WUWT readers may recall yesterday where Dr. Mann was so eager to list this paper on his resume/CV, he broke the embargo set for 15:00 EST June 20th, today, at which time this blog post appears.
As much as this is an editorial target rich environment, I’m going to publish this press release and paper sans any editorial comment. There’s plenty of time for that later. Let’s all just take it in first. Below, figure 2 from the Kemp et al 2011 paper. It should look familiar. Note the reference in Figure 2 to GIA (Glacial Isostatic Adjustment) adjusted sea level data, which has recently been the subject of controversy, it was first noted here on WUWT.
First the press release:
Contact: Evan Lerner
215-573-6604
Penn researchers link fastest sea-level rise in 2 millennia to increasing temperatures
PHILADELPHIA — An international research team including University of Pennsylvania scientists has shown that the rate of sea-level rise along the U.S. Atlantic coast is greater now than at any time in the past 2,000 years and that there is a consistent link between changes in global mean surface temperature and sea level.
The research was conducted by members of the Department of Earth and Environmental Science in Penn’s School of Arts and Science: Benjamin Horton, associate professor and director of the Sea Level Research Laboratory, and postdoctoral fellow Andrew Kemp, now at Yale University’s Climate and Energy Institute.
Their work will be published in the journal Proceedings of the National Academy of Sciences on June 20.
“Sea-level rise is a potentially disastrous outcome of climate change, as rising temperatures melt land-based ice and warm ocean waters,” Horton said.
“Scenarios of future rise are dependent upon understanding the response of sea level to climate changes. Accurate estimates of past sea-level variability provide a context for such projections,” Kemp said.
In the new study, researchers provided the first continuous sea-level reconstruction for the past 2,000 years and compared variations in global temperature to changes in sea level during this time period.
The team found that sea level was relatively stable from 200 B.C. to 1,000 A.D. During a warm climate period beginning in the 11th century known as the Medieval Climate Anomaly, sea level rose by about half a millimeter per year for 400 years. There was then a second period of stable sea level associated with a cooler period, known as the Little Ice Age, which persisted until the late 19th century. Since the late 19th century, however, sea level has risen by more than 2 millimeters per year on average, which is the steepest rate for more than 2,100 years.
To reconstruct sea level, the research team used microfossils called foraminifera preserved in sediment cores from coastal salt marshes in North Carolina. The age of these cores was estimated using radiocarbon dating and several complementary techniques.
To ensure the validity of their approach, the team members confirmed their reconstructions against tide-gauge measurements from North Carolina for the past 80 years and global tide-gauge records for the past 300 years. A second reconstruction from Massachusetts confirmed their findings. The records were also corrected for contributions to sea-level rise made by vertical land movements.
The team’s research shows that the reconstructed changes in sea level during the past millennium are consistent with past global temperatures and can be described using a model relating the rate of sea-level rise to global temperature.
“The data from the past help to calibrate our model and will improve sea-level rise projections under scenarios of future temperature rise,” research team member Stefan Rahmstorf said.
In addition to Horton and Kemp, the research was conducted by Jeffrey Donnelly of the Woods Hole Oceanographic Institution, Michael Mann of Pennsylvania State University, Martin Vermeer of Finland’s Aalto University School of Engineering in Finland and Rahmstorf of Germany’s Potsdam Institute for Climate Impact Research.
Support for this research was provided by the National Science Foundation, the National Oceanic and Atmospheric Administration, United States Geological Survey, the Academy of Finland, the European Science Foundation through European Cooperation in Science and Technology and the University of Pennsylvania.
===================================================================
Here’s the abstract:
Climate related sea-level variations over the past two millennia
Andrew C. Kempa,b, Benjamin P. Hortona,1, Jeffrey P. Donnellyc, Michael E. Mannd,
Martin Vermeere, and Stefan Rahmstorff
We present new sea-level reconstructions for the past 2100 y based on salt-marsh sedimentary sequences from the US Atlantic coast. The data from North Carolina reveal four phases of persistent sea-level change after correction for glacial isostatic adjustment.
