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scaddenp at 15:40 PM on 11 June 2011Geologists and climate change denial
Actually if we were going to personal about this, then perhaps we should have look at the mathematical skills of some prominent denialist geologists. -
scaddenp at 15:35 PM on 11 June 2011Can we trust climate models?
I see your wink but I do not follow your comment at all. Care to explain? -
trunkmonkey at 15:29 PM on 11 June 2011Can we trust climate models?
Scaddenp "Why you "separating the parameters from the physics"? They are physics too." (wink)perameritizations are actually geology. -
scaddenp at 15:10 PM on 11 June 2011Geologists and climate change denial
J Bob. The point is proportion of them doing maths. I did maths papers to masters level, but the majority of my cohort only did maths in their first year. The point is that it is perfectly possible to do geology with only 1 year of maths. Its not possible to climate science with that. A fairer way to evaluate my comment would look at average maths skill in geologist versus physicists. -
Tom Curtis at 14:49 PM on 11 June 2011Christy Crock #6: Climate Sensitivity
Eric the Red @77, did you even read the abstract?"Biospheric coupling of terrestrial water and carbon fluxes: Implications for the climate system Jan Veizer, University of Ottawa (Canada) Paul R. Ferguson, University of Ottawa (Canada) Terrestrial water and carbon fluxes represent one of the largest movements of mass and energy in the Earth's outer spheres, yet the relative contributions of abiotic water vapour fluxes and those that are regulated solely by the physiology of plants remain poorly constrained. By interpreting differences in the oxygen-18 and deuterium content of precipitation and river water, it is possible to partition plant transpiration from the evaporative flux that occurs directly from soils, water bodies and plant surfaces. The methodology was applied to fifteen large watersheds in North America, South America, Africa, Australia, and New Guinea, and results show that approximately two thirds of the annual water flux from the water-limited ecosystems that are typical of higher-latitude regions can be attributed to plant transpiration. In contrast to water-limited watersheds, transpiration in high-rainfall, densely vegetated regions of the tropics represents a smaller proportion of precipitation and is relatively constant, defining a plateau in response to incident solar radiation. Estimates of water transpiration behave similar to net primary productivity, confirming that, in agreement with small-scale measurements, the terrestrial water and carbon cycles are inherently coupled via the biosphere, offering a conceptual perspective on the dynamics of energy exchange between terrestrial systems and the atmosphere, where the carbon cycle is essentially driven by solar energy via the water cycle intermediary. Ferguson, P.R. and Veizer, J. 2007. Coupling of water and carbon fluxes via the terrestrial biosphere and its significance to the Earth's climate system. Journal of Geophysical Research - Atmospheres, Vol. 112, D24S06, doi:10.1029/2007JD008431, 2007"
Now, can you explain how a study of isotope rations of oxygen and hydrogen in modern river water "supercedes" a study of temperatures through out the phanerozoic? -
Ari Jokimäki at 14:41 PM on 11 June 2011Database of peer-reviewed papers: classification problematics
The Skeptical Chymist #37: Actually, that paper seems to be peer-reviewed. It was published in this journal (paper is listed in volume 22, issue1). The "report" seems to be a reprint of the journal. -
skywatcher at 14:36 PM on 11 June 2011There's no room for a climate of denial
One should also note, with the greatest of delicacy, that Northern Ireland is not an independent country. The UK (of Great Britain and Northern Ireland) has an all-time low record of -27.2C set on three occasions, 1895, 1982 and 1995, all in the highlands of Scotland. So Masters is right, at least where the UK's national record is concerned. Masters also corrected a previous error - his earlier posting had suggested that there had been a single national low temperature record, in Guinea, but this was actually in 2009. That leaves no national cold records for 2010. I of course accept that blog posts are not necessarily the most reliable of sources, but to my knowledge Jeff Masters has proven a reasonably reliable source of information, and his post includes both original sources and caveats about the records so people can check up on them. If anyone has more up-to-date or accuarate information the please post it! Regional and local records are broken with greater frequency, due to the very variability I was describing, but national, regional and local records all show the same trend towards more extreme highs and fewer extreme lows. -
CoalGeologist at 14:26 PM on 11 June 2011Geologists and climate change denial
