Carlin Economics and Science

For the reasons discussed in a journal article I published last spring, it is clear that the Catastrophic Anthropogenic Global Warming (CAGW) hypothesis does not satisfy the scientific method and thus does not explain global warming/climate change. So what does? The UN Intergovernmental Panel on Climate Change (IPCC) claims that they cannot think of any natural cause, so in their view it must be CAGW, but of course this cannot be correct given the negative findings using the scientific method. But if there is a natural cause, one of the IPCC’s principal but very weak arguments disappears anyway.

This post will sketch one such possible natural hypothesis that has the major advantage that it much better explains the available global temperature data since 1850 on the subject than all of the general circulation models used by the IPCC in their 2007 report.

A Major Natural Cause of Climate Change Needs to Be Much More Carefully Examined

The possible natural cause is that Earth’s climate is primarily but not exclusively determined by variations in the sun, the source of all our heat and light. These variations may in turn be determined by changes in the effects of planetary orbits on the center of mass of the solar system. As the IPCC agrees, there is also an important effect of major volcanic activity, particularly in the mid-latitudes. The IPCC claims, however, that solar variations are too small to explain the observed variations in global termperatures. This appears not to be the case because of indirect effects that the IPCC chose not to examine.

The best known (but not necessarily the only one) of these indirect effects occurs because cosmic rays reaching the Earth’s atmosphere from outer space increase the production of small particles by more than a factor of ten (see Svensmark and Calder and more recently CERN’s Kirkby et al.). This appears to increase the probability of formation of low clouds, which in turn influences the reflection of solar radiation back into space. This, in turn, appears to influence global temperatures since low clouds generally reflect a much higher proportion of solar radiation than the earth or its oceans do. Global climate also appears to be closely related to various oceanic cycles.

There Is an Amazing Relationship between the Various Solar System, Solar, Oceanic, and Climate Cycles

In fact, unlike the poor correlations between CO₂ and global temperatures, all these effects–of solar system mechanics on the sun, of solar variations on cloud formation and oceanic cycles, and of cloud formation and oceanic cycles on global temperatures–appear to have amazingly similar cyclical properties. So although the system is quite complex and very little has been done to understand it, this astronomical explanation of climate change appears to be a much more likely hypothesis than the IPCC’s CAGW hypothesis.

Current research suggests that the major solar/global temperature cycles include 20, 60, and approximately 1,000 years, and possibly a 200 or 210 year cycle, in addition to the 100,000 year astronomical/ice age cycle. So if, as it appears, the 60 year cycle reached its peak in the last decade, the 100,000 year cycle about 6,000 years ago, and the 1,000 year cycle either recently, or at the latest, in the next few decades, the prognosis for Earth’s climate under this hypothesis would appear to be for a colder rather than a warmer climate. The only major cycle that may defy this shift, but only for the next ten years, is the 20 year cycle, which appears to be nearing its low point. Various observations of Earth’s climate over the current Holocene period can be explained by assuming reasonable strengths and phases for the solar cycles that have been examined so far. The ice age 100,000 year cycle has long been attributed to astronomical cycles. Why not the shorter cycles as well? Why are they alone unrelated to astronomical cycles as the IPCC argues?

The Need to Move Climate Research Out of Its Current Pre-Copernican, Medieval Mindset on the Earth Alone

Unfortunately, the US has spent well over $100 billion on CAGW research over the past two decades and almost nothing on astronomical hypotheses. I would argue that at least 50 percent of US-funded research should be on non-CAGW hypotheses in order to have a balanced program that gives equal weight to all the possibilities. Surely a major portion of this 50 percent deserves to be used to explore astronomical hypotheses. Some of the obvious tasks are to better determine the major cycles of the solar system, the sun, the oceans, and global temperatures, what phase each one is in, and the extent to which and the mechanisms by which these cycles influence each other.

It is time for climate researchers to go beyond the confines of Earth to seriously examine astronomical sources of climate change. Astronomers have done so for hundreds of years in seeking to understand Earth’s role in the universe; climate researchers need to follow their lead rather than continuing to pretend that the rest of the universe plays only a minor role in climate. It defies common sense to think that the sun that provides all our light and heat has little impact on Earth’s climate. But this is what the IPCC and other CAGW supporters do to this day.

