Anthropogenic Global Warming, or just Natural Variation?

A climate tutorial
denis ables )

The atmospheric level of carbon dioxide (CO2) began increasing in about the mid 1800s, about the time our industrial revolution began.  Our current global warming had already been underway for 200 years, beginning in the late 1600s, as the little ice age bottomed out.

Is the increasing level of CO2 driving our temperature, and even if not, won’t the steady (although slowly) increasing CO2 at some point bring on other problems?  The question is clearly NOT: Has there been “climate change“?  Climate change has been ongoing for the past 4 billion years.  Neither is it:  “Has there been “global climate disruption“?  There’s clearly been a lot of that in the distant past too, unless you choose to ignore such things as our periodic ice ages.  Also, there are NO climate change deniers.  The term climate change, and climate disruption are political constructs. The basic issue is whether the industrial contribution of carbon dioxide to the atmosphere is impacting our temperature, and if so, how much?  Some other climate issues, such as ocean warming/cooling, hurricanes or tornadoes only arise as a result of temperature changes, so are moot unless/until it is proven that man has significantly impacted the planet’s temperature.

There’s hardly any any doubt that man may have some influence on the planet’s temperature. Our metropolitan areas are known to be significantly warmer (the Urban Heat Island effect) than the surrounding rural areas, for example.  Other changes in land use may also have an impact. That we may be having some impact on climate is not in question;  the relevant issue is how much of an impact is man having, and, is it sufficiently significant to introduce problems?  A secondary but serious  question involves the tradeoff in cost to address such an issue, if it does exist.

Al Gore refers to a “simple” physics experiment which demonstrates that adding CO2 to a heated enclosure tends to increase the temperature therein. However, in the open atmosphere there are other  feedbacks to any temperature change, and it is not yet been proven whether these feedbacks are, in aggregate, positive (amplifying the warming) or negative (reducing or eliminating the warming).  Water Vapor, in particular, is also a “greenhouse gas”, and is, on average, 50 times more prevalent in the atmosphere than is carbon dioxide.  The computer models used by warming proponents assume that the water vapor feedback is not only positive but sufficiently so that it amplifies the CO2 warming influence by a factor of 2 or 3.

My educational background was math (major) and physics (minor) (B.S. Tulane (1960)) and subsequent graduate level math, mostly at The Courant Institute of Mathematical Science (NYU).  Neither my education nor work experience included any climate science. I am retired, have no ties to “big oil” or any other such entities.  The information provided herein has all been established by numerous credible sources, and references to those sources are included.

The interspersed website references in this document can be bypassed, at least during a first reading, without losing the thread.  But I encourage you to return to those when you have time.

There are many so-called “skeptic” websites and books available, and there are numerous credible skeptic voices out there, and include many well educated and experienced in climate science, and related disciplines (geology, physics, oceanography, astrophysics, among others). These folks cannot simply be written off as “flat-earthers” or “climate change deniers”.  The level and sophistication of the “chatter” by skeptics of catastrophic anthropogenic global warming (CAGW)  on the internet far surpasses what one might expect, given the very limited coverage by the major news media.

It is clear that for over 4 billion years our planet’s warming and cooling, as well as other climate variations, were invariably due to what can be called “natural variation”.  Humans could not have had any signficant impact until recently, so that must remain the null hypothesis unless/until those who claim otherwise can provide sufficient evidence to prove their case.  (For example, whether cloud feedback is positive or negative remains debatable.)

So, what’s different about our current warming than the other earlier warm periods during this interglacial, the most recent being the Medieval Warming Period (MWP) about 1000 years ago?  The MWP has been well established as a global (not just regional) event and man could have had no significant impact on temperature back then.    

Immediately below this paragraph are two other websites, each offering a different style of introductory presentation for the climate issue; the first is partly video and audio, the second is completely video, consisting of eight “youtube’ recordings, a presentation by Lord Monckton to university students.

A brief summary on the climate issue by a Princeton physicist (Happer) follows:

Joanne Nova’s website (referenced below) offers a “Skeptics’ Handbook” which is very worthwhile. Evidently more than a hundred thousand copies have been downloaded.  The following comment by Joanne, to one of the global warming proponents follows:

“The only rational response to climate change is to use empirical, observable evidence. Rational people can point to results from 28 million radiosondes, 6000 boreholes, 30 years of satellites, 3000 ARGO ocean diving thermometers, raw data from thousands of surface thermometers, as well 900+ peer reviewed references on the MWP (links to all are provided at which include studies of corals, caves, pollen grains, ocean floor sediments, ice cores, and diatoms.”

Many scientists have taken exception to the claims of anthropogenic global warming, and as you will see, declarations by the AGW proponents that the science is “settled” are wrong.  In fact, science issues are rarely, if ever, “settled” and claims to the contrary should be viewed with suspicion.  Neither is “the” science determined by which side has the most votes; it’s usually one or two scientists who move the discipline forward, invariably to the dismay of the majority. Scientists, by the very nature of their discipline,  must forever remain skeptics, even of their own theories.  However, in the case of (CAGW) claims, politics has clearly overwhelmed the science.