Sea level was stable from at least BC 100 until AD 950. Sea level then increased for 400 y at a rate of 0.6 mm/y, followed by a further period of stable, or slightly falling, sea level that persisted until the late 19th century. Since then, sea level has risen at an average rate of 2.1 mm/y, representing the steepest century-scale increase of the past two millennia. This rate was initiated between AD 1865 and 1892. Using an extended semiempirical modeling approach, we show that these sea-level changes are consistent with global
temperature for at least the past millennium.
======================================================================
Figure 1: Two points in salt Marshes in North Carolina are used as the basis for the study:
Materials and Methods
Sea level in North Carolina was reconstructed using transfer functions relating the distribution of salt-marsh foraminifera to tidal elevation (7, 12). Application of transfer functions to samples from two cores (at sites 120 km apart) of salt-marsh sediment provided estimates of PME with uncertainties of <0.1 m. For each core a probabilistic age-depth model (10) was developed from composite chronological results and allowed the age of any sample to be estimated with 95% confidence. In Massachusetts, plant macrofossils preserved in salt-marsh sediment overlying a glacial erratic, were dated using AMS 14C and pollen and pollution chronohorizons (Fig. S1). The modern distribution of common salt-marsh plants was used to estimate PME. Sea level was reconstructed by subtracting estimated PME from measured sample altitude. Corrections for GIA were estimated from local (13) and US Atlantic coast (15) databases of late Holocene sea-level index points. Detailed methods are presented in SI Text.
======================================================================
They compare data at points around the world to the new SL hockey stick (in pink in the background):
======================================================================
Conclusions
We have presented a unique, high-resolution sea-level reconstruction developed using salt-marsh sediments for the last 2100 y from the US Atlantic coast. Post-AD 1000, these sea-level reconstructions are compatible with reconstructions of global temperature, assuming a linear relation between temperature and the rate of sea-level rise. This consistency mutually reinforces the credibility of the temperature and sea-level reconstructions. According to our analysis, North Carolina sea level was stable
from BC 100 to AD 950. Sea level rose at a rate of 0.6 mm/y from about AD 950 to 1400 as a consequence of Medieval warmth, although there is a difference in timing when compared to other proxy sea-level records. North Carolina and other records show
sea level was stable from AD 1400 until the end of the 19th century due to cooler temperatures associated with the Little Ice Age. A second increase in the rate of sea-level rise occurred around AD 1880–1920; in North Carolina the mean rate of rise was 2.1 mm/y in response to 20th century warming. This historical rate of rise was greater than any other persistent, century-scale trend during the past 2100 y.
========================================================================
The full paper is available here: PNAS_Kemp-etal_2011_Sea_level_rise
John B : There are a number of ways in which I, and others obviously, think that your reasoning is incorrect. I would also add that I think your emphasis is misdirected at an apparent failure of commenters to correct a minor error, especially since that particular point had already been answered by others. eg. http://wattsupwiththat.com/2011/06/20/manns-new-sea-level-hockey-stick-paper/#comment-685610
I would like to comment on your points 4 and 5 in http://wattsupwiththat.com/2011/06/20/manns-new-sea-level-hockey-stick-paper/#comment-685904:
“4. I think the reason for only going up to 2000 has more to do with the kind of data they were using than any wish to “hide the decline”. I think that for two reasons. Firstly, the flattening of the last 10 years would hardly even show up on the results, so why hide it? Secondly, if it had been technically possible to include the last 10 years, I am sure they would have done so to head off the kind of criticisms they are receiving here. I could be wrong.”
The problem is that Mann has cherry-picking “form”, so this kind of defence will carry little weight here. Especially as there was other blatant cherry-picking, as pointed out by others here.
I do agree with you that that “the flattening of the last 10 years” is not needed. Look at figures 2(B) and 2(C), and you can see two things very clearly (I am not the first to point this out): (1) The sea-level rise started before 1900. See the last “change point” in 2(C), also clearly visible in 2(B). It could not have been caused by man-made CO2. (2) The sea-level rise started flattening around 1980. This is clearly visible in 2(B). If man-made CO2 were the cause, the rise would have been maintained or accelerating.