This discussion seems to be drifting a bit off topic, but I'll attempt to tie various issues together by observing that it has been my impression that many of my colleagues initially approached the issue of climate change from a skeptical perspective, but unwittingly slid down the slippery slope of "Denialism". In this regard, it's important to recognize the role Denialist web sites, and books such as Ian Plimer's "Heaven and Earth", have played in perpetuating misunderstanding of the scientific arguments. (One of my colleagues actually purchased numerous copies of Plimer's book to mail to his friends in an effort to convince us that AGW is a fraud. Unfortunately for him, the book taught me more about Denialism than it did about climate science.) Any sincere skeptic can potentially find out what science has to say on specific issues through web sites such as SkS. If they then remain doubtful of the validity of the prevailing view, this is what science is all about (assuming it is for legitimate reasons). At the same time, it's important to recognize the corrupting role that "cherry picking" and "affirmation of beliefs" plays in this process, and why bias is so difficult to avoid. If in an overly zealous effort to question the prevailing theory, one immerses one's self in "Denial World", and if this is all one sees day after day, it becomes easy to believe there's no valid scientific basis for AGW. There are reasonably well defined criteria to distinguish skepticism from Denialism, and continued arguments that "Denialist" is nothing but a meaningless insult become very tedious. Any sincere skeptic should acknowledge that AGW Denialism is real, and should distance themselves from it as much as possible. Unfortunately, this is a step few ardent Denialists are willing to take, as they quickly discover that outside of "Denialworld", the arguments against AGW are as thin as Arctic sea ice. I also would like to emphasize the important contributions geologists have made to science in general, and to climate science in particular. -
Albatross at 14:12 PM on 11 June 2011There's no room for a climate of denial
Eric @63, Masters did not mislead anyone-- note the date stamp of his post: "Posted by: JeffMasters, 1:25 PM GMT on November 23, 2010" The year was not over when he posted those data. Dr. Masters is a reliable source of information. I noted the single all-time record low in my post @62. But yes, I agree that everyone should be cautious about citing information from blogs, including wikipedia ;) -
dhogaza at 14:00 PM on 11 June 2011Impacts of a melting cryosphere – ice loss around the world
Interesting how it ebbs and flows.
Except, that, of course, human emissions of GHGs aren't going to ebb if you have your way. It's all "flow". At its most basic, you're arguing that since natural variation exists and has caused problems in the past, human contributions can't overwhelm natural variation, therefore there's nothing to worry about problems caused by anthropogenic GHGs. Which is a garbage argument ... -
Eric (skeptic) at 13:45 PM on 11 June 2011There's no room for a climate of denial
"Last year, Jeff Masters gave us this list of 19 countries that set national all-time high temperature records in 2010, while not one single country set an all-time low record, despite the headlines of snow in the UK, Europe and..." I see en.wikipedia.org/wiki/Winter_of_2010–2011_in_Europe Northern Ireland beating their all-time record low in 2010. Obviously does not affect your climate argument at all, but does suggest that one should not rely on blogs for detailed claims. -
Albatross at 13:19 PM on 11 June 2011There's no room for a climate of denial
Norman @57 and 58, As I said before "You will disagree I'm sure, but your failure to recognize the err of your arguments and only further enforces the OP's point." And your posts have just affirmed that. One has to look at the body of evidence from around the globe when it comes to extremes, one also has to do some pretty sophisticated statistics. There are many studies by respected scientists (Dai, Trenberth, Zwiers, Allen, Stott, Santer and many more) that have quantitatively demonstrated that extreme events are on the increase. I am happy to provide links on another thread. You claims to consider yourself a researcher, but you have not cited any publications from reputable journals to back up your claims. That is not how science works. It is very easy to convince yourself that here is not a problem when you seek out extreme events at selected locations, but as I said earlier you have to consider the body of evidence form around the globe, it is called AGW after all. For example, last year 19 countries set all time record highs, compared to only one all-time record low, not surprisingly 2010 was tied for the warmest year on record, despite a prolonged solar minimum and the onset of a strong La Nina. "As I stated earlier I think it is on topic as it explains why I am not embracing the AGW view of future disaster." Sorry but that line of thinking is not only unscientific, but foolhardy. Do not forget that AGW is very much about where we are heading should we continue to be myopic