For the past 1.3 million years there have been 13 ice ages, average duration 90,000 years, each followed by an interglacial period, average duration 10,000 years.  More on the longer term climate history, including a 65 million year overview of climate and related information, is available at the websites below.  (Keep in mind that the planet has been around for more than four billion years.)

Note that, while both of the websites above show plenty of temperature variation, there appears to have been an overall cooling trend over the past 65 million years.

If our recent 13 cycles of ice ages, each followed by a much briefer warming period, continue then we are (unfortunately) nearing the end of our current interglacial period.  Of course, whether the trend over the past million years continues remains to be seen. There were different variations earlier and there are no doubt some future surprises ahead. The important point is to gain some appreciation for how much history must be taken into consideration to gain a proper perspective on “climate change”.

During this current interglacial there have been several periods when temperatures were warmer than now.  Our most recent prior warming, and hence best documented, was about 1,000 years ago, from around 800 to 1200 AD, and is known as the Medieval Warming Period (MWP).  As obvious from the graph below there were also several earlier periods which were even warmer.

Time (before present) increases from left to right in this chart. ) 


There is also anecdotal evidence supporting the MWP.  Ancient vineyards dating to the MWP have been found in northern areas in Scotland (and elsewhere) where even today it is not warm enough to grow grapes. The Vikings took up residence during the MWP on “Greenland” (and named it).  They were also evidently able to map the entire coast line of Greenland which is a strong indication that it must have then been free of ice.  Burial graves have also been found below the perma frost which also makes it likely that the MWP was warmer than now.

Our most recent cooling period ( from about 1200 to 1600 AD)  immediately followed the MWP,  and is referred to as “the little ice age”.  The earlier reports by the UN’s International Panel on Climate Change acknowledged both the warming and the subsequent cooling period.  The cooling period started about the time that the Vikings began leaving Greenland.  As can be seen from the references and graph above, some 900+ scientists from approximately 400 institutions and representing some 40+ different countries have concluded that(1) the MWP was as warm or warmer than now, and was global rather than just a regional phenomenon, and (2) there were several earlier durations during this interglacial which were even warmer. In fact, new investigations using different and/or better techniques continue to show up quite regularly and continue to confirm the existing studies.

The major players, both proponents of CAGW, were the two Climate Research Units (CRUs) supporting the UN’s Intergovernmental Panel on Climate Change (IPCC).  In recent reports the CRUs dismissed the hundreds of independent peer-reviewed MWP studies, declaring instead that the MWP and little ice age were merely regional phenomena. The dismissal of all these studies was centered on one CRU study, by Michael Mann, which has subsequently been debunked by several sources. Also, the “purloined” emails, referred to as the “ClimateGate” scandal, much of which should have long ago been released under freedom of information requests, show specific reference by CRU folks wanting to “get rid of the MWP”.  (? Why ?)

Mann’s claim resulted in a very different characterization of climate over the past 1,000 years.  His  new graphical representation, popularly referred to as the “hockey stick graph”, essentially minimized the impact of both the MWP and the subsequent little ice age.  Basically, the entire temperature increase in the hockey stick graph shows most temperature increasing taking place in more recent times.  As you might expect, dismissing the work of so many other researchers would have been unbelievably controversial even if Mann’s claim had some validity.  (The Marx Brothers’ line comes to mind: “are you gonna believe your own eyes or me?”)  The Hockey Stick Graph has been roundly rejected by several peer reviewed papers. Recognition of a couple of the early players who took on the CRUs must be acknowledged.  The two “outsiders”, Steve McIntyre and Ross McKitrick, demanding to see the data and to examine the processes were held at bay for years. They demonstrated that Mann’s computer model, which was used to generate the hockey stick graph would, when provided with randomly selected data, always generate a hockey stick graph.  In a normal world that should have been more than sufficient, (not to mention the MWP studies) but these AGW folks have managed, with the help of strong mainstream media support, to pull more than one stake out of their heart.

So, if temperature levels, on several occasions during our current interglacial period, have been  sustained at relatively high levels for hundreds of years, when man could have had no impact, why this concern about the current warming?  

For the past  600,000+ years there has been a very strong correlation between the variations in the atmospheric level of carbon dioxide (CO2) and the very similar temperature fluctuationsIt was perhaps not unreasonable to assume that CO2 was driving temperature, because the level of CO2 was known to be increasing as a result of our growing industrial activity. That, and the fact that some physics experiments indicate that increasing CO2 will cause an increase in temperature, at least in a controlled environment.