“5. I repeat my question: Why don’t you call each other when your buddies post nonsense? Some of you are scientists, I think. You may disagree about the extent and certainty levels of AGW, but you must cringe at some of the satements made here, particularly the “argument from incredulity”, as in “I don’t understand X, so X cannot be true”, where X might be “a trace gas having a measurable effect” or “CO2 being both a feedback and a forcing”. These scientific principles were discovered way before Michael Mann and the IPCC, and the scientists among you know that.”
Yes, I do cringe sometimes. Sometimes I comment accordingly, sometimes others do, and sometimes I just let it go through to the keeper because there are more important things to comment on, or more important things for my time. The issues of real importance are that this whole man-made global warming hypothesis (MMAGW) is based on computer modelling which when analysed is highly suspect, and which is disproved in many very important ways by actual evidence. [The Mann sea-level graph I mention in this comment is just one of many examples]. The frustration that I and I am sure many others feel comes from the refusal of the supporters of MMAGW to acknowledge the evidence, their success in intimidating and demonising those who try to draw attention to it, and their influence on the media and on politicians.
I am hopeful that this is about to change, but the developed world is now on the verge of serious damage – some parts such as Spain have already suffered serious damage – and like Waterloo it could be a close-run thing.
@Mike Jonas
Thank you for your polite and well reasoned response. I would differ with you on one vtially important point, though. MMAGW (to use your term) is not based on modeling. It uses models, because they are useful tools, but it is based on the following:
1. Physical theory (Arrhenius onwards) predicts that increasesd GHGs will cause an energy imbalance, which will in turn cause warming
2. That warming has been observed, as have indirect effects of it (e.g. sea level rise)
3. The observed effects correlate with the predicted “fingerprints” of emissions of GHGs
4. The observed effects do not correlate with any other plausible effect (e.g. the correlation with solar output breaks down in about the last 40 years)
It is a myth that it is all based on models
John B:
At June 21, 2011 at 12:22 pm you say to Smokey,
“Sorry, I apologise, this time it was Richard calling me names.”
Say what!
The only “names” I “called you” were my saying (at June 21, 2011 at 6:45 am);
“Firstly, as you admit (in the same post) you are considered as being a resident troll by people who often debate in threads of WUWT. Hence, you are ignored (indeed, your post that I am complains at Bob Tisdale failing to count your posts as troll ‘invasion’).”
And I again used the phrase “resident troll” in my concluding paragraph.
Please note that I was replying to your post at June 21, 2011 at 4:25 am where you asked Bob Tisdale;
“Should I be pleased you no longer consider me a troll?”
in respose to him having said he saw no comments from trolls in the thread.
I was replying to your post that complained at your not having been listed as a troll. So, I applied simple courtesy by using the title you had claimed for yourself in your post which I answered. That is not “name calling”.
Richard
John B,
1. Arrhenius recanted his 1896 paper in a 1906 paper that drastically reduced putative sensitivity to CO2.
2. Steric sea level rise [due to thermal expansion] is falling rapidly. The decline in global temperatures over the past two years matches it. Where is your god now?
3. The models repeatedly predicted a tropospheric hot spot; the “fingerprint of AGW”. That was another wrong prediction.
4. That’s the alarmists’ constantly used Argumentum ad Ignorantium. “Since we can’t figure out the causes of natural variability, then the observed variability must be due to CO2.” As if.
And CAGW is, in fact, based on models, not empirical evidence…
Because there is no evidence!
A quick question, asked from ignorance, for the more learned here. I understand the aim of the various calculations of sea level rise are to indicate that sea levels are indeed rising. AGW theory suggests that as ice melts and temps rise, the sea level must rise accordingly, hence the dangers of land being flooded. Ignoring for a moment what might happen if sea levels DID rise by a metre or more, the thing i am most curious about is what is actually happening.
In which case, is not the raw unadjusted tide guage data what we want to see? It’s not especially relevant at a local level what the sea level is doing on average globally against some standard benchmark (incidentally, what IS sea level measured against?). Rather, what my local guage shows over the course of the past 50 years is exactly what has happened relative to my physical location. In other words, if the tide guage shows that high tide now is several millimetres higher than it was in say 1940, then clearly at my location, something is happening. If we observe the rate of that rise to be increasing, then on balance something out of the ordinary is happening.