and complacent regarding the consequences of doubling or trebling CO2. We have more than enough evidence now to know that we are facing some very difficult times ahead should we continue on this path. The prudent course of action is to not deny the facts and to take action in reducing GHG emissions. Bizarre that some would like to wait until it is too late to take action, just like in the video I showed @28. "Consensus views of "experts" in their field have been overturned and wrong." But nobody has overturned the theory of AGW. Regardless, your claims about consensus are moot; what we have now with the science is consilience, which is much stronger than consensus alone. You can continue to seek out events to convince yourself that AGW is not an issue, but doing so is just reinforcing your denial. "Historical data calls into question AGW climate change" No it doesn't. -
skywatcher at 13:12 PM on 11 June 2011There's no room for a climate of denial
#59 Norman: So you think cherry-picking individual heatwaves from history disproves the radiative forcing effects of CO2? Interesting logical process you have there... Observations of extremes in climate is all about loading the dice. The globe has shown a very well-verified warming of ~0.8C in the past century. It does not mean steady year-on-year increases in maximum recorded temperatures at individual locations. If a '12' on two dice is a heatwave, and a '2' is a severe cold spell, then climate change increases your chance of rolling 12's and reduces your chances of rolling a '2'. In fact, 13's become possible (e.g. Russia last year), and soon 14's will be on the cards, but they will not happen at every location in every year. Last year, Jeff Masters gave us this list of 19 countries that set national all-time high temperature records in 2010, while not one single country set an all-time low record, despite the headlines of snow in the UK, Europe and the USA. In the linked articles is a note that 33% of countries set record highs in the last decade, while only 6% set record lows. That's loading the dice. The record lows show that, given ideal weather, cold records can be still be achieved, it's just they need more 'ideal' conditions. Next time the weather conditions are favourable in your cherry-picked locations, those heat records will probably fall too, when the dice get their chance to roll a '12', or the shiny new '13' made possible by the extra heat in the Earth's atmosphere. -
Eric the Red at 12:45 PM on 11 June 2011Christy Crock #6: Climate Sensitivity
This supercedes the Royer paper. http://www.cprm.gov.br/33IGC/1319779.html -
Tom Curtis at 12:44 PM on 11 June 2011There's no room for a climate of denial
Norman @59, before I go any further into this, what where temperatures like in the United States in 1923-4? And what where temperatures like in Marble Bar in 1934-7? -
Eric the Red at 12:33 PM on 11 June 2011Extreme weather isn't caused by global warming
According to the NOAA data posted at #52, strong (EF3+) tornadoes have generally decreased over the past few decades. Whether smaller tornadoes have incrased of simply been detected better is still up for debate. Doppler radar has identified many tornadoes which would probably not have been spotted in years past. -
Norman at 12:24 PM on 11 June 2011Extreme weather isn't caused by global warming
Thank you DB Here is one experts opinion on the matter of tornadoes and the apparent increase. More tornadoes or better detection?. Smaller tornadoes on increase, larger tornadoes may be decreasing in frequency. -
Norman at 12:06 PM on 11 June 2011There's no room for a climate of denial
[moderator trolling snipped] As I stated earlier I think it is on topic as it explains why I am not embracing the AGW view of future disaster. Daniel Bailey, even though I do not forsee a coming nightmare climate future, it does not mean the human race should not conserve and look for alternate forms of energy to power our modern lifestyles. I think burning 80 million barrels of oil daily to run inefficient transportation is very foolish. I totally agree we need to cut our waste and excess of energy. Doing nothing is a foolish position. Historical data calls into question AGW climate change.... "During a period of 160 such days from 31 October 1923 to 7 April 1924, the Australian town of Marble Bar set a world record for the most consecutive days above 100 °F (37.8 °C).[22] The 1936 North American heat wave during the Dust Bowl, followed the one of the coldest winters on record—the 1936 North American cold wave. Massive heat waves across North America were persistent in the 1930s, many mid-Atlantic/Ohio valley states recorded their highest temperatures during July 1934. The longest continuous string of 100 °F (38 °C) or higher temperatures was reached for 101 days in Yuma, Arizona during 1937 and the highest temperatures ever reached in Canada were recorded in two locations in Saskatchewan in July 1937." These extremes have not yet been surpassed. From wikipedia article on heat waves. Our fire suppression activity may very well be the cause of increased numbers and intensity of wildfires. Droughts and wet cycles, climate extremes long before AGW and very long sustained patterns. Flatline for hurricanes over time.Moderator Response: [Dikran Marsupial] Moderator trolling snipped. Do not do that again; next time I will simply delete your post. -
