From Steve Goddard: Thanks again to Dr. Meier from NSIDC for answering questions, and for offering to do a follow-up.
From Anthony: Responses from Dr. Meier are in italics. I’ve added a poll that you can answer after reading this. Note this poll only allows one vote per IP address. So shared IP systems at offices will only get one vote.
From Dr. Meier: Thank you to Mr. Goddard for presenting this and the previous set of questions. And thank you to Mr. Watts for providing the outlet to publish these. I don’t hope to change the opinion of every climate change skeptic who reads my responses, but hopefully I can provide some useful for information. My answers here and to the previous round of questions are my own and I am speaking for myself, not as a representative of the National Snow and Ice Data Center or the University of Colorado. Thanks to Stephanie Renfrow, Ted Scambos, Mark Serreze, and Oliver Frauenfeld of NSIDC for their input.
One thing I noticed in the comments on my previous answers was a desire for references to peer-reviewed journals. I originally chose not because I didn’t realize there might be an interest and also because a few journal articles doesn’t substantiate human-induced global warming (nor do one or a few articles refute it). It is the preponderance of evidence presented in thousands of articles that provides the foundation for the human-induced global warming theory. Nonetheless, below I provide a few selected references for those that might be interested.
There were lots of good questions from readers, and I have synthesized some of them into a few short ones here for the sake of brevity. There is no question that late-summer Arctic ice extent has declined considerably since the early 1980s, and if the current trend continues linearly – the sea ice will disappear completely at some point in the not too distant future. Most of the questions were along the lines of “how do we know the trend is non-cyclical, and how do we know what is causing it?”
1. Q: The image below shows the general GISS temperature distribution of the previous Arctic warming cycle in the 1920s and 1930s, for stations north of 60N. Turquoise dots had warming similar to the current warming. Red dots are significantly warmer now than they were 70 years ago. Looking at the map, it would be easy to come to the conclusion that the only difference between the current warming and the one 70 years ago, is that the PDO has been in it’s warm phase for the last 30 years – causing warmer temperatures around Alaska and Eastern Siberia. The PDO appears to have recently shifted to its cool phase, and temperatures across Alaska have dropped during the last two years. Why do you believe that the fundamentals of the current warming are so different? Perhaps the warming of the last 30 years was aggravated by a coincidental alignment of the PDO and AMO?
A: The warming of the last 30 years cannot be attributed primarily to the Pacific Decadal Oscillation (PDO) or the Atlantic Multidecadal Oscillation (AMO). The AMO does not have a significant influence on the Arctic. On the Atlantic, side, the North Atlantic Oscillation (NAO)-a regional expression of the Arctic Oscillation (AO)-is the most influential mode of variability in the Arctic. As I’ve mentioned previously, there are natural variations in climate that do indeed affect Arctic temperatures in the Arctic and the sea ice. The NAO/AO is a particularly prominent one and a substantial amount of the decline in the sea ice during the late 1980s and early 1990s could be attributed to a strong positive mode during winters because the positive mode favors the loss of thicker ice that is less likely to melt during summer. However, since about 1995, the AO has mainly been in a neutral or negative state. Under such conditions, the Arctic sea ice should have started to recover. Instead, sea ice extent has not only continued downward, but the decline rate has accelerated. The AO may have been a “trigger” for the precipitous decline, but we wouldn’t have the ongoing decline without the documented warming trend (Lindsay and Zhang, 2005).
The Pacific Decadal Oscillation (PDO) also can play role in temperatures in the Bering Sea region and to some extent in the Pacific side of the Arctic Ocean. The PDO was in a fairly persistent positive mode until the mid-1990s, but it also has shifted to a more neutral state and so cannot explain the decline of the Arctic sea ice since that time. (More details: Overland et al., 2004 and Overland and Wang, 2005).
Another important point is that these climate oscillations can themselves be affected by global warming. There are indications that the positive mode of the AO is more likely to be present under warmer conditions.
2. Q: Given that we don’t really understand what caused the earlier warming period, what evidence is there that the current warming is anthropogenic? How much of your viewpoint about the Arctic future is based on IPCC feedback predictions?
A: There is considerable evidence that the current warming is anthropogenic; this evidence is readily available in thousands of unrelated peer-reviewed scientific journals. You also ask how much of the evidence is “based on” IPCC predictions? In a way, the answer to that question is that none of the evidence is from the IPCC report-and yet all of it is. The reason is that the IPCC report isn’t a source of newly published information, but rather a compilation of evidence from a growing number of articles previously published in scientific journals. All of the information in the IPCC working group reports is referenced to original peer-reviewed journal articles citing researchers from around the world. Thus, the IPCC report is a convenient “one-stop shop” of the latest information, but the ultimate source is the thousands of individual international journal articles that are the basis of the report.
In the first part of your question, you suggest that a lack of understanding of earlier warming periods is a given, and that this casts doubt on our understanding of current warming. From this perspective, it might seem reasonable to assume that because previous change was natural, the current change must be too. Many natural explanations for the current observed warming have been suggested:”it’s just natural variability,” “it’s the sun,” “it’s cosmic rays,” etc. However, these have all been investigated and evidence is simply lacking.