So, what is the situation for raw unadjjusted tide guage data around the world for the past 50 years? or is that not at all relevant?
I left a comment on Real Climate asking how do you know if you are measuring sea level changes or land level changes? It was removed by the moderators, obviously not a question they wanted to address.
Another question to ask, in addition to the land mass elevation change, is what are the sea floor elevation changes?
[snip -over the top – Anthony]
Correct me if I’m wrong, but aren’t subsidence rates calculated from comparison of land and sea levels? Isn’t Mann in the end measuring that during last 2000 years, sea level was at … sea level?
John B says: The man-made global warming hypothesis “is not based on modeling. It uses models, because they are useful tools, but it is based on the following:
1. Physical theory (Arrhenius onwards) predicts that increasesd GHGs will cause an energy imbalance, which will in turn cause warming
2. That warming has been observed, as have indirect effects of it (e.g. sea level rise)
3. The observed effects correlate with the predicted “fingerprints” of emissions of GHGs
4. The observed effects do not correlate with any other plausible effect (e.g. the correlation with solar output breaks down in about the last 40 years)”
Smokey has already given a reasonably precise answer, but I’ll add my 2p (or 2c).
1. Arrhenius did indeed put forward that theory. You will be hard pressed to find many sceptics who dispute it. More below.
2. Warming was indeed observed in the latter part of the 20th century, but no-one has succeeded in proving that man-made CO2 was the cause. I will make it easier for you by stating that I am reasonably satisfied that the observed increase in atmospheric CO2 in this period was largely man-made (others may disagree), and that the sea-level rise is very likely because of the higher temperatures. However, there are a lot of problems with the CO2-temperature link: The warming in late 20thC went for about 30 years, and appears to have stopped. This tallies well with a warm PDO phase, meaning that the observed global warming was more likely to have been related to the PDO than CO2. There have been many periods of warming which have clearly not been caused by CO2, the latest being in the first half of 20thC, where the warming was very similar to the latest warming..
3. I am not sure what you mean by GHG “fingerprints“. The main “fingerprint” that I am aware of is shown in the IPCC report in Fig 9.1(c). The basic hypothesis (which, incidentally, is not explained in the IPCC report, something which I find remarkable) is that sunlight passes through the atmosphere and warms Earth’s surface. From there it is radiated as IR, which is partially intercepted by GHGs while the rest escapes to space. Man-made CO2 causes an increase in the interception of IR, and hence causes Earth to lose less energy, and hence causes global warming. The place where this process mostly occurs is in the troposphere over the tropics, as is clearly shown in IPCC report AR4 Fig 9.1(c) and (f). A very reasonable test of the hypothesis is therefore to compare the rate of change of temperature in the tropical troposphere with that at the surface. If the troposphere warms more, then the hypothesis is verified (NB. not proved), but if the surface warms more, then the hypothesis is disproved. Others (Roy Spencer, eg) have done more sophisticated analyses than me, and found the hypothesis disproved, but FWIW here is my simple analysis:
http://members.westnet.com.au/jonas1/TropicalTroposphereTemperatures.jpg
These are the RSS tropical (all available data) and Hadley global temperatures (over the same period) graphed. All data was downloaded this month. The RSS are plotted as a rolling 12-month average, the Hadley as annual averages (because that was the easiest way of doing it). The main feature to my eye is that an El Nino temporarily heats the troposphere more than the surface, but that for the rest of the time the troposphere appears to warm less. [Note: El Nino is not caused by CO2]. The linear trends (MS Excel Trend()) confirm this: Mid-Troposphere 0.11 degC/decade, Lower T 0.13, surface 0.15. The further you get from the surface, the less it warms. The trends from 1987 onwards (when RSS Troposphere/Stratosphere started) are a bit more marked, in spite of the El Nino late in the period. (The stratosphere was expected to cool anyway). The implication is surely very clear : the warming starts at the surface and flows from there to the atmosphere.