However, subsequent investigations, including examination of more recent core samples, where both CO2 and temperature data were taken using more accurate techniques, and/or from the same rather than from separate samples, showed that there was actually a long lag (800 to 2500 years) between temperature variation and the  later very similar fluctuations in the CO2 level.  It was temperature that increased first!  CO2, at least in the more distant past, was clearly not driving temperature. The ocean, a huge repository for carbon, containing more than 50 times that of the atmosphere and an integral part of the carbon cycle was, after an 800 to 2500 year delay, releasing CO2 back into the atmosphere, and was performing this action in such a way as to make nearly identical oscillations in CO2 volume as was performed earlier by changes in temperature ! (Unlike the atmosphere, temperature changes in the much denser ocean occur very slowly.  Gas is released when the ocean is warmer, and absorbed when it is cooler.) Nothing unusual here – this is the well known carbon cycle.
During the past two centuries it happens that both CO2 and the global temperature were increasing. (Keep in mind however that temperature had begun increasing some 200 years earlier.) Since this new shorter term relationship coincided with the beginnings of our industrial revolution the earlier notion – that increasing CO2 was having a significant impact on temperature – was resurrected. But (once again) from about 1942 to 1975, a 30+ year period, while the level of CO2 continued to increase, the planet was cooling.  In fact, during the 70s more than a few scientists, some of the same folks now alarmed about warming, were then predicting the onset of the next ice age. Obama’s science adviser, Holdren, was a member in good standing in that fraternity.

Also noteworthy – most of the warming during the past 150 years took place during two specific periods (1910 – 1940, and 1975 – 1998).  The earlier warming period between 1910 -1940 was associated with a 14% increase in CO2 emissions, whereas  during the cooling period of 1942-1975 there was a 500% increase in CO2 emissions.  This presented a serious problem for the proponents of CAGW.  However, the CRUs evidently ascribed the lack of temperature increase during the 1940-1975 period to other unanticipated (and presumably unusual and/or periodic – but “natural”) influences and chose to ignore that anomaly.


The computer models used to predict warming temperatures evidently all continued to reflect the belief that CO2 was the temperature driver.  But, then, beginning about 1998, temperature once again basically leveled off while CO2 continued to steadily increase.   Satellite measurements (rarely mentioned by the mainstream media or the “warmists”) show cooling for the past decade. The computer models projecting CAGW also predict that, if greenhouse gas is driving the temperature, then the upper troposphere above the tropics should be warming considerably faster than the surface.  (The troposphere is the lowest layer of Earth’s atmosphere. We live in the troposphere.) There has been no sign of troposphere warming.  Joanne Nova, on her website, includes an extensive discussion on the absence of warming in the upper troposphere. The proponents of CAGW continue their so far unsuccessful search for that warming.

There is the added issue that, if the Arctic Ocean begins losing its ice cover, the additional open ocean will begin absorbing more carbon dioxide.  That would presumably provide a negative feedback! (In fact, ice coverage has evidently been increasing since its low in 2007.)Satellite measurements are now indicating that, when the planet is warmer, there is more heat escaping to space .. yet another blow to the CAGW claims.

It has became clear that the computer models (the output of which has often been erroneously referred to as “evidence”) have not accurately  projected even our current climate, let alone the climate in the next century.  Note that there is a subtle distinction between “predicting” and “projecting”, the latter promising no guarantees, no levels of probable accuracy at all, but you wouldn’t know that from reports provided by the major news media.  The authors of the computer models did apparently describe their results as projections rather than predictions.

Computer models rarely graduate from the testing stage until they have been sufficiently reworked (“tweaked”) to match historical data.  Therefore any claim that such models are reliable predictors because they perfectly reflect past history is bogus.  Historical data is invariably used to build and test computer models. It is the only information available so can hardly be ignored.   Not only that, attempting to predict results 100 years into the future by simulating both a very complex and poorly understood climate (which likely contains chaotic elements) and at the same time making those climate projections dependent on the results of a separate simulation which attempts to project changing world economics (because that impacts CO2 generation) would seem to be a guaranteed exercise in futility.

Last, but clearly not least, one must understand that chaos is likely an integral part of climate change.   Even if climate models were perfect, (a non-attainable objective) the fact that computers must perform calculations with a finite number of digits would quickly render estimates of distant future outcomes grossly inaccurate.  The nature of a chaotic influence is that very small perturbations in the initial conditions can result, in the long run, in a very different future scenarios .  Computer model results, where chaotic elements have to be dealt with, will, when attempting to project results far into the future, quickly degenerate because of propagation of errors due to guaranteed inaccuracy in the initial values. Not only that, it is quite likely that climate may include numerous separate chaotic influences, some of which will probably never even be identified, let alone accurately estimated.

Current temperature data is obtained from either surface stations, satellites or weather balloons.  Earth-orbiting satellite results from the two widely used global temperature data sources, UAH (University of Alabama at Huntsville) and RSS (Remote Sensing Systems) are shown in the two following graphs.  Both show decreasing temperatures over the decade ending in 2008, with present temperatures barely above the 30 year average.