On top of the lack of evidence for natural causes, such suggested explanations ignore the proverbial elephant in the room. Any natural-causes explanation must be accompanied by an argument for why and how human-caused greenhouse gases (GHGs) are not affecting climate in the same way that natural GHGs affect climate. This, again, has not been addressed in a reasonable way.
Here is what we know about greenhouse gases and their influence on climate:
1. Greenhouse gases absorb energy radiated by the earth that otherwise would escape to space, keeping the earth warmer than it would be without GHGs. This is a fact that has been well-known for over 100 years, described in a paper by Arrhenius (1896). GHGs are a necessary part of Earth’s natural “climate control.”
2. GHGs are increasing in the atmosphere. This is known from observations of carbon dioxide dating back to the 1950s from Mauna Loa and other stations, as well as paleo-records of GHG concentrations in ice cores.
3. The GHG increase is due to human-caused emissions. This is clear from the simple fact that we know we’re emitting GHGs through our use of fossil fuels. More scientifically, it is confirmed by a characteristic chemical signature of human-emitted GHGs found in the atmosphere.
4. GHG concentration and surface temperature are closely linked. This is clear from #1, but the relationship is confirmed in ice core records dating back several hundred thousand years. Some of your readers may have heard a suggestion that carbon dioxide lags temperature in the ice core records; that’s not relevant in this case. For more details, see here and here and here
5. The first studies of the effect of GHGs on Earth’s energy budget date back to the1950s (e.g., Revelle and Seuss, 1957). The increasing GHG emissions have already changed Earth’s energy balance. Human and natural changes have increased the radiative forcing (effectively increasing the energy, and thereby the temperature, of the Earth) by about 1.6 Watts per square meter. The largest factor by far is human GHG emissions. Changes in the sun play only a small role. This increased radiative forcing results in a warming of the planet. There is simply not enough uncertainty in these estimates to throw the overall conclusion into doubt: human-induced GHGs have changed Earth’s energy balance and increased temperatures.
FAQ 2.1 Figure 2 from IPCC Working Group I Fourth Assessment Report, 2007.
6. There are feedback mechanisms that can alter the impact of GHG emissions. These include: clouds, water vapor, ice/snow. Ice and snow are clearly positive feedbacks that will reinforce the GHG warming because as they melt, the average albedo (reflectivity) of the earth decreases and more energy is absorbed. The effect of other feedbacks is less certain-and may even counter the effects of GHG warming–but the evidence indicates that they nevertheless do not come close to offsetting the direct effect of GHG emissions.
So, before one can suggest that natural mechanisms explain everything, one has to first demonstrate that something in the above 6 points is wrong. Much of this evidence dates back to at least the 1950s; the theory of anthropogenic global warming is really nothing new. Also note that climate models only play a significant supporting role in the evidence for points 5 and 6. No serious scientific study has yet shown that any of the above 6 points are fundamentally wrong.
The only one of the 6 points still in play to any scientific extent whatsoever is the last point. There has been some interesting research in this area – Richard Lindzen’s Iris effect (a nice summary here) and more recently Roy Spencer’s “internal radiative forcing.”. Spencer’s work is quite new, and has therefore not yet been properly vetted through the peer-review process. (Some informal discussion: RealClimate.
3. Q: You mention the historical record of the Inuit. What do we know about the older historical record from the Vikings?
A: There is archaeological evidence, oral sagas, and some written records, none of which I’m an expert in. However, I can share with you what I know: The Vikings colonized Greenland during about 700-1300 AD, taking advantage of the medieval warm period (MWP). There was reduced ice cover compared to before and after that period that allowed easier sailing between Europe and Greenland. The warmer climate allowed enough farming and ranching to support the population. As climate cooled, crops failed and transport (trade) with Europe became difficult or impossible. There was clearly less sea ice during the MWP than the cool period that followed. It is not known how sea ice conditions compared to today, but ice extents comparable to the 1980s or 1990s would have been sufficient for the Vikings to have successfully sailed between Greenland, Iceland, and Scandinavia; ice would not have had to be at current low levels.
Greenland and northern Europe were clearly warm during the 700-1300 AD; much of the rest of the globe may have been as well. There is often quibbling about whether we’re warmer now than then-the Mann hockey stick plot, etc. But as I pointed out above, such “debate” is almost beside the point: it ignores the elephant in the room that is the GHG emissions produced by humans. We may not clearly know what caused the MWP, but we have a clear cause for the current warming: human-caused GHGs.
4. Q: Is there any hard data on permafrost losses during the last ten years?
A: There is clear evidence of increasing ground temperatures and thawing permafrost, consistent with the warming surface temperatures. Permafrost will respond more slowly to warming, but it is a potentially significant long-term feedback because large amounts of GHGs, particularly methane, are “locked” in the permafrost. As much GHGs are locked in the permafrost as currently resides in the atmosphere. At least some of these GHGs will be released as the permafrost thaws. There have been several papers discussing permafrost thaw and potential climate impacts (Zimov et al., 2006; Lawrence and Slater, 2005; Lawrence et al., 2008).