4. That the observed effects do not correlate well with any plausible natural cause is no reason to suppose that they must be caused by CO2. As Smokey points out, that is an “argument from ignorance”. The observed effects do not correlate at all well with CO2 either, as I explain in 2 above. There is the additional problem of the tropical troposphere, plus a number of others that I haven’t covered (eg. the non-warming Antarctic, slowing sea-levels, etc).
There is one more point that I should cover here. man-made global warming is not based only on Arrhenius’ theory. That gives a bit less than 40% of the IPCC’s claimed warming. The rest is claimed to come from “feedbacks”. By far the largest “feedback” is from clouds – the IPCC even claims that it delivers more warming than the CO2 does in the first place. Yet for cloud feedback there is no mechanism, it comes only from computer models, as explained in the IPCC report AR4 para 8.6.2.3 : “the GCMs all predict a positive cloud feedback .. but strongly disagree on its magnitude” or in para 10.3.2.2 : “The change in mean cloud radiative forcing has been shown to have different signs in a limited number of previous modelling studies … Figure 10.11a shows globally averaged cloud radiative forcing changes for 2080 to 2099 under the A1B scenario for individual models of the data set, which have a variety of different magnitudes and even signs. The ensemble mean change is –0.6 W m–2. This range indicates that cloud feedback is still an uncertain feature of the global coupled models …”
As Smokey says “there is no evidence!“.
Graeme M:
At June 21, 2011 at 4:56 pm you ask;
“… is not the raw unadjusted tide guage data what we want to see? It’s not especially relevant at a local level what the sea level is doing on average globally against some standard benchmark (incidentally, what IS sea level measured against?). Rather, what my local guage shows over the course of the past 50 years is exactly what has happened relative to my physical location. In other words, if the tide guage shows that high tide now is several millimetres higher than it was in say 1940, then clearly at my location, something is happening. If we observe the rate of that rise to be increasing, then on balance something out of the ordinary is happening.
So, what is the situation for raw unadjjusted tide guage data around the world for the past 50 years? or is that not at all relevant?”
With respect, you answer your own questions concerning relevance.
Average sea level rise around the entire world is pertinent to assessments of recovery from the last Ice Age and considerations of putative AGW. As you suggest, it is very small (about 2 mm per year) and, therefore, has little if any relevance to relative sea level change at any individual locality in the context of a human lifetime.
At most individual places the important consideration is change to the height of the land surface relative to the centre of the Earth. This is most important because it can be much more rapid than the effect of change to average global sea level. It can be both very large andvery rapid as a result of an earthquake. Plate tectonics and recovery from the last Ice Age provide longer term (persistent) changes to the height of the land surface relative to the centre of the Earth.
An example of longer term tectonic changes is the increasing height of the Himalayas.
And Britain is an example of a change that is recovery from the last Ice Age. Scotland was loaded down by kilometers thickness of ice only 12,000 years ago. The weight of the ice pushed Scotland down and it sank towards the centre of the Earth. So, Britain tilted: Scotland went down and the SE of England rose up. But the ice melted with the end of the Ice Age about 10,000 years ago. The loading on Scotland is gone and Britain is tilting back: Scotland is ‘floating’ back up and the SE of England is sinking back down (this is an example of ‘isostatic rebound’). So, London needs increasingly expensive flood controls because it is sinking at a rate of about 3 mm per year and, therefore, has a sea level rise of about (2+3) mm per year; i.e. about 5 mm per year.
I hope this brief answer helps and is sufficient.
Richard
And there are only 2 signs available. + and -. The behaviour of the global atmosphere, in both naive and sophisticated terms, makes far more sense with strong negative feedbacks preventing any “runaway” conditions from developing, and the prime candidate for a negative feedback against GHG warming is cloud cover. Which is a strong vote for the “-” sign.
The grotesque contortions that the AGW “scientists” and their toy GHG models have to go through to make clouds hold more heat in than they block are symptomatic of the distorted assumptions they are trying to establish and salvage. They should be ignored and disregarded, the lot of them.
Smokey says:
June 21, 2011 at 4:38 pm
John B,
1. Arrhenius recanted his 1896 paper in a 1906 paper that drastically reduced putative sensitivity to CO2.
He reduced it to pretty much what is now accepted – 1.5C, 2.1 with water vapour
2. Steric sea level rise [due to thermal expansion] is falling rapidly. The decline in global temperatures over the past two years matches it. Where is your god now?
