly based on Stockwell's writing. What follows is comment #997: Another blow to the AGW theory... Dr. David Stockwell who has a PhD in Environmental Sciences submitted a recent paper, that shows that solar activity alone, could explain Global Warming. I believe that GCC has more of an impact than the sun, but it's interesting nonetheless. Quote: Finally, my hibernation of the last 6 months is coming to an end, with the formal submission to a journal yesterday of the fruits of my labor. The main points: 1. solar forcing is time-integrated and not direct, 2. accumulation of the 0.1W/m2 increase in solar irradiance in the 20th century explains global warming, 3. there is a credible explanation for global warming that does not involve increases in human emissions of greenhouse gasses. Figure: Cumulative solar irradiance (blue) and volcanic forcing (red) is highly correlated with HadCRU global temperature and explains the trend in temperature since 1950. The direct solar irradiance (orange) is uncorrelated with temperature. There are a lot of other points about the model that no doubt I will get into in time. For the moment, here is the Conclusion. Contrary to the consensus view, the historic temperature record displays high sensitivity to solar variations when related by slow equilibration dynamics. A range of results suggest that incorrect specification of the relationship between forcings and temperature may be at the heart of previous studies finding low correlations of solar variation to temperature. The accumulation model is a credible alternative mechanism for explaining both paleoclimatic temperature variability and present-day warming without recourse to increases in heat-trapping gases produced by human activities. The grounds on which a solar explanation for late 20th century warming is dismissed should be reconsidered. -
Daniel Bailey at 03:50 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
@ Dikran: I'm not advocating to speak as a politician, but to first establish control of the narrative, then expose the question for the fallacy it is and to then give the actual answer with appropriate context to make it a teaching moment. But the initial sentence used is key, as it sets the stage for establishing control of the narrative to be played out. That initial response by Jones is the area of opportunity to seize control of a bad situation and to establish a more appropriate response. A good defense is to establish a counteroffensive which also dictates the terms of the engagement. Answering the question without reframing it is to engage at a disadvantage: the battle may ultimately be won but the campaign itself is lost. -
Dikran Marsupial at 03:30 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Philippe Chantreau IMHO that is exactly why few people would trust a politician further than they could throw them, the last thing scientists should do is follow in their footsteps! -
Philippe Chantreau at 03:27 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Right Daniel, that's exactly what politicians do. Politicians have been exposed over the years to lots of actually good journalism, faced with questions to which they did not have a good answer, or no answer at all. They learned these methods to cope with it and come out at the end saying many words that add up to no meaning. It is rather ironic that now these methods should be used by honest people having to answer dishonest questions, but perhaps scientists should start familiarizing themselves with it, less their words be bent in endless twists of deception. -
Tom Curtis at 03:22 AM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Karaminski @43, see my final paragraph in 6 above. -
Albatross at 03:05 AM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
For those discussing the expected impact of a solar min on global temperature, please continue the discussion here ("What would happen if the sun fell to Maunder Minimum levels?"). -
Karamanski at 02:57 AM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
"According to both the climate model analysis and the historical weather data, the tropics are heating up the fastest. "We find that the most immediate increase in extreme seasonal heat occurs in the tropics..." The finding that the tropics are warming up the fastest seems to run counter to the fact that the polar regions are warming up faster than any region on the planet. It doesn't make much sense why the tropics would heat up faster than the mid-lattitudes. Does anyone have an explanation for this? -
Eric the Red at 02:56 AM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Exactly Sky, If we experience a deep solar minimum, then the influence of solar activity can be put to rest. Since solar activity increased for much of the last century, its influences has not been satisfactorily dismissed. I am not sure why you are so quick to dispute decadal oscillations though. Especially since paragraph one indicates that solar influences are minimal, but paragraph two says that a deep solar minimum is significant. Yes, the background continues to rise. But the rise is very bumpy, and if we can identify the bumps (at least the larger ones), then we can more accurate make forecasts. -
Daniel Bailey at 02:13 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
FWIW, I would have answered something like this: "That's an interesting question, and let me tell you why it's an interesting question..." First align with the questioner, then differentiate to reveal the fallacy of the question. -
les at 02:11 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
121 - Rob Honeycutt Thanks. I really was at a loss to see what MoreCarbonOK was trying to say. You seem to have been able to read his posts better than me. -
dana1981 at 02:07 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Exactly Rob - the question was fed to Jones in a way to get him to answer "yes". As soon as he did, the "skeptics" got all they needed, as we saw from Fox News, Daily Mail, etc. I sympathize with Jones, because when I'm asked a yes or no question, I tend to answer yes or no and then clarify with the "but" if necessary. So like I said, my initial reaction would have been to respond the same way as Jones did. But when the question is being asked to trap you into a specific answer, you have to think outside the box and find a different way to answer it. And it's tricky, because scientists aren't normally asked loaded questions like that. Hence the need for media training. -