5. Q: Has there been a trend of the date of minimum Arctic sea ice coverage? Has there been a trend in the date of maximum Arctic sea ice coverage? If there has been warming over the ice (which is not sampled adequately), there should be an earlier maximum and later minimum.
A: There has been a trend toward later minimum dates, but there is substantial variability from year to year in the freeze-up date. A later freeze-up is not surprising because with lower summer ice extent, there is more ocean area to absorb heat that needs to be dissipated before freeze-up can begin. However, there is high variability because the timing of when the ice stops shrinking and begins growing has a lot to do with short-term weather. A late-season warm spell can extend melt, while a quick, early cold snap can cut melt short.
There is essentially no trend in the date of maximum extent. There is even greater variability from year to year in the maximum date than in the minimum date. This is also not surprising. At the time of maximum extent, the boundary of the ice edge is unconstrained and has extended into the north Atlantic and north Pacific. Ice at the ice edge is also thinner at the maximum. Most of it is less than 50 cm thick, because it is ice that has recently formed. This ice is prone to being broken up by winds, advected into warmer waters where it melts, or pushed northward. On the other hand, cold winds from the north can cool surface waters and allow more ice to form, at least temporarily, and extend the ice edge farther south. So, the ice edge location at the time of the maximum is fairly volatile and subject to sudden change. This variability can be seen in AMSR-E data graph, where you can see the bumpiness of the daily extent during the winter season. This is the ice edge “bouncing around” in response to winds, currents, storms, etc.
6. Q: Looking at the AMSR-E sea ice extent graph, I see an alternative description for recent behavior. Until the first week in August, 2008 extent was equal to or greater than 2005 – and NSIDC was even considering a possible return to normal as late as August 1. However, a series of strong storms broke up the ice and caused 2008 to drop below 2005 for a few weeks. As September ends, 2005 and 2008 appear to be converging again. Average daily ice extent in 2008 has been greater than 2005, and nearly every day in 2008 has been greater than 2007. What is wrong with this description?
A: The description is incomplete and lacks relevant context. First, all the recent years in the AMSR-E record have had anomalously low maximum extents compared to the 1980s and 1990s. Even the largest winter extent, in 2002, was 250,000 square kilometers lower than the 1979-2000 average. The years 2005-2008 have been 700,000 to 1,000,000 square kilometers below the average. As described above, there is considerable variability during the time around the maximum extent, so the difference between 2005 and 2008 is within what might be expected from natural variations, but both are lower than maximum extents during the 1980s.
While there is a lot of variability in the timing of when the maximum occurs (as mentioned in #5), the actual maximum extent has relatively low variability. This is because in winter it is cold and dark, and ice grows under those conditions. So you always see ice growth, although there is now a significant downward trend at the maximum. In comparing winter ice conditions, ice thickness is much more relevant than ice extent. Data for thickness is not as complete as it is for extent, but it is quite clear that ice is thinning at a rate even faster than the extent decline. During winter 2008, the Arctic was dominated by seasonal ice (ice that has grown since the previous summer) that is much thinner than multiyear ice (ice that has been around for at least a year). Thus, in 2008 the ice has generally been thinner than 2007, and much thinner than earlier years.
We are now seeing some rapid growth of sea ice in the Arctic as the large expanse of exposed ocean cools, but this will all be thin first-year ice. It will thicken over the winter, but by the end of the winter it will only be a half to a third as thick as the ice used to be.
Sea ice also moves with the winds and currents – it doesn’t just grow and melt in place – and thinner ice is generally more easily pushed around. Last year a lot of ice got pushed by winds across the Arctic and even less of the region was covered by thicker old ice at the end of the winter than at the beginning of the winter.
Finally NSIDC did not say that the Arctic sea ice extent would return to “normal” in 2008. The figure referenced in the question, does show one scenario where ice returns to normal, but as stated in the text, that scenario was for a slower than normal melt through the rest of the summer and was deemed highly unlikely. As we say in our August 1 entry: “Thin ice is much more vulnerable to melting completely during the summer; it seems likely that we will see a faster-than-normal rate of decline through the rest of the summer.”
7. Q: Why does NSIDC say that the 2008 minimum sea ice extent “reinforces” the long-term trend when the 2008 extent was clearly higher than 2007?
A: 2008 is in no way a “recovery” relative to the thirty-year trend-and since GHGs act over long time periods, scientists favor looking at change over a long period to detect the GHG signal. From 1979 through last year, the September monthly average extent was declining at a rate of about 72,000 square kilometers per year based on a linear trend. Calculating a linear trend of the data from 1979 through 2008, the decline is now 78,000 square kilometers per year. This may seem counterintuitive, but what happens to the trend each time you add new data depends on where the new data falls relative to the trend line. If a data point falls below the trend line, it will “pull” the trend line downward; a data point above “pulls” the trend line upward. The September 2008 extent, although a bit higher than 2007, was still well below the trend line, so the downward trend line steepened. This is what I mean when I say the trend has been reinforced. Those who attempt to claim that we’ve seen “global cooling” since 1998 may wish to bear in mind that until scientists see a change over a long period, we are skeptical of claims concerning a trend.