Norman at 11:54 AM on 11 June 2011There's no room for a climate of denial
Albatross and Tom Curtis I started my questioning of the AGW claims because of my research into historical data and this historical data is why you would consider me in "denial". I am not interested in consensus view. History has also demonstrated that consensus views are often wrong. Truth does not depend upon the number of people who believe something to be true. Only evidence to support it is valid. How many consensus views in the Medical field have been overturned? Consensus views of "experts" in their field have been overturned and wrong. -
Norman at 11:47 AM on 11 June 2011There's no room for a climate of denial
54 Albatross I guess I am none of the characters you posted in your video at #28. Actually I am not trying to push a "red herring" argument with my line of posts above. It was a response to the Daniel Bailey video post #39. Also the historical data is why I am skeptical about the future predictions of the Climate Scientists. Maybe I appear to be a man sinking into the sea yet denying what is going on around me. I like to think of myself as a researcher. I will investigate any claims made to see if they hold up to scrutiny. I am involved in my own local project to monitor evidence of global warming in my local region. I put in daily temps, previous normal high and low temps, record high and low temps into an excel sheet and calculate daily anomalies and monthly deviations from normal. -
Tom Curtis at 11:33 AM on 11 June 2011Geologists and climate change denial
Lloyd Flack @71 "denialist" may well be a term any reasonable person may take offence to, but that is not the term I used. It is also true that actual AGW deniers are also almost universally denialists as you have defined the term. That may give a certain insulting connotation to the term "denier" to those few deniers who do pursue the issue rationally, but the insult is in the association with their fellow travellers, not in the denotation of the word. If they liked the company they keep, there would be no insult. And certainly there are 'warmistas' (oh, don't you just love the subtle wit of your garden variety denier) for whom the connotation is very strong, but that does not change the denotation and that means deniers need not take insult except that they want to. I should note that the deniers invited the re-appellation by calling themselves "skeptics" who are not, as you claim, people with doubts that where arrived at by honest enquiry. In popular usage, a "skeptic" is one who doubts, without any claim about their reason for doubting. In the other common usage, a "skeptic" is one who employs doubt as a method of honest inquiry. The deniers rely on the fist definition for the legitimacy of the term but then play on the second meaning to suggest that they, and they alone apply legitimate skepticism to AGW. So, for a catch all name, I have a choice of using the term "denier" which associates, but does not accuse, deniers of using tactics they almost universally use; or I can use the term "skeptic", thereby suggesting climate scientists do not use the skeptical methodology they in fact use. Your definition does exactly that by conflating the two legitimate definitions. Employing it the deniers show exceptional hubris by defining themselves as having arrived at their opinion by honest enquiry, and beg the question as to how honest the inquiry was. -
actually thoughtful at 11:32 AM on 11 June 2011There's no room for a climate of denial
I think Eric the Red has a valid point (our memory is fuzzier the further back in time you go). Is there a study in the frequency of "natural" disasters? How about annual insurance losses (corrected for inflation and increased population density)? I think the data supports the larger point that most posters are trying to make, but the "what can you remember" approach is not particularly satisfying. I spent most of 1986 and 1987 out of civilization, so I don't remember any natural disasters in those years. But folks who lost loved ones to those disasters for sure do. -
Norman at 11:11 AM on 11 June 2011Extreme weather isn't caused by global warming
25 Tom Curtis In your last tornado graph, I have read that the increase in total number is a result of the advanced tools meteorologists have for locating tornado activity and several storm chasers to find them and confirm touchdowns.Response:[DB] "I have read"
Norman, please be advised that when making a statement such as this intended to refute someone else's comment (which itself was based on sourced, linked data) you must be prepared to then back up your statement with a verifiable link to a reliable source.