UAH monthly temperature anomalies

Anomalies 1998-2008; University of Alabama (UAH)

RSS Monthly Global Temperature anomalies

Anomalies 1998-2008; Remote Sensing Systems

Surface temperature data, when aggregated, is not always in agreement with satellite temperature data, even before the necessary and questionable machinations are applied to the surface data.  (Professor Robert Carter – a brief video)

Anthony Watts’ website “WattsUpWithThat” (WUWT) goes into considerable detail on the problems involved in using surface temperature data for analysis at the planetary level.  The WUWT participants include numerous volunteers who have actually visited and photographed many of the temperature recording stations. Almost 90 percent of those stations violate the basic government requirements. But, regardless, the raw temperature data must also be revised to be useful, (a process known as “homogenizing”) and the devil is most definitely in the details.  A temperature thermometer 5 feet off the ground will not agree with a simultaneous reading from another only 1 foot off the ground. (Even Hansen of NASA admits this.) Temperature stations in the shade can provide very different information than stations in the sun.  Urban temperatures are several degrees higher than what is experienced in surrounding rural areas.  Temperature readings across the planet must be synchronized to the same times if one is to calculate a global temperature, but some surface thermometers only register the high and low for the day… are you getting the picture?

The only other obvious link between human activity and temperature is the urban heat island (UHI) effect.  UHI appears to be a local phenomenon, because urban area temperatures exceed those in the surrounding rural areas by several degrees (more concrete, buildings, less trees, etc.).  But urban areas constitute a very small percentage of the earth’s total surface area (oceans alone cover 71% of the surface, and then there’s the north and south poles, jungles, deserts, mountain ranges…). In fact, the UHI effect appears to have no impact on the planet’s temperature, because even in the surrounding country-side its effect doesn’t show up, so it should have basically no impact on global temperature.

UHI does complicate the effort to obtain accurate surface temperature data because many of the surface temperature stations are located in urban areas and the UHI effect not only varies with population size but is also influenced by the local station environment (nearby paved roads, nearby a/c exhaust, shade due to nearby buildings or trees, etc.). And we are not talking about variances of a fraction of a degree.  UHI temperatures can be as much as 5 or more degrees above that of surrounding areas. The best strategy would have been to locate all temperature stations in rural areas, but even these stations will frequently be influenced by their local environment and, naturally, subsequent urban encroachment.  Attempting to correct raw data to remove these influences is more art than science, and there are serious questions about the validity of the process used to eliminate the UHI effect from temperature readings, which is a necessary part of the “homogenization” process.  It does not help the “warmist” cause that there is no documentation available justifying exactly what revisions were made.

Temperatures can vary at one locale by 30+ degrees during the course of a single day.  Over an entire year the span at that location between high and low temperature is likely to be be much higher.  Yet estimates of change in temperature trend by computer models involvesperiods as long as a century and  result in changes of a few tenths of one degree – for the planet.  Even such results derived from “perfect” raw surface temp readings, and assuming competent analysis and no human bias, will likely be overwhelmed by the magnitude of the errors implicit in dealing with the raw surface temperature data.

The raw surface temp data is in question for various reasons. Readings at high altitudes will be much cooler than those at lower altitudes.  In many cases where raw data is available over some longer duration, the raw data frequently shows no increase in temperature except in urban areas where the increase could all be attributed to a growing urban heat island effect. (UHI).  Raw data, as well as documents describing the exact machinations performed on it are apparently no longer available.  Of course, the fact that back when raw data was available, the CRU folks refused to release it to outside reviewers only added to the skeptic’s suspicions. (That action alone points to an extremely serious credibility issue.)

From the information presented so far it’s evident that the warming over the past two centuries appears to clearly be within the bounds of natural variation. That must remain the “null hypothesis”. (Believe it or not, one CRU player, in recent speeches, has been urging that the “null hypothesis” be revised instead to his theory. Ex-warmists are considered heretics, so the group does provide a certain religious-like coherence.)   Any hypothesis attempting to replace the null hypothesis must be accompanied by evidence, and because the government policies needed to avert the supposed man-made warming would be unbelievably costly, and probably not successful anyway, the evidence must be strong. 