The key thing, whether discussing sea ice, temperatures, or any other environmental measure, is to consider long-term trends, not short-term variability.
September monthly sea ice extent and trends for 1979-2007 and 1979-2008.
References:
Arrhenius, S., 1896. On the influence of carbonic acid in the air upon the temperature of the ground, Philos Mag, 41, 237-276.
Lawrence, D. M., A. G. Slater, 2005. A projection of severe near-surface permafrost degradation during the 21st century, Geophys. Res. Lett., 32, L24401, doi:10.1029/2005GL025080.
Lawrence, D. M., A. G. Slater, R. A. Tomas, M. M. Holland, C. Deser, 2008. Accelerated Arctic land warming and permafrost degradation during rapid sea ice loss, Geophys. Res. Lett., 35, L11506, doi:10.1029/2008GL033985.
Lindsay, R.W., and J. Zhang, 2005. The thinning of Arctic sea ice, 1988-2003: Have we passed a tipping point, J. Climate, 18(22), 4879-4894, doi:10.1175/JCL13587.1.
Overland, J. E., M. C. Spillane, D. B. Percival, M. Wang, and H. O. Mofjeld, 2004. Seasonal and regional variation of pan-Arctic surface air temperature over the instrumental record, J. Climate, 17, 3263-3282.
Overland, J. E., M. Wang, 2005. The third Arctic climate pattern: 1930s and early 2000s, Geophys. Res. Lett., 32, L23808, doi:10.1029/2005GL024254.
Revelle, R., Seuss H.E., 1957. Carbon dioxide exchange between atmosphere and ocean and the question of an increase of atmospheric CO2 during past decades, Tellus, 9, 18-27.
Zimov, S.A., E.A.G. Schuur, and F.S. Chapin III, 2006. Permafrost and the global carbon budget, Science, 312, 1612-1613, doi:10.1126/science.1128908.
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Anthony, I think the post I just made was eaten by the spam filter. Could you look for it? Perhaps the problem was that I had a URL for the data source of the graph at the top of “Ice Reality Check” but I didn’t make it into an HTML link.
Phil:
3) Due to orbital changes, the temperature rise stops, and CO2 continues the warming , which produces more CO2 (See 2) which continues warming.”
4) Further orbital changes cause the temperature to drop, even while CO2 is high.”
“the temperature rise stops, and CO2 continues the warming ”
Aerm come again?
In general your hypothesis also seems to have a fundamental problem .
Both the rise and the fall of temp/CO2 is initiated by a short orbital change? When this orbital interaction is over, then the temp/CO2 interacts so that we get a further rise or fall in temp/CO2?
So.
When there is no outside orbital interaction,
1) during the rise this temp/CO2 system tends to rise all by itself?
2) during the fall this temp/CO2 system tends to fall all by itself?
I believe this earth system without an external interaction should seek ONE equilibrium and one only.
Dont believe all you hear from IPCC. 🙂
This hypothsis is totaly NOT likely and NOT proved in any way!
Chris – According to UAH, global temperature from Jan 1990 to Jun 1991, i.e. the month Pinatubo erupted, averaged +0.12C.
Hmmm, The effects of Pinatubo would not be evident immediately in the global mean so I wonder why you chose a rather unusual 18-month mean, rather than say,the average for 1990? 1990 starts at month 132 here. Ah now it becomes clearer. Naughty.
One does not measure a trend in a noisy signal by examining just the start and end, a least squares fit of all the UAH monthly data points from Jan 1990 gives a trend of 0.17C to 2 dp, right on the IPCC money.
As to the near future, well that is weather rather than climate, however the IPCC projection would give average UAH anomalies for 2010 of around 0.42C, an increase of 0.26C over the most recent monthly figure. A tall order, possibly, until one remembers that in the 2 years leading up to the 1998 El Nino, UAH temperatures trended up at 0.26C a month.
Fun with numbers!
Kim lucia’s Blackboard at rankexploits.com for the truthseekers out there.
Lucia examines the IPCC projections vs observations over a clmatically-significant period here
From the intro .. What’s the best way to convince skeptics warming is real?
Visiting may blogs and forums, I have developed an impression some believe the best way is to snark, scream, and throw tantrums, deny anything could look the slightest bit contrary to any consensus warming claim for even a mili-second.
I think a better way is to show data over time and let people watch how things evolve. I think it’s paticulary important to admit that some claims aren’t currently supported with any great confidence and to show that occasionals outliers arise. In that light, I compare IPCC projections to data, and will continue to do so. The fact is, I’m confident we will see warming. I seriously doubt it will be 2C/century between now and 2030. But who knows? I could be wrong. If so, I’ll be posting regularly, and people will see the temperatures turn.
cheers,
JP.
WUWT seems to have damaged the URL for the Lucia post … here it is
http://rankexploits.com/musings/2008/introducing-my-version-of-slide-and-eyeball/
REPLY: PEBKAC
Indeed. Mea Culpa Maxima.