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dhogaza at 11:06 AM on 11 June 2011Geologists and climate change denial
"The way denialist is used here it is a term that a reasonable person should take offence at." This is a bit circular, though ... reasonable people aren't denialists :) -
Eric (skeptic) at 10:49 AM on 11 June 2011Extreme weather isn't caused by global warming
Tom, I would expect more tornadoes after adjusting for observation improvements. Those improvements cause most of the increase of your lower chart. The long term increase will be due to more convection and more CAPE (shown to be in a upward trend). I would not expect more strong tornadoes because of other needed ingredients: a strong jet stream for adequate storm motion and mid-level dry air for the strong downdraft (the updrafts are readily available of course). See http://www.mhartman-wx.com/fcst_tools/meso_tutorial.html for a simple explanation. The tornado season peaks well before the summer peak in heat because those other ingredients diminish in summer. The other ingredients with increase with global warming. Thus we would expect strong tornadoes earlier in the season when the jet stream is still in a more southerly position, primarily in the areas where dry air is available east of the Rockies. We would also expect strong tornadoes in northern locations where the jet stream stays stronger later in the season and dry air is still available from Canada. Weak tornadoes should increase under global warming especially earlier in the season. -
Lloyd Flack at 10:43 AM on 11 June 2011Geologists and climate change denial
Tom Curtis @68, The way denialist is used here it is a term that a reasonable person should take offence at. As it is used here it is an accusation of a lack of intellectual integrity. It is used to describe someone who is looking for ways to continue their belief that we do not have to take action to mitigate climate change rather than honestly looking at the science to see whether there is a danger. This is contrasted with a sceptic, who has doubts that were arrived at by honest enquiry. -
P. Curtis at 10:41 AM on 11 June 2011Climate Consensus on a T-shirt
I reckon that the second tshirt design would be better, speaking as a girl. It's awkward when people try to read the writing on your tshirt by staring at your chest. I'd much rather have the writing higher up. -
dhogaza at 10:34 AM on 11 June 2011Geologists and climate change denial
One other point is the use of the "denier", conservative, etc. terms to denote those who have a opposite opinion. If one is sure of their position, one does not have to use that tone. What comes across is a "methinks thou protests too much" impression, and hence has to cover a weak position.
Obviously J. Bob wasn't required to take a logic class in order to get his engineering degree. Logic fail. -
Tom Curtis at 10:15 AM on 11 June 2011Geologists and climate change denial
J Bob @68, we call the deniers "deniers". They in turn, and before hand, accuse us of being "alarmist", "fraudulent", "conspiratorial", "dictatorial", "censorous", "traitorous", and "genocidal". From this you conclude that we protest to much to hide a week position? Frankly, "denier" is not even an insult. An AGW denier is simply a person who denies AGW. In this case, that deniers take umbrage at what is a simple descriptive term shows they have a raw nerve about the quality of their arguments. -
J. Bob at 09:54 AM on 11 June 2011Geologists and climate change denial
scaddenp @ 51, I'm nor sure where you got your undergraduate degree, but the institute where I went, in the USA, there where a number of geology students in Advanced Calc., as well a sprinkling in Partial Dif. EQ. Our engineering group was also required to take a Geology course in Rheology, to expose us to "plastic" flow of materials So I would dispute you statement of a "low mathematical skill level". Now most engineer & science students may probably will not use all the tools they were taught, but at least they were exposed to a wide variety of tools, to think critically, and a significant number of lab hours, to show where theory and reality can collide. One other point is the use of the "denier", conservative, etc. terms to denote those who have a opposite opinion. If one is sure of their position, one does not have to use that tone. What comes across is a "methinks thou protests too much" impression, and hence has to cover a weak position.Response:[DB] Let's not make this personal. I'm sure the vast majority of participants here all have significant college/university degrees. Most of us have multiple degrees as well. Whoopee.
What matters is the quality and relevance of your comments and arguments.