No god. Of ourse it is not rising over the last 10 years, beause temperatures have been flat(ish). But whemn temperatures ris, it rises.
3. The models repeatedly predicted a tropospheric hot spot; the “fingerprint of AGW”. That was another wrong prediction.
No, still a fingerprint of warming in from any cause, still likely measurement error, and the hotspt has now bewn measuredm, at least short term. Look it up in any mainstreram source.
4. That’s the alarmists’ constantly used Argumentum ad Ignorantium. “Since we can’t figure out the causes of natural variability, then the observed variability must be due to CO2.” As if.
Not true! The argument is that they have looked at what n”naturalk variability” would cause, and it doesn’t match reality.
And CAGW is, in fact, based on models, not empirical evidence…
Not true. Look it up in any mainstream source.
Because there is no evidence!
There is only “no evidence” if you won’t accept mainstream evidence, and you won’t. Everything you post is from well-known contrrarians, blogs, journalists, politicians. Any evidence that does not support your view, you discount. if you can’t find flaws in the science, you accuse the sientists of lying. If umpteen studies ome up with the same result, you accuse them af collusion. And then you accept a couple of photographs as “FACT”.
But you agree with everyone here, because warming is caused by ABC (Anything But C2)
Thanks Richard S for your explanation. But I was more coming from the anecdotal point of view. I am wondering what raw unadjusted tide data around the world shows. If sea level rise is a major issue, and here in Australia claims are made that we can expect rises up to a metre over the next 80 odd years, then at some point that rise must exceed the natural forces of tectonic adjustment else we wouldn’t be facing calamity. In other words, it must be VISIBLE.
Many commenters have suggested that they aren’t aware of local changes – that where they are there is no evidence of any rise over the past 50 years. So, what does raw unadjusted tide data actually show? Because that data shows the actual physical effect at that location and would show whether anecdotal evidence has any basis.
John B,
Now you’re just arguing for the sake of arguing. I produced verifiable links and you replied with your opinion. And you really shouldn’t drink before responding. Your comments are hard to read with all the errors.
Finally, I said nothing about any photographs, where did you come up with that? And claiming that “Everything you post is from well-known contrrarians, blogs, journalists, politicians” is simply wrong. I posted 3 charts: satellite data showing steric sea level change, a chart by Bill Illis showing the decline in temperature from 2010 to mid-2011 based on UAH data, and a chart from a peer reviewed [and never falsified] paper by McKitrick et. al, falsifying the GCMs that predicted the tropospheric hot spot. In response, you posted your opinion, saying I won’t accept “mainstream evidence”. Earth to John B: There is no evidence!
John B, you say “Of ourse it is not rising over the last 10 years, beause temperatures have been flat(ish). But whemn temperatures ris, it rises.”
But isn’t the AGW case that CO2 driven warming trumps natural variation? That is why we face disaster. So, at a time when CO2 continues its inexorable rise, surely we should see the same rise in temps and hence sea level? After all, CO2 has only been rising at an unnatural rate comparatively recently, and temp rises are closely correlated. That’s where the notion of AGW arises – this tight correlation.
So, what natural variation is it that now trumps the hitherto primary effect of CO2?
I stopped by RealClimate today and read Stefan’s post on the new sea level hockey stick. Towards the end of his post in the required section “Connection to Climate” he states the following:
“According to this model, the rise after about 1000 AD is due to the warm medieval temperatures and the stable sea level after 1400 AD is a consequence of the cooler “Little Ice Age” period. Then follows a steep rise associated with modern global warming.”
Does this mean that the Team now acknowledges the MWP and LIA? I don’t seem to recall that these natural climate variations featured prominently in Mann’s original hockey stick? Or did I miss something?
Reviewing Kemp et al., the paper is silent on comparison with the readily-available Amsterdam sea level data record from 1700 to 1925. The data are available on-line at http://www.psmsl.org/data/longrecords/ancill_rep.htm
Even without datum adjustment, the shape of the Kemp supplemental data is inconsistent with the Amsterdam data.