John Philip.
Are you simply trying to be provocative. I’ll try and reply simply and to the point without a rant.
You are the one who picked the 1990 starting point:
““The IPCC projected that temperatures would rise at an average of around 0.175C / decade from 1990-2010. According to the UAH satellite record the actual rate was 0.174C /decade.”
In order to compare like with like, you have to adjust for ENSO as I did.
I went as far as I could from Jan 1990 before I got to the Pinatubo eruption.
Look at the UAH figures from Jul 1991: 0.20, 0.22, 0.07, -0.04, -0.10 and so on, eventually down to a low of -0.39 in Aug 1992. And what state was ENSO in during that time? El Nino! (Peaking from Oct 91 to Jun 92)
Your reference to El Nino 1998 is irrelevant because it was in the middle of the 16-year period which we’ve already established had a (UAH) trend of 0.106C / decade, adjusted for ENSO and Pinatubo. This would suggest that if we have an equivalent El Nino in say 2010, the 16-year trend from 2004-2020 should be similar. What you need is a Super El Nino+++ to achieve the acceleration in trend you require. And where do you suppose all that triple-hot water is currently hiding?
I can’t believe I even wasted my time replying to this. Sorry, it’s late and I’m in a bad mood. And you seem like the type to play clever games so you’ll probably try and confuse the issue or provoke some more. Fine. What are you trying to prove. Convince people that the properly adjusted trend is nearly twice what it actually is. Fine. Does the truth matter? Maybe it doesn’t if global warming really is soon to triple in speed and people need convincing of it at all costs. Or does the truth always matter…..
Well I did rant in the end.
Actually, just thought, to be fair, maybe you don’t understand ONI (re: your strange “naughty” comment. Go and look it up.
Since Dr. Meier mentions elephants, here’s an elephant we should watch out for:
The mathematical physicist v. Neumann once said to his young collaborators: “If you allow me four free parameters I can build a mathematical model that describes exactly everything that an elephant can do. If you allow me a fifth free parameter, the model I build will forecast that the elephant will fly.”
from “Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame of Physics” by Gerlich and Tscheuschner,
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v3.pdf
O.M.G…. I CANNOT believe this assertion:
“Any natural-causes explanation must be accompanied by an argument for why and how human-caused greenhouse gases (GHGs) are not affecting climate in the same way that natural GHGs affect climate.”
Was he serious? Is he really a scientist? One must disprove everyone else’s theories before promulgating or proving their own?
OK….. by that logic, here’s my tongue-firmly-in-cheek assertion ….
ANY EXPLANATION THAT AGW IS CAUSED BY ANYTHING OTHER THAN WHATEVER CAUSED THE MWP MUST FIRST INCLUDE AN ARGUMENT FOR WHY AND HOW THAT WHATEVER CAUSED THE MWP IS NOT AFFECTTING THE CLIMATE THE WAY THAT IT AFFECTED THE CLIMATE LAST TIME.
O.M.G…. I CANNOT believe this assertion:
“Any natural-causes explanation must be accompanied by an argument for why and how human-caused greenhouse gases (GHGs) are not affecting climate in the same way that natural GHGs affect climate.”
Was he serious? Is he really a scientist? One must disprove everyone else’s theories before promulgating or proving their own?
OK….. by that logic, here’s my tongue-firmly-in-cheek assertion ….
ANY EXPLANATION THAT AGW IS CAUSED BY ANYTHING OTHER THAN WHATEVER CAUSED THE MWP MUST FIRST INCLUDE AN ARGUMENT FOR WHY AND HOW THAT WHATEVER CAUSED THE MWP IS NOT AFFECTTING THE CLIMATE THE WAY THAT IT AFFECTED THE CLIMATE LAST TIME.
John Philip says
“The effects of Pinatubo would not be evident immediately in the global mean…”
I dont agree, check this:
http://www.klimadebat.dk/forum/attachments/elnino34.jpg
Chris, No, I did not pick the 1990 start point – that was the IPCC baseline. The IPCC made several projections, clustered around an increase of around 0.35C by 2010, a linear trend of approx 0.175.C/decade.
Fitting a linear trend to the actual data 1990-now using OLS gives 0.17C .decade. No need to ‘adjust’ for anything. This uses all the available data rather than (carefully) selected groups of points at the start and end of the period and so gives a statistically superior estimate of the actual trend. Sorry, but there it is.
JP.
John Philip (08:07:47) :
What’s that definition?
I see about 0.17 K/decade between 1990 and 2000, much less since 2000.
http://woodfortrees.org/plot/uah/from:1990/plot/uah/from:2000/trend/plot/uah/from:1990/to:2000/trend
John Philip (16:09:46) Particularly note “I think it’s particularly important to admit that some claims aren’t currently supported with any great confidence”
And I agree with lucia, time and data will tell. What are they telling us now?
========================================
I concur with many of the above posters. Dr. Meier, your explanations are very well put, and you have good points, but your primary premise is faulty because it is based on the post-hoc and the negative proof logical falacies.