skywatcher at 02:06 AM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Deep solar minimuam and continued temperature rise = solar activity is less important in climate issues. Nobody in their right mind would eliminate it entirely from the list of climate forcings. That would be foolish and naive, and is not what climate science is all about. Dreams of oscillations in the climate of the past 100 years, created using an eyecrometer on the wiggles in the rising temperature curve inevitably have a bad ending - they are, as Tamino observes, mathturbation. Each wiggle has it's own cause - aerosols in the 1960s, deep solar minima now and early in the 20th century for example, and the sume effect on the temperature curve is to make some think of an oscillation that isn't really there. Seeing as the background continues to rise steadily, summers and winters will be much hotter soon enough, and no fantasy oscillation will help the cause. -
Rob Honeycutt at 01:56 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Dana... You're totally right. I imagine Jones was torn between being accurate and feeling trapped by the question. I think he should have lead with a comment suggesting it's a misleading question. From the moment Jones said, "Yes. But only just." People only heard the word "Yes." Everything after that was just trying to climb out of the pit he'd fallen into. Better to point at the pit first, side step it, explain why it's a pit and then answer the question as accurately as possible. Hindsight 20/20. I can't find the link at the moment but the recent John Abraham radio interview was a very good example of side stepping the traps and accurately explaining the science. -
Rob Honeycutt at 01:44 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
moreCarbonOK.... Reading through your comments here and looking through your site I believe I see most of your sources of information seem to be restricted to JoNova, WUWT, Monte Heib and others. With all due respect, you seem to be actively searching for sources that confirm what you want to believe. You've pieced together, for yourself, the same narrative being propagated by a very active anti-science crowd of people. The material you're putting together may feel right to you, it may be what you want to believe, it may sound very compelling to you. It's not science. It's not accurate. If you were truly skeptical you would take the time to try to learn what the actual scientific research says. The reason I've come to trust this particular blog (SkS) over many others is that it provides citations to actual research. Research that I go read for myself. In that I don't have to trust John Cook or any of the other authors here. I can be skeptical of even their claims. But they give me the opportunity to go to the source of the information and see for myself if their claims are accurate. I would urge you to try to do the same with JoNova, WUWT and others. I think you'll find that they mostly stick to referencing each other, not the published research. I suggest being skeptical of your own position. I try to do the same with my position every day. -
dana1981 at 01:35 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
I just think you have to keep the audience in mind. In a BBC interview, the audience is the general public. With that audience, you don't want to give a technical answer which is heavy on statistics and requires diagrams and several pages of text. Jones' answer was good if his audience was full of scientists and statisticians. I understand why Jones answered the way he did, and without giving it a lot of consideration before answering, I probably would have said "yes, but..." just like he did. But that's a mistake. I think you have to answer that question by explaining what's wrong with the question. You can't play into their trap by feeding them the answer they want. I think Jones should have used it as a teaching moment. "Well, here's why we look at temperature changes over periods of 20-30 years, and why 15 years is too short..." Then you can explain that it's not surprising why the 15 year trend is statistically insignificant, because you've already established that it's simply too short of a timeframe. As has been suggested, knowing how to properly answer this question probably requires some media training - learning how to communicate with the general public, who don't know what "statistically significant" means. -
KR at 01:27 AM on 16 June 2011Examining Dr. John Christy's Global Warming Skepticism
jonicol - In regards to the CO2 specifics you raised in your post @52, I would suggest reading (and querying/commenting upon) the There's no tropospheric hot spot thread. -
dana1981 at 01:25 AM on 16 June 2011Speaking science to climate policy
I like this article, except for the comment that we're committed to another third of a degree warming. It's twice that, and as bart notes, even more once atmospheric aerosols are reduced. But the comments about risk thresholds and needing to cut emissions immediately are spot on. Bern - aerosols have a very short atmospheric residence time, just a couple of years I believe. As we reduce aerosol emissions, atmospheric concentrations will drop rapidly. If you just consider GHGs and ignore the aerosol forcing, that gives the upper bound for committed warming. That's bart's 2.4°C from current GHG levels, although technically it's not an upper bound because he's using the most likely climate sensitivity value (3°C), not the upper bound (4.5°C or more). -
Daniel Bailey at 01:22 AM on 16 June 2011The greenhouse effect is real: here's why
Speaking of CO2, the May Mauna Loa data is out: 394.16
[Source]
No "bend" visible in the trend yet, so let's all hope that June won't continue the upward arc...
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Albatross at 01:19 AM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
To get back on topic, Tamino has a very interesting discussion on the Diffenbaugh research, and explains why the departures from hitherto natural variability is expected to occur in the tropics first. Recommended reading for all interested in this post. Note: And Eric, IIRC no-one here, and certainly not the science cited in the IPCC reports is dismissing "every other climate forcing". You are tearing down a strawman that you have created...well done, and please reply to this on an appropriate thread. -
KR at 01:16 AM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Dikran - "I don't mean to be argumentative, it is just that Jones did a very good job of dealing with this very difficult question. I don't think I could have done any better without the use of diagrams and a page or two of text." I agree. I find it extremely difficult to talk without a whiteboard sometimes.
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