Neither should the past several hundred years of warming come as a surprise, since this warming period immediately follows a 400 year stretch of cooling known as “the little ice age”. This cycling from cooler to warmer and back is typical. There has been no discernible link established between indicating that CO2 has ever influenced the earth’s temperature, either historically or in recent times.   In a rational world it seems obvious that the data indicate there must be negative feedbacks operating which offset possible temperature increases which might otherwise be caused by increases in CO2. An excellent discussion of the process (scientific method) for confirming or rejecting the CAGW theory appears on the website below:

Be on the lookout for bogus efforts to deny the fact that over our most recent couple of decades there has been basically no warming.  (In fact, if the planet were still warming it wouldn’t matter in any event because there is still no evidence that man is responsible.)   An amazing example of what is declared to be “evidence” of CAGW – that the earth has continued to warm right up to today, and “there is no other explanation”,   is provided below (and aptly named) by Joanne at her website.  Evidently at least one confused professor, who nonetheless made himself available to publicly pontificate on climate issues, cannot grasp the concept that (1) several recent years can currently be considered the “hottest” on record since the 1800s and (2) during this same period the earth’s temperature has not been rising, even cooling a bit.  (It’s been warming since the mid 1600s, so the most recent decade will  – by definition – contain most of the warmest years.  Very small increases in temperature in any recent year will be sufficient to make that year “hottest”, and very small decreases may not be sufficient to remove a recent year from being among “”  ten of the hottest”. )

NASA’s Hansen has been quick to claim that 2010 is the hottest year yet.  What he did said more quietly is that the measurement is meaningless, because the differences between 2010, 2005, 1998, and some other earlier years in the 1930s is a minute fraction of one degree C.  That minute difference is NOISE. But, even assuming that 2010 is the warmest, so what?  We may have another century, or more, of natural warming and may still not even rival MWP or earlier warmings during this interglacial.

There are some serious questions about NASA’s GISS data. In its temperature weightings, it seems that the collection process assumes the northern hemisphere is 70% land when it is actually closer to 40% !  Also, in the recent past, data stopped being collected from most of the 6,000 available temperature stations, and most of the eliminated stations appear to have been in higher latitudes or at higher altitudes (both cooler areas). There is apparently no documentation justifying either the radical reduction in surface temperature stations or in the filtering process.

Dr. Fred Singer, and Dr. Roy Spencer,  together with many other scientists, believe that satellites and high altitude balloons are the only feasible way to estimate the planet’s temperature.

But, what about carbon dioxide?  It’s pretty clear we are contributing to that, and it’s now well above (what appears to be) a relatively long established ceiling of 280ppmv (parts per million by volume).

In the more distant past (around 100 million years ago and beyond, and keeping in mind that the earth is 4 billion years oldcarbon dioxide levels were generally much higher.  We know that higher levels of CO2 are great for plant life, and there is no evidence that these higherlevels had any harmful effect on animal life. The CO2 level has also been much higher during at least three ice ages, and  CO2 was much higher going into one ice age, so, once again, it does not appear to have much influence on temperature, even at these higher concentration levels.  

The “greenhouse effect” (the capacity for CO2 to absorb outgoing infrared energy and re-radiate some of it back to the earth) is limited to just a few wavelengths (5 and 15 micron range) in the case of CO2. (“Absorb” is in this context questionable since the energy flow is only interrupted for a fracture of a millisecond.) There is a limited amount of this range of energy so, as a consequence, CO2 energy absorption falls off very quickly as the level of CO2 in the atmosphere increases.  At 20 parts per million by volume (ppmv), 50% of atmospheric CO2 absorption capacity is already used up, so at our current atmospheric level (390ppmv),  the absorption capacity has, for all practical purposes, been exhausted.  But wait …!  An internal IPCC study (the “carbon isotope argument”) claimed that airborne CO2 molecules emitted by man (burning coal, for example) had a human signature and so were distinct from naturally created CO2, and, (you may be able to guess what’s next) it is “human-caused CO2” which is the culprit.  That low key study has finally been reviewed by outsiders, the authors of a new book ‘Slaying the Sky Dragon: Death of the Greenhouse Theory’ and found lacking (to put it politely). One would expect such an “important” discovery to result in considerably more public exposure, (and hence a more thorough investigation). Since this had to do with an isotope of CO2 the term “isotape-gate” has already been attached. 

A new related peer-reviewed study shows that UV radiance has increased by 50% since the 1600s, which would seem to account for most of the IPCC’s estimate of warming over the past century.  UV radiation can penetrate ocean surface whereas long-wave radiation (generated by feedback from greenhouse gas) cannot. (If that feedback energy is instead reflected it will evidently have little effect.  See website immediately below:

Carbon dioxide currently represents just under 4/100 of one percent of the atmosphere, approximately 390 ppmv of the atmosphere. (Human breath contains about 4%, or 100 times as much.)  The level of water vapor, also a greenhouse gas, (but ignored in favor of CO2 by the Environmental Protection Agency) varies, but generally makes up  1% to 4% of the atmosphere, so is approximately 50 times more prevalent than CO2.  In recent years the annual increase in CO2 has been linear, about 2ppmv. While methane, as a greenhouse gas is 20 times as potent as CO2, it is much more of a trace gas, taking up only 1/200 of the volume occupied by the trace gas CO2.