The problem is that there is no evidence that CO2 is responsible for the warming. Previous warming anomalies show that natural variability exists on the same scale as current warming, so we cannot eliminate natural causes as the source of current warming. More importantly, the southern hemisphere has shown no warming at all. As greenhouse gas warming is a global phenomenon that should be more-or-less even planetwide, this is a very large piece of evidence that the warming is not caused by greenhouse gases.
Finally, the fact that we cannot prove that it is natural does not mean that it is man made. As a scientist you must know that in a situation without conclusive evidence, no conclusion can be drawn. Whether the uncertainty merits action on climate change legislation is a matter of debate, but do not foist a negative proof on us as evidence.
I noticed that several people have cautioned that the “Csomic Ray influence, on cloud formation ; has not been proven; has only worked in the laboratory; etc etc.
Well “global warming” by CO2 has NEVER been proven, in fact all the long historic “data” says that global warming causes atmosperic CO2 to change and not the reverse.
The cosmic ray/charged particle “effect” is a lot more compolicated than just being the sole cause of cloud formation.
A result of the solar magnetic flux changes, that accompany sun spot cycles is more than just the global flux of such particles.
The magnetic fields that accompany sun spots reverse every 11 1/2 years,sp the magnetic cycle is 23 years. So far as I know, the earth magnetic field does not reverse in synchronism with the sunspots, so in one sunspot cycle the vector sum of the solar magnetic field, and the earth magnetic field, is quite different, and a 23 year climat/sunspor linkage has been observed, but not an 11 year effect.
In addition to just the total cosmic rays striking the earth, a significant effect of the local magnetic field, is that cosmic ray and solar charged particles are steered selectively by the fields. Particularly the lower energy charged particles lock onto the local magnetic field and spiral around the field lines to end up striking the atmopshere, in the regions of the magnetic poles; which is well known as the origin of aurorae in the polar regions. So what ?!.
Well as everybody knows, the polar regions are cold, and the tropical regions are hot, so water vapor in the atmopshere tends to be concentrated in the warmer regions, and scarce in the polar regions. So anything that steers charged particles around alters the cloud formation, because in the tropics, there’s much more water to nucleate. Cosmic rays concentrating near the poles have little water vapor to work with, and lower relative humidities too.
Don’t look for a bold effect that stands out like a sore thumb like the Mauna Loa annual CO2 6 ppm amplitude cycle.
Global cloud cover has only been observable since the first polar orbit satellites went up circa 1979, so albedo effects of clouds, and the growth and loss of polar ice sheets, it a relatively young quantitative study. And I can’t imaging how ground based global cloud studies can even be conducted.
But Wentz et al showed that a one degree C rise in global surface mean temperature (whatever that is) causes about a 7% rise in global evaporation, and a 7% rise in total atmospheric water vapor; and also a 7% rise in global precipitation. Of course precipitation tends to happen somewhere else from where the evaporation happens, and at some other time, but they have to equalize; and precipitation means DARK clouds, that can’t really be studies quantitatively from satellites, although albedo effects can.
So I take statements that there is no link between cloud cover and global temperatures with a grain of salt.
No, I am not a researcher in this field, and I have to take the reported data that others gather, and try to find some sense in it. You might have noticed I try to find some way of explaining it in temrs that any 8th grade high school science student can grasp. Doesn’t matter if scientists can understand it; if the public, and the politicians can’t understand it, then they will believe any story the AGWers give them. I don’t have any axes to grind; I don’t and never have worked for any energy/resource development company, nor do I invest directly in their stocks or their products. So I buy gasoline, and maybe my 401K fund, invests in energy behind my back.
Neither do I swill at the public trough and constantly beat up on the tax payers to keep funding my research. Have you noticed the government generally doesn’t fund studies to show ansolutely nothing untoward is happening; so researchers know that is not a fruitful line of research. I have a friend lawyer, whose specialty is defending doctors against medical mal practice suits; and he makes good money at it. His clients are well heeled insurance companies who can afford his fees; and his experience is that a very large fraction of malpractice suits are simply fraudulent; which is not to say malpractice doesn’t occur. He doesn’t take those cases.
Bank robbers rob banks, because that is where the money is.
So all I care about is that we get the science correct, and we do so, before we actually destroy this planet, both ecologically, and economically.
No cosmic rays/solar particles are not the be all and end all of climate; but they do amplify the effect of solar activity, as it manifests in sunspot cycles; and anything including dust, that enhances cloud nucleation leads to cooling, and anything that inhibits cloud formation leads to warming.
I leave it to those wh do do field research in these areas to put some meat on the bones.
But frankly, as a physicist and mathematician, I would not want to have to try to defend the AGW climate thesisi.
When I went to school, any thesis that claimed the cause (CO2) of some effect (global warming), actuaally happend as much as 800 years after the effect has happened, would be a statutory bar to that theory. Today in this internet blog world it is just a ho hum. Yes I do understand the infra-red spectroscopy mechanism of molecular absorption as in the CO2 molecule; and I understand how that can result in heating of the very surface of the planet; which is 73% water; and at that point the water cycle takes over. The exact quantitative aspects of that relationship, I will leave to thiose in the field; but the mechanismis unavoidable.