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John Hartz at 09:48 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
@chris #71: Or scientists could use the term, "troposphere temperature sensitivity" rather than "climate sensitivity." One of the reasons why scientists have such a difficult time effectively communicating their findings to the average person is what I call "scientific shorthand-speak." -
Tom Curtis at 09:44 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
scaddenp @74, being fair to Shaviv and Veizer, they did publish a comment on Royer et al, 2004. In it they claim that Royer et al failed to take into account changes in ice volume in their calculations, and that doing so largely obviates the effect of pH in interpreting temperatures. Disappointingly, they do not publish a reconstruction based on their estimate of the effects of ice volume, and continue to use the older reconstruction without pH correction. To an abbreviated version of that comment, Royer et al reply, saying that their result has good geological confirmation, and that the ice volume effect is only relevant during glacial periods, when their pH correction is small. -
Tom Curtis at 09:08 AM on 11 June 2011There's no room for a climate of denial
Eric the Red @52, my point was a response to Norman's comment @46. In it he suggested that past weather events are on topic on this thread because they may be the reason for peoples denial of global warming. Logically, however, if they only remember only one or two events from any give year in the past, that cannot be their reason for concluding that 2010/11 has not been unusual. (I did not choose 1954 as a sample year, by the way, Norman did. I have discussed the US tornado record here as it is of topic on this thread. -
Tom Curtis at 09:07 AM on 11 June 2011Extreme weather isn't caused by global warming
Responding to Eric the Red: In 1954 there were 550 tornadoes, and 36 tornado related fatalities. This compares with 1039 tornadoes to June 8th, 2011, with 525 fatalities. 1974 is a much better comparison year, but there have already been 94 more US tornadoes as of June 8th than in 1974, and 159 more fatalities. With just 75 EF3 plus tornadoes to June 8th, 2011 is unlikely, as you point out, to exceed the 121 (122?) F3 tornadoes in 1974, but the switch from the Fujita scale to the extended Fujita scale makes such comparisons tricky. None of that adresses the extraordinary quantity of tornadoes in April, with 675 confirmed tornadoes, significantly more than double the amount in April of 1974:
It is also significantly more than the previous monthly record of 542 confirmed tornadoes in May, 2003:
You will, of course, notice that there is a rising trend in April tornadoes, and a stronger trend in May. So, you guessed it, there is a strong rising trend in annual tornadoes as well:
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garethman at 09:05 AM on 11 June 2011Impacts of a melting cryosphere – ice loss around the world
dhgaza. Garethman - obviously you don't understand post #16 and the inline addendum by DB Garethman Apparently the reference is with regard to your charts you posted, not mine. It’s an accurate observation it must be said. What is the comment on my chart, or should we set this to one side as being beyond the Pale? Do you think the chart I posted is inaccurate in some way? I still think your chart shows the same thing, it’s scale that is the difference. Great info though, please keep up the supply. Cheers GResponse:[DB] The point is, the focus (yours) on a short period of time in a noisy time series means...absolutely nothing. Some Most would call that a cherry-pick. The lack of any statistical analysis to support your "flattening" claim means you used the old Eyecrometer Mk 1.
A professional time series analyst examining the issue would conclude that there is indeed a clear trend. And it ain't flattening:
[Source]
Tamino has many other great pieces in just the last year. Relevant ones to this discussion include this, this, this, this, this and this.
Apologies for the information overload, but you're touching upon one of the most-studied areas in all of climate science.
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garethman at 08:48 AM on 11 June 2011Impacts of a melting cryosphere – ice loss around the world
Cheers DB, got it. -
scaddenp at 08:43 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Eric, until a new paper with new data and/or methods can show an improvement on Royer, I dont see how its possible to stick with Veizer interpretation. Reality is not a matter of opinion. If Veizer thinks Royer wrong, then there has been ample time for a response. A conversation, interpreted and reported by a well-known denier, is hardly evidence. -
michael sweet at 08:26 AM on 11 June 2011Ocean acidification: Some Winners, Many Losers
John, I have seen reefs that have degraded and slime is the correct discription. It is usually blue green algae or red slime algae. Sometimes it is hair algae, which is also slimy. If you have citations that the replacement algae is seeweed and not slime you need to present them, not assert without any evidence that seeweed is the replacement algae. Suggesting that "a few misguided coral reef scientists subjectively refer to "slime" on reefs," without citations is not a scientific argument, it is unsupported opinion. -
Tom Curtis at 08:10 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Eric the Red @59 & 62: First, your second paper is Shaviz and Veizer, 2003. It still pre-dates Royer et al, 2004; and is refuted by it. Second, below is the crucial image from Came et al, 2007, of which Veizer was one of the co-authors. It compares the two temperature records from that paper with to previous reconstructions of Phanerozoic temperatures, that by Veizer et al, 2000 (light grey) and that by by the GEOCARBIII model (as shown in the second image in my 51). Also shown along the bottom is Scotese's division of the global climate into warm and cool periods. I have added a green line for easy alignment.