While it’s definitely worth studying this issue, one should remember that the evidence from actual data, both historical and in more recent times, indicate that CO2 – even at much higher atmospheric levels, has not been a significant driver of temperature.  (Or, if so, other natural feedbacks, such as cloud cover, have always been sufficient to offset it.)

Then there’s this:

Several graphs and more information are available at the following websites: (Lindzen at MIT) (Soon, Harvard)

Some AGW advocates point out, as a basis for their concern about CO2, that Venus’ atmosphere is 95% CO2 and its surface is very hot.  But the atmospheric pressure on Venus is 90 times that of the earth and it is also closer to the sun. The equivalent atmospheric pressure on earth could be attained by being 1km under water.(quote from JoNova site).  With that pressure level, any gas would probably get hot. Also, what about Mars?  Mars atmosphere also happens to be about 95% CO2, and its surface is frigid.  (Of course atmospheric pressure on Mars is significantly less than on earth.)



CO2 might be harmful at levels as low as 1%  (an auditorium filled with occupants and poor fresh air ventilation, for example).  However, in the open atmosphere a 1% concentration of CO2 would imply that CO2 was 25 times higher than its current level.  At its current rate of growth CO2 is projected to be about 600 ppmv by 2099.  (A 1% level in the atmosphere corresponds to 9,750 ppmv, or 16 times the 2099 projection.)  The reported level of CO2 in submarines averages 3000-5000 ppmv with no apparent adverse health effects.

There may also be an issue with the accuracy of historic CO2 levels as determined from ice core measurements.  Professor  Zbigniew Jaworowski  claims (website below) that “more than 20 physico-chemical processes, mostly related to the presence of liquid water, contribute to the alteration of the original chemical composition of the air inclusions in polar ice”. If the professor is correct, then the now recognized historic ceiling of 280ppmv may be low. It may have actually been higher.

The level of carbon dioxide is increasing quite slowly. That, plus the lack of evidence clearly indicate that drastic economic policy is not warranted.  We should obviously continue to focus on enhancing reliable energy alternatives such as natural gas, nuclear, and water power and, of course continue research for better alternatives. (There are also good political reasons for doing this.)   Finally, US action, no matter how radical,  would  have little or no effect globally unless other populous countries, such as China and India, implement similar drastic steps. That’s unlikely to happen. The developing countries are already taking over the lead position as CO2 contributors. (Lord Monckton has more on the cost/benefit aspect.)

Richard S. Lindzen, atmospheric physicist and professor at MIT, said: (from Tom Nelson blog)

“It is difficult to see what, other than cupidity, could lead to any gathering momentum. In point of fact, nothing proposed would have any discernible impact on climate regardless of one’s views on climate science. Rather, the legislation would simply be another mix of payoffs and taxes. Public concern over climate is sinking. The science is increasingly acknowledged as being far from certain and even dubious. Scandals, while being denied, are clearly real. Claims of certainty are being endorsed by professional societies with no expertise (presumably under pressure from the environmental enthusiasts in the White House) while many actual scientists are acknowledging severe problems. The situation is quite a mess, and, I suspect that many politicians sense this. Supporting such legislation gets ever riskier. Atop all this, the developing world is more clearly and vocally identifying carbon control with attempts to stifle desperately needed development — which is to say that the issue is developing a patina of profound immorality”.

“Skeptic” is used to identify those who are doubtful that man is causing global warming.  However, Professor Lindzen makes clear that – to be skeptical of a proposition it must at least be plausible, and the anthropogenic global warming “theory” is not.

There is no evidence for the AGW claim.  Actually, the only plausible proposition related to our current warming is that the past 150 years of temperature variation have been natural. After all, it was warmer during the Medieval Warming Period, as well as during several earlier periods in this intergalactic.  Our current warming, which began some 200 years before our industrial revolution, follows a 400 year cooling period known as “the little ice age”.  While it’s not terribly relevant yet,  there has been no statistically significant warming for the past 15 years.

In a rational world the proponents of man-made global warming, (“climate change”, “climate disruption”, etc.)  would be viewed (at least in polite company) as the “skeptics” or “deniers”.

What about all these other related concerns  – rising sea levels, melting ice and receding glaciers,  more violent earthquakes, hurricanes, droughts, gulf stream ‘slowdown’, suicides, crime, etc.?

Some of these issues (those which are not merely figments of the imagination) may indeed be influenced by global warming (although most fit better with astrology), but there is no evidence that human activities are responsible for our current warming. The best that can be concluded is that there has been warming (since the little ice age – so not a surprise) and within the range of natural variation.  There is no evidence that this warming has been unduly influenced by human activity.

We are right now still enjoying life in our interglacial periodso some melting ice and minor sea level rise is not unexpected. (see the website below for more information on this).  Our real problems will begin if/when there is no receding glaciers or ice melt – at that time we’ll clearly be well on our way into our 14th ice age cycle !