I’m also an analog circuit designer of long standing, so I understand exactly how feedback works; and it is physically impossible for the input signal (cause), to happen after the output signal (effect); if for no other reason, that energy processing systems must have a propagation delay.
The claimed CO2/ water feedback system is in my view just nonsense; bcause feedback systems, actually have a time response as well, and the delays in climate systems are such, that these feedback systems would oscillate wildly, if these feedback were really there. Feedback amplifiers tend to go into limit cycle rail to rail oscillations, if the delays are excessive for the amount of feedback; and you don’t see too many climate systems that are in oscillation. The Mauna Loa CO2 signal is not an oscillation, but a clear result of the driving input signal that is linked to the rotation of the earth, and its orbit around the sun.
I’ve seen a lot of “climate papers” that talk about “forcings” and “feedbacks”, but I’m still waiting for such an analytical paper that includes the time response of that system.
Well the trouble with computer “GCMs”, is that they may be climate models; but they certainly aren’t models of the climate of any planet in our neighborhood. The idea that a mean global temperature exists all over the world, instead of a daily temperature spread that can be as much as 150 deg C, and that the earth radiates at a constant 390 Watts per square meter, from pole to pole 24/7, per the official NOAA energy budget diagram is just silly.
Averaging the measured temperatures at various points on earth at various times, makes almost as much sense as averaging all the telephone numbers in the Manhattan phone book, and claiming that is the mean NYC telephone number. those temperatures are all differnt, because they are supposed to be; and their average has no scientific meaning or validity whatsoever.
Dr James Hansen’s GISStemp anomaly plot, is a graph of the GISStemp anomaly; and nothing else. Every point plotted on that graph, was measured nowhere at any point in time, by anybody; it is simply the manufactured output of applying some unknown algorithm, to some unknown and closely guarded secret set of raw data; whose long term history integrity is highly suspect.
Likewise HADcrut, and RSS, and UAH, are simply plots of other algorithmic outputs from other raw data sets done by other people. All of them are interesting relative to other data points on the same page; but they don’t agree with each other, which is all the proof that you need, that none of them is likely to be an accurate measure of anything like a mean global surface temperature. they don’t have any meaning at all other than on that page they are plotted on.
We don’t have any sound practical method to measure a real global mean surface temperature; and in the unlikely event we came up with a method; the result would still be meaningless, because energy gains and losses from the earth have no simple relationship to any such number. Just the radiative losses from the earth are more related to the fourth power of temperature; so even the mean 4th power of temperature would be more meaningful; but still useless because each differnt terrain type, has totally different thermal processes.
The John Q Citizen public takes GISStemp as the gospel truth mean global surface temperature, even though it is labelled an anomaly, which presumably means it is always wrong if it isn’t zero. They can’t even give it a real temperature scale value, because it is referred to some other mean number over some period of time, during which they were also unable to measure the mean temperature of the earth.
That is not my idea of science, when we discard the Newtonian theory of gravity, in favor of Einstein, all because we found that the precession of the perihelion of Mercury was off by 43 lousy seconds of arc per century, from what Newton said it should be. We don’t abide physical theories that have glaring discrepancies between theoretical (modelled) predictions, and actual experimentally observed data.
I’m still having trouble understanding these positions:
“…I do not understand Dr Meier’s starting position to be anything other than a recognition of that (entirely rational) proposition. So, when he asserts that it is for those arguing against AGW to prove their case he is saying: “Look chaps, we know we are putting more of the heat-making stuff up there so you tell me why our extra heat-making stuff isn’t making extra heat.”..”
As I said earlier, we don’t know how strong the ‘heat-making’ (sic) stuff is. A major plank of the warmers argument is that it’s strong – the deniers say it’s weak. With that as the point at issue, you can’t just assume it’s strong and then say to your opponent “Where’s the extra heat? “. The deniers argument is that there ISN’t any….
“It may be that AGW is so small as to be insignificant, but that is a world away from saying it does not exist at all.”
Ummm. In theory you are right. Something that is insignificant still theoretically exists. But in terms of the AGW argument something that provides an insignificant rise in temperature, which is too small to be measured, does NOT exist in any practical sense, and it is a reasonable comment to say this. Otherwise we will have to keep on referring to the extra global warming we cause on the soles of out feet when we walk across the room…
“…the predicted temperature rise due to that forcing, summarised in IPCC AR4 WG1 Section 9.6 which give an expected increase in temperature, after a doubling of CO2e, in the range 2-4.5C. As this is consistent with recent observations, his point is that the onus is on those who propose a purely natural and alternative explanation to provide a mechanism (solar, ocean circulation changes, or Factor X) that would explain the warming, and explain why the radiative forcing of the increased GHGs is not having the predicted effect…”
Again, the hidden assumption here is that because I can correlate CO2 increase with temperature in a model, the one must be causing the other. The correlation falls down in recent years, so most appropriate thing to say is that it must not have been an accurate assumption to start with. Instead, this strange position takes the 20 years of correlation as proof that this is a causual relationship, and then tries to defend the relationship when it fails by saying that since some heat is missing, your opponents must find it before they can continue the discussion.