It is very clear from this that Came et al, 2007 tends to confirm Royer et al's conclusions, and to disconfirm those of Veizer et al, 2000, and Shaviz and Veizer, 2003.
Having said that, Came et al examine samples from just one location and one formation from the Silurian. The GEOCARBIII model has a resolution of 10 million year, and as the recent record of glacials and interglacials shows, temperatures can fluctuate a lot in such a short period. Therefore Came et al is neither a definitive confirmation of Royer et al, nor a definitive refutation of Veizer et al. Came et al in fact take refuge in that fact to say,
"Our re-interpretation of the d18O values of Silurian and Pennsylvanian carbonate fossils also may apply to other parts of the Palaeozoic. However, there remain several marked discrepancies between climate reconstructions using the GEOCARB model versus those implied by the Scotese geological record and the Veizer et al. oxygen isotope record (which generally agree with each other, at least in timing of climate variations), and it is difficult to imagine that all time periods will be resolved in the same way as those examined in this study."
So, Veizer does not think that Royer is right; but subsequent evidence which he has contributed has tended to confirm Royer's conclusions and disconfirm Veizer's. Disappointingly, Came et al do not discuss ocean pH even once. Considering the nature of Royer et al's critique of Veizer et al, that is a glaring oversight. -
chris at 07:10 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
whoops...in my second paragraph I should say: "..and so a significant change in temperature is expected to lead to a change in climate" -
skywatcher at 07:09 AM on 11 June 2011Impacts of a melting cryosphere – ice loss around the world
#6 Your estimate may be too high, depending on both the proportion of methan e to CO2 in the carbon released, and also the shorter lifetime of methane in the atmosphere - ~12 years as opposed to hundreds of years for CO2. But I don't know the physics enough to be sure. The basic idea of extra greenhouse gases being released due to warming of the Arctic does not make happy reading however you slice it though. -
chris at 07:07 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Badgersouth at 06:22 AM on 11 June, 2011 Yes, OK; I think we have to recognise that words are shorthands for things, and that we sometimes need some informed knowledge about the meaning of a particular word or phrase in a specific context. That's a fundamental element of language - it would be cumbersome to communicate with each other if we didn't have shorthands to encapsulate more complex concepts! So yes "climate sensitivity " is a shorthand for something like "equilibrium response of the globally averaged near Earth surface temperature to a forcing equivalent to a doubling of atmospheric [CO2]". It doesn't really refer specifically to "climate" at all! However climate (which is a local property as you point out) is intimately related to the Earth's globally averaged surface temperature, and so a significant change in temperature is expected to lead to a change in temperature. So there is a connection. Obviously "climate" isn't amenable to definition with a single quantitative metric, as temperature is. So in order to usefully interpret "climate sensitivity" we need some information on the manner in which excess energy in the climate system in response to a forcing is spatially-distributed, and its consequences (on the hydrological cycles, weather systems, land ice and plant responses etc.), to assess the likely true climate responses to a change in globally averaged temperature... -
Albatross at 06:43 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Eric @62, "Many people have told me that I am "in denial" recently to entertain the thought that climate sensitivity could be closer to 2 than 3." That would be completely at odds with what Christy and Lindzen believe. Also, keep in mind that on our current path we are easily going to double CO2 levels, and may quite easily treble them. So we are very likely looking at well over 2 C warming in an incredibly short time in geological terms, and that at a time when we will likely have over 10 billion mouths to feed. -
John Hartz at 06:33 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
I suggest that every article in the Christy Crock series have a tab listing the titles of the other articles in the series with a link to each embedded in the title. -
John Hartz at 06:26 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
If Dr. James Hansen were not concerned about the negative consequences of climate change in the 21st century, he would not have written "Storms of My Grandchildren." -
John Hartz at 06:22 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