Unfortunately, the underlying reason that little serious research has been done on the astronomical hypotheses for climate change is the same reason that the results of using the scientific method in determining the validity of the CAGW hypothesis have been ignored–little funding is available for non-CAGW research. Research follows the money and for several decades the funding has been primarily for CAGW. Until this changes we are destined to repeat the mistakes, waste, and bad policy prescriptions that have characterized the last two decades in climate research.

Today my new paper on climate change science and economics was published in the International Journal of Environmental Research and Public Health, a peer-reviewed journal. The paper is unusual from a number of different perspectives.

Some Unusual Features

· The economic benefits of reducing CO2 emissions may be about two orders of magnitude less than those estimated by most economists because the climate sensitivity factor is much lower than assumed by the United Nations because feedback is negative rather than positive and the effects of CO2 emissions reductions on atmospheric CO2 appear to be short rather than long lasting.
· The costs of CO2 emissions reductions are perhaps an order of magnitude higher than usually estimated because of technological and implementation problems recently identified.
· CO2 emissions reductions are economically unattractive since the few benefits remaining after the corrections for the above effects are quite unlikely to economically justify the much higher costs unless much lower cost geoengineering is used.
· The risk of catastrophic anthropogenic global warming appears to be so low that it is not currently worth doing anything to try to control it, including geoengineering.

From a historical perspective, the paper builds on my Comments on Draft Technical Support Document for Endangerment Analysis for Greenhouse Gas Emissions under the Clean Air Act, prepared for the US Environmental Protection Agency in early 2009, by presenting an expanded version of a few portions of that material in journal article format, incorporating many new or updated references, and explaining the implications of the science for the economic benefits and costs of climate change control. It is also particularly noteworthy for appearing in a peer-reviewed journal rather than the “gray literature,” such as a report to EPA, where many skeptic analyses end up–something that warmists never fail to point out. Although this article was not written for EPA, it has major implications for the scientific validity (or lack thereof) of the December 2009 EPA Endangerment Finding and the economics that EPA and many economists have used to justify current efforts to regulate the emission of greenhouse gases under the Clean Air Act, cap-and-trade schemes, and other approaches to controlling climate change.

From a scientific perspective, the paper starts with a detailed examination of the scientific validity of two of the central tenets of the AGW hypothesis. By applying the scientific method the paper shows why these two tenets are not scientifically valid since predictions made using these hypotheses fail to correspond with observational data. (See primarily Section 2.)

From an economic perspective the paper then develops correction factors to be used to adjust previous economic estimates of the economic benefits of global warming control for these scientifically invalid aspects of the AGW hypothesis. (See primarily Section 2.) It also briefly summarizes many of the previous analyses of the economic benefits and costs of climate control, analyzes why previous analyses reached the conclusions they did, and contrasts them with the policy conclusions reached in this paper. (See primarily Section 5.) It also critically examines the economic costs of control. (See primarily Section 3.)

From a methodological perspective, the article argues that economic analyses of interdisciplinary issues such as climate change would be much more useful if they critically examine what other disciplines have to say, insist on using the most relevant observational data and the scientific method, and examine lower cost alternatives that would accomplish the same objectives. (See primarily Section 1.) These general principles are illustrated by applying them to the case of climate change mitigation, one of the most interdisciplinary of public policy issues. The analysis shows how use of these principles leads to quite different conclusions than those of most previous such economic analyses.

The Obama Administration has made many efforts to support its climate religion (climatism). Since this viewpoint has no basis in the scientific method, it is not science and would seem best characterized as religion. For a list of what the Administration believes they have done see page 27 here. The first item listed is $80 billion (with a “b”) for “clean and efficient energy in ARRA” (the American Recovery and Reinvestment Act of 2009, more commonly called the stimulus bill). Since most of this expenditure will not stimulate anything except the income of politically favored alternative energy providers and their suppliers and future higher cost energy for rate-payers, it is highly unlikely to be very stimulative for the economy as a whole.

The Administration Has Also Embarked on an Extensive Propaganda Campaign in Behalf of Climatism

Although not mentioned in the list of Administration efforts linked above but perhaps at least as worrisome, the Administration appears to have embarked on an extensive propaganda campaign to promote its climate religion to the general public at taxpayers’ expense. They have gone well beyond trying to defend their proposed greenhouse gas regulations by the US Environmental Protection Agency and are attempting to use other EPA programs and other agencies under their control to promote their viewpoint on this subject without the approval of and perhaps even the knowledge of Congress.