The sea level has climbed about 400 feet during our current interglacial period. It began its rise in earnest around the end of the last ice age.  The graph below is based on our current interglacial period, but probably characterizes sea level rise following earlier ice ages.  Notice that the increase appears to begin as the ice age is ending and basically tops out several thousand years before the interglacial period is over:

Image:Post-Glacial Sea Level.png

do not miss the link to the graphs near the bottom of the webpage referenced just above

Since the ice ages were not of the same durations a couple of million years ago, what other longer-term impacts might also be influencing climate change?

Most of us live in areas where we regularly experience four distinct seasons each year – brought on by the earth’s annual revolution around the sun.  But there are similar longer-term climate cycles also related to variations in the earth’s orbit.  The longest include the earth’s “tilt”and associated wobbles relative to its orbital plane and to the eccentricity of its orbit and its location in that orbit.  But these actions involve cycles with durations as long as 100,000 years and are probably sufficient to bring on ice ages.  Another, much longer cycle which probably also has some impact is the revolution of our entire solar system around our galaxy.  That’s a 250 million year cycle, probably with further special impacts where our somewhat skewed orbital plane intersects the milky way plane.

What about other climate theories and explanations?

Following are just a few, and their level of importance may be unrelated to the fact that I happened to come across them.  The last one, Svensmark, is (for me) the most interesting because his conclusions are the result of teamwork across a number of disciplines and his theory, which is based on data, links us more closely with our universe.  Keep in mind that no theory attempts to explain most climate variation. (A simple example:   each year we expect to experience the four seasons – as usual. If it’s fall, we know winter is next, and that spring and summer follow, but on what day exactly does one end and the next start?  How cold will it be this coming winter, how much snow and ice? how warm next summer?)   

Qing-Bin Lu, a physicist associated with three different Departments (Physics and Astronomy, Biology, and Chemistry) at Canada’s University of Waterloo, reports in a peer-reviewed paper that cosmic rays and chlorofluorocarbons (CFCs), both implicated in depleting the Earth’s ozone layer, are also responsible for changes in the global climate.   Lu’s recent paper is “dedicated to describing the new cosmic-ray-driven electron-induced reaction mechanism— or CRE model — of ozone depletion, which he contrasts with the conventionalphotochemical model of ozone depletion.” Lu concludes in his treatise that the global warming observed in the late 20th century was mostly caused by CFCs, modulated by CRE-driven ozone depletion, and that “with the decreasing emission of CFCs into the atmosphere, global cooling may have started in 2002.” (Websites below):

Recent research by J. McLean, C.R. de Freitas, and R.M. Carter demonstrates a close link between atmospheric temperatures with variations in the El-Nino-Southern Oscillation (ENSO) climatic factors.  (ENSO is a climate pattern that occurs across the tropical Pacific Ocean every three to seven years.)  The authors claim that their analysis explains a large part of the temperature variation so leaves little room for any substantial influence by humans.

Any other theories out there about what may be causing longer-term variations? 

Asteroids, comets and volcanic activity can have a significant impact on climate, although the earth has so far been sufficiently stable to always recover.  Just 13,000 years ago, near the end of our most recent ice age,  the Mammoth and Saber Tooth Tiger, along with some other species, disappeared. It’s a good bet that this had something to do with rapid climate change.  A little over 600,000 years ago the Yellow Stone super volcano went off.  It evidently did the same 1.2 million and 1.8 million years ago   – not a good trend! The earth hasexperienced numerous ice ages over the past few million years. About 65 million years ago an asteroid took out the dinosaurs, and about 250 million years ago volcanic activity in Siberia destroyed about 95% of all life on the planet. One revolution of the solar system around the Galaxy takes 250 million years.   Three revolutions ago (about 700 million years ago) the earth was a “snowball” and apparently remained that way for millions of years.–ugd040610.php

A recent theory on climate takes into consideration “outside” influences (cosmic rays) as well as our position in the Milky Way.  About two decades ago Henrik Svensmark and several associates, representing various scientific disciplinesincluding physics, astronomy, geology, and oceanography, came up with theory which attempts to explain climate change.  This theory involves solar activityits interaction with cosmic raystheir influence on the amount of low cloud cover, and our location in the Galaxy.  (Sunspot activity has long been recognized as having an impact on climate.)  According to Svensmark our little planet is more entwined with the universe than most of us realized. Also, whereas most climatologists view climate as a driver of cloud cover,  it may be more appropriate to view cloud cover as being a significant driver of climate.