It’s NOT there! And the fact that it’s not there is the fact that breaks the concept of AGW.
George E. Smith (12:19:31) :
The magnetic fields that accompany sun spots reverse every 11 1/2 years,so the magnetic cycle is 23 years. So far as I know, the earth magnetic field does not reverse in synchronism with the sunspots, so in one sunspot cycle the vector sum of the solar magnetic field, and the earth magnetic field, is quite different, and a 23 year climate/sunspot linkage has been observed, but not an 11 year effect.
Except that is not the way it works. The solar magnetic field is drawn out in interplanetary space by the solar wind, but the field there [the IMF – interplanetary magnetic field] changes polarity [into the Sun or away from the Sun] every 7 days on average. The north-south part of the IMF changes every few hours. None of these changes have anything to to with any climate/sunspot linkage on the the timescale of decades or years.
Global cloud cover has only been observable since the first polar orbit satellites went up circa 1979, so albedo effects of clouds, and the growth and loss of polar ice sheets, it a relatively young quantitative study
Cosmic rays and solar wind particles to first other do not change on a 23-year cycle, but on an 11-year cycle. The cloud cover http://www.leif.org/research/cloud-cover.png and albedo http://www.leif.org/research/albedo.png do not show any 11-year period.
And I can’t imaging how ground based global cloud studies can even be conducted.
Well, other people can. The cloud cover and the resulting albedo are closely related. There are observational programs running right now that measure the Earth’s albedo by measuring how bright the Earthshine on the Moon is.
So I take statements that there is no link between cloud cover and global temperatures with a grain of salt.
And to accept that there is a link requires not just a grain but a whole bag of salt.
cosmic rays/solar particles are not the be all and end all of climate; […]I leave it to those wh do do field research in these areas to put some meat on the bones.
So far, the bones have been hard to come by.
I do share your frustration, but one does not combat bad science with worse science.
I see about 0.17 K/decade between 1990 and 2000, much less since 2000.
Ric – use all the available UAH data and one discovers that the obsevations after 2000 are actually mostly above the long term trend line, which is not fantastic evidence for a levelling off, never mind cooling …
http://woodfortrees.org/plot/uah/from:1978/to:2008/plot/uah/from:1978/trend:2008
@Ron:
O.M.G…. I CANNOT believe this assertion:
“Any natural-causes explanation must be accompanied by an argument for why and how human-caused greenhouse gases (GHGs) are not affecting climate in the same way that natural GHGs affect climate.”
Was he serious? Is he really a scientist? One must disprove everyone else’s theories before promulgating or proving their own?
I think you did not understand Dr. Meier. He did not mean that you must disprove his hypothesis to to prove your own.
He ment that in order to prove your own hypothesis about climate change, you must take ALL known and relevant physics into consideration. The IR absorption of CO2 is relevant to any hypothesis concerning climate change. This is even more true if this hypothesis sets out to disprove the rising CO2 level as the cause of climate change! Physics do not take sides.
@george E. Smith,
Your posts are very long and hard for me to follow, so I will not react to everything in them. But this has me puzzled:
I’m also an analog circuit designer of long standing, so I understand exactly how feedback works; and it is physically impossible for the input signal (cause), to happen after the output signal (effect); if for no other reason, that energy processing systems must have a propagation delay.
I think you forget that there is a third element involved: orbital changes. This triggers the increase of temperature, which increases the amount of CO2, causing the temperature to rise more. In the context of this mechanism CO2 is a feedback.
Leif (15:45:33) on 20/10. Do you have any idea what causes the shape of solar cosmic rays around maximum to alternate solar cycles from peaked to rounded? Also, have Bill Livingston’s measurements of the magnetism of the last few spots fallen within the range of the decline curve to 2015?
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I think I’ve never heard so loud
The quiet message in a cloud.
Still louder, now, but still and all
Still ’tis shadows on a wall.
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I am looking at the FAQ 2.1 Figure 2 from IPCC Working Group I Fourth Assessment Report, 2007 that Dr. Meier referenced for Radiative Forcing of Climate between 1750 and 2005. Am I reading this graph correctly? — we would still be in the Little Ice Age if not for the anthropogenic contributions to warm up the planet starting in 1750! Natural variations are insignificant in relationship to what humans have done, so when glaciers started to retreat in the 18th century, that was due to human burning of fossil fuels. There might have been variations in climate before 1750 (as evidenced by what retreating glaciers uncover), but since 1750, it has been humans that have caused climate change. On another blog, a pro-AGWer confirmed the intepretation of the graph that humans have driven climate for the past 260 years.
A question for Dr. Meier:
In pre -000 pictures of Arctic ice cover, snow is not part of the picture and we see ice area extending into fjords, etc. In the pictures of the the last few years, we do not see this ice cover, rather the area shows up as snow. Did previous years’ ice area (and extent) get credited with ice-covered fjords while current year’s ice are (and extent) not get credited? Or has this issue been taken care of?