Recent news reports are that EPA is now proposing to require that information on greenhouse gas emissions by new automobiles be added to the mileage labels required on all new cars. Such Federal “educational” efforts are not limited to EPA, however. A recent news item reports that AmeriCorps is funding interns in Marin County Schools in California to assist with a climate change education program also designed to motivate students and their families to take voluntary energy efficiency actions to reduce their carbon footprint.

The Department of Education’s Plans for an “Education” Program

Even more recently, the Secretary of Education announced that his Department plans to “help advance the sustainability movement through education” through Federally subsidized school programs beginning as early as kindergarten that teach children about climate change and prepare them “to contribute to the workforce through green jobs.” His intention is that the Department’s efforts will “explain the science behind climate change and how we can change our daily practices to help save the planet.”

My comment is that one of the reasons that the Federal Government does not have primary responsibility for education is to avoid the possibility that it could directly inculcate the viewpoints of those currently in power on students throughout the country. But when funds for education at the state and local level are short, the Federal Government may believe that it has found a way around this restriction.

A National Park Service Effort

Most of this post, however, will deal with the expansion to the National Park Service (NPS), which may not have been so widely publicized but appears to be further along in its implementation so that it is easier to visualize what the “educational” efforts by other departments may look like when fully implemented. Because the Park Service is often viewed as an impartial source of objective information on natural history subjects, the NPS effort may carry added weight with citizens who view it, although the attempts to teach climatism to children as early as kindergarten may also be viewed as likely to be unusually “effective” by those desiring such an outcome.

The National Park Service’s Traveling Climate Change Exhibit

NPS/NASA Exhibit on Arrange for Change as photographed by Alan Carlin in NCNP (click to enlarge)

On a recent visit to the Visitor Center for North Cascades National Park near Newhalem, Washington, I encountered a large “traveling” exhibit panel entitled “Arrange for Change” with NPS and National Aeronautics and Space Administration (NASA) symbols indicating sponsorship. Rangers at the Visitor Center reported that it had been there for about a month and had come from Lewis and Clark National Historic Park and would soon move to another park. It was apparently intended as a temporary exhibit since the more permanent exhibit it replaced was still partially visible behind the large new exhibit in front of it. There were no handouts or other written material provided with the exhibit or available from those rangers asked so visitors would necessarily have to go by the exact contents of the exhibit in formulating their views on the subjects raised.

Last Section of NPS/NASA Exhibit on Arrange for Change (click to enlarge)

Briefly, the exhibit attempts to summarize the case for climatism with an emphasis on evidence from and impacts on national parks and ends by stating in the fourth of four sections (in the lower right of the written area of the exhibit and in the photograph above) that:

“Perhaps one of the best strategies for coping with change is for each person to become ‘carbon neutral’ in their daily lives. This can be accomplished by reducing energy use and investing in practices and alternate technologies that offset carbon emissons we are generating.”

Although the exhibit adheres closely to the standard climatism religion, and is therefore subject to the many general criticisms (see, for example, here and here) of it, I do have a number of questions and concerns about particular points made in the exhibit. First of all, the recommended strategy assumes a degree of altruism rarely seen in the real world since anyone who adopted the advice would have to engage in less energy-using activities and/or pay others to reduce their emissions through buying offsets. This is the reason that most advocates want mandatory standards so that everyone would have to endure similar losses whether they are altruistic or not.

The Rationale Is the Usual Climatism but without the Usual References

First Section of NPS/NASA Exhibit on Arrange for Change (click to enlarge)

The rationale for all this may be a little hard to understand by those not familiar with the climatism viewpoint. The first of the four sections in the exhibit states that:

“The scientific consensus is that global temperature in now rising at a rate unprecedented in the experience of modern human society (Arctic Climate Impact Assessment, 2004). Scientists also say most of the warming observed over the last 50 years is attributable to human activities.”

Accompanying these words is the Mona Loa CO₂ level chart showing steady increases over the years 1960 to about 2004.

This first section has a few problems. It relies almost exclusively on the authority of largely unspecified “scientists.” Since there is some evidence that temperatures rose at a similar rate in the 1920-30s, and, in fact for similar periods in the gradually rising 60 year cycles exhibited by global temperatures since the Little Ice Age (see here and my Comments, which can be downloaded from here), it is difficult to understand how