Svensmark’s theory is backed by data showing strong correlations across millions of years and also by current data.  Svensmark and his group have also shown through experiment that aerosol buildup caused by the more energetic cosmic rays is possible. (More recently physicists at CERN have concluded the same.) In 1995, he predicted an approaching cooling period when everyone else was still concerned about global warming. As a consequence he has not been very popular with the AGW

Cosmic Rays which penetrate the earth’s atmosphere and have sufficient energy to impact the lower atmosphere create aerosols which contribute to cloud cover buildup. Increased cloud cover leads to cooling (more sunlight reflected back out to space).  Less cloud cover leads to warming.  Low clouds typically cover 60% to 65% of the earth’s surface.  Cosmic rays emanate from exploding stars.  The number of exploding stars, together with their proximity, the energy level of the cosmic rays, and the level of solar activity influence our climate.

When the sun is in an active period, (many sunspots) fewer cosmic rays are able to overcome the solar wind ( a stream of charged particles from the sun, mostly electrons and protons), so do not even reach the earth’s atmosphere.  During such periods there is less cloud cover and hence warming, and it is the reverse during periods of solar inactivity.  When the solar system, during its revolution around the Galaxy, is in or near one of the spiral arms there are likely more stars in the vicinity, hence likely to be more nearby exploding stars and therefore more cosmic rays. 

The first website below is a 6 part “YouTube” generated by Svensmark and associates. It includes more detail, and is an easily understood and enjoyable presentation.  Except for about the first minute of the first part, there are English subtitles but thereafter the audio is in English.  The second website is a CERN colloquium held by Jasper Kirkby for physicists, much of it related to the same climate data correlations relevant to Svensmark.    (Svensmark, 6 part youtube)           (CERN Colloquium)

Stephen Wilde has an interesting commentary on solar influence, which does not seem to conflict with Svensmark’s theory, at the site below:

Lord Monckton’s testimony to congress May 6, 2010:
It all sounds good, but there’s something really wrong with this picture.  Why am I not getting this slant from the news media?   Also, there are lots of intelligent people out there who still believe the CAGW claim.

The very formation of an International Panel on Climate Change implies that (like most governmental entities) its basic goal will be to survive and flourish.  If mankind cannot be blamed for influencing the climate, funding for the IPCC will lose out to other competing issues.  In addition, one of the UN’s goals is to push for global governance probably because it would expect to have a more substantial role in that scenario. The motivation of other entities in this cabal, while not as obvious, do exist.  The major news media (and some other institutions) supported the AGW claim from the beginning.   Most of the news media have an increasing credibility problem already, for other reasons.  Their credibility would be completely shot if they came out of the closet now on this one.  And they got into this box because of their makeup.   The major news media is mostly liberal, with a staff considerably more liberal than other citizens in the general population.  Positions on CAGW quickly split along political lines.  People in both groups, at least initially,  tend to go along with (and believe) the views of their peers.

Many politicians, and not only in this country, are also very attached to the CAGW concept.  “Never waste a crisis” has always been a good strategy for them.

Our country is basically bankrupt, thanks to our politicians, but imposing a huge tax to address their prior profligate actions, would normally shorten or end most of their careers.  It would be much more convenient for them if the basis for major tax increases could be justified because of some other crisis unrelated to their actions, and the more serious it sounds, the better. What’s more, in this case the politicians get to blame their citizens for the problem, our “selfish” use of fossil fuels.  How could we then complain about the high taxes needed to alleviate a problem we supposedly caused?

This is why so many of the skeptics are so rabid about “climate change”.  That old saying applies:  “If you’re not overwrought about this issue, you just don’t understand the problem!

Recall that “global warming” followed similar chants in the 70s of “global cooling”, has recently morphed to “climate change”, and will no doubt continue on to such things as “poor polar bears”, “ocean acidification” and/or “climate disruption”.  Who knows?  Sooner or later a real problem may even be uncovered.

A recent revelation by a scientist who was “on the global warming gravy train” provides a succinct overview:

 (denis ables – last update Otober 29, 2011 4:pm)
If you have constructive criticism, please contact me

Some reference books:


“The Resilient Earth”   (Doug L. Hoffman and Allen Simmons)

“The Chilling Stars: A Cosmic View of Climate Change”  (Henrik Svensmark & Nigel Calder

“Unstoppable Global Warming: Every 1500 Years”   (Singer & Avery)

“Climategate: The Crutape Letters (Vol I)”  (Mosher)

“The Great Global Warming Blunder: How Mother Nature ….”  (Roy Spencer)

“Climate: The Counter Consensus” (Stacey International)  (New Zealand Professor Robert M Carter)

“Slaying the Sky Dragon: Death of the Greenhouse Gas Theory”  (T.Ball, C. Johnson, M.Hertzberg,J.A. Olsen, et al)

There are many good websites, a smattering of which appear below:   (Warren Meyer,  (John Costella, “Analysis of ClimateGate”)

   (the above site includes references to specific emails, so you can make your own decision)  (The Skeptics’ Handbook)  (Anthony Watts)  (Marc Morano)    An example of the many participants responding to a WUWT thread.  (Tim Ball on “Group Think”) (Tim Ball on aerosols)


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