The American Council on Surveying and Mapping (ACSM) published a document in 2008 “Understanding Sea Level Change (No. 236, December) that provides an explanation of this complex subject. In particular, it explains the importance of local mean sea level in terms of its legal definition.
Graeme M said “So, what natural variation is it that now trumps the hitherto primary effect of CO2?”
Good question. Solar minimum and La Ninas certainly play a part, but 10 years is not very long. If it doesn’t start warming again soon, AGW is in trouble, but not yet. “15 years without warming” has been quoted as where the models start to look flaky. At the moment they are spot on, as long as you don’t cherry pick or distort the data.
The more I study all of this the more I worry about the good name of science, Mann really is damaging science and to what purpose, his own ego and bank balance? In that respect he is very similar to Al Gore.
Graeme M said “So, what natural variation is it that now trumps the hitherto primary effect of CO2?”
Easily. The effect of CO2 (IF any) is EASILY trumped by natural factors and variations. This was one of the most important arguments from sceptics against CO2GW. But bureaucrats did not listen to science.
If there was any significant CO2 warming effect, climate system would be very unstable without some strong limiting factors (negative feedbacks). Any small variation in global temperature would be amplified. Ocean temperatures have BIG impact on atmospheric CO2. CO2, on the other hand, very likely has no significant/measurable effect on global temperature. When you observe temporal global temperature variations (seasonal, annual and longer timescales), you can SEE how easily CO2 is trumped. Anytime the temperature wants go down, it goes down, no matter how fast the CO2 is rising at that time. It is always at the maximum “CO2 forcing” that the temperature shifts from warming to cooling and vice versa.
We can observe it now on decadal time scales. CO2 forcing is on maximum, but the temperature decelerated and started to decrease. Soon, the atmospheric CO2 will follow.
Edim said “Soon, the atmospheric CO2 will follow”. How do you figure that? I can see why you might doubt that CO2 caused the warming, but are you also doubting the the CO2 was from human emissions at all?
John B, an interesting question. Few would doubt CO2 emissions are on the rise due to human influence, but is science so accurate that it knows definitively the potential mechanisms for remediation by the total earth system? Science will always be limited by the human nervous system – the brain is not a foolproof computing device. Its tendency to seek patterns and then identify confirmatory evidence is well known. So it would not surprise me that if the agreed view is that increasing CO2 is overwhelming the earth’s natural mechanisms we should see models and evidence that demonstrate exactly that. But what if… that is simply wrong?
I doubt it, but presumably it won’t take long to see if Edim’s prediction holds, hmmm?
Graeme M said: “Science will always be limited by the human nervous system – the brain is not a foolproof computing device. Its tendency to seek patterns and then identify confirmatory evidence is well known.”
I agree, the brain seeks patterns and finds them even when they are not there, e.g. Jesus’ face in a grilled cheese sandwich. But science is all about combating that. Science, by rigorously analysing the data, tries to find the real patterns. It might look, for example, like sea level doesn’t change beause photos look the same over 50 years, or that sea level changes dramatically because the Romans had ports where it is now 10 miles inland, but science tries to look behind that and pick apart what is really happening. I go with the science every time. Maybe that is just because I am a scientist.
John B says : “10 years is not very long. If it doesn’t start warming again soon, AGW is in trouble, but not yet. “15 years without warming” has been quoted as where the models start to look flaky. At the moment they are spot on, as long as you don’t cherry pick or distort the data.”
Actually, the models look flaky for the 30 years before WWII, because the temperatures rose strongly while CO2 did not, and they look flaky for the 30 years after WWII when temperatures fell while CO2 was rising strongly. The last 10 years, together with the earlier 60-odd years, are easily enough to disprove the models, which have only managed to be on song for 30 years in a century.. I note that you have not replied to my comment http://wattsupwiththat.com/2011/06/20/manns-new-sea-level-hockey-stick-paper/#comment-686300, addressed to you, in which I explain how other physical observations also disprove the models, and how the models are built on supposition (cloud feedback).
Re cloud feedback, I suggest you read this:
http://members.westnet.com.au/jonas1/IIPCCOnClouds.pdf
The red highlighting is mine, and saves time if you want to scan through quickly.