@Chris #65: Those are all good points and thank you for posting them. My frustration really stems from what I perceive to be an inconsistent use of the term "climate" among scientists. In the above discussion, the term really means "the temperature of the lower atmosphere as measured by a single metric." (Even that single metric masks all kinds of significant spatial and temporal variations within the lower atmospher during the course of a year.) If the basic definition of the Earth's "climate system" includes the atmosphere, the hydrosphere, the cyrosphere, etc., the word "climate" should not then be used to define one subcomponent of that system. -
dhogaza at 06:16 AM on 11 June 2011Impacts of a melting cryosphere – ice loss around the world
Garethman - obviously you don't understand post #16 and the inline addendum by DB. -
Bob Lacatena at 06:13 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Eric, Forgive me, but your position seems to be based entirely on a convenient form of cherry pick, but instead of cherry picking the data, you're cherry picking the one paper you want to use on which to base the all of the weight of your opinion. There are various and sundry studies, almost all pointing to high(er) climate sensitivity. You have picked one study, from 10 years ago, which is contradicted by a number of other studies, as well as the author himself, and you choose to put huge emphasis and weight on that one paper, to the point of declaring that "I disagree that the sensitivity has never been less than 2.5 or been as high as 5." Your defense of the paper comes from a blog post by someone who claims to have spoken to the author of the original and contravening studies, with hints of partisan politics pressuring him into "compromising" on the studies wording and conclusions. Is this really the skeptical approach to the science? -
chris at 05:58 AM on 11 June 2011Christy Crock #6: Climate Sensitivity
Badgersouth at 05:20 AM on 11 June, 2011 There are (at least) three reasons why the Earth surface temperature is a useful and important metric. 1. Averaged over several years [i.e. averaging the effects of seasonal variation and short term ocean surface variability (El Nino/La Nina)] the Earth's surface temperature seems to remain relatively steady in the absence of external forcing. So the averaged Earth surface temperature seems to be a decent metric for the amount of energy in the climate system, despite the various energy fluxes through the system. And so the change in the Earth surface temperature is a good metric for the change in the energy in the climate system in response to a forcing (e.g. from enhanced greenhouse forcing in response to a change in [CO2] or changes in solar output). 2. From a terrestrial perspective the Earth surface is the location of the biosphere, and that's of fundamental interest to us. The Earth surface temperature is probably the most important metric for assessing potential effects of forcings on the biosphere. 3. Partly due to 2 [the response of elements of the geosphere and biosphere to temperature changes (plant leaf stomatal responses; isotopic composition of shells, wood and ice; the spectrum of species that thrive at a particular temperature, and so on), temperature changes leave a variety of signatures in the paleo-record that allow localized surface temperatures to be reconstructed. So this metric provides a means of assessing the relationship between changes in paleo[CO2] (which also leaves a variety of signatures in the paleo-record) and temperature (aka climate sensitivity), which informs us of contemporary and future temperature changes in response to massively enhancing the Earth's greenhouse effect... -
Albatross at 05:50 AM on 11 June 2011There's no room for a climate of denial
Eric and Norman, Which characters are you in the video that I posted @28? Extreme weather events (e.g., droughts, heavy rainfall, heat waves) are on the increase, that much is objectively and quantitatively described in the reputable scientific literature. And events in the past 12 months or so are consistent with the the long-term trends documented in the literature. Anyway, thanks for continuing to provide such an excellent example of denial at work. You will disagree I'm sure, but your failure to recognize the err of your arguments and only further enforces the OP's point. Norman, "Albatross, this thread is asking why so many doubt AGW's dire predictions" Your opinion is not shared by those in the know an by climate scientists. If anything it is shared by misguided, or misinformed or conspiracy theorists. Also, you are arguing a strawman, the OP says: "However, refusing to accept the overwhelming scientific evidence is not scepticism but denial." and this "Paradoxically, as scientific evidence for human-caused climate change pours in, interest and belief in climate change within the public is on the decline." That is essentially what the OP is about, not the red herring what you are trying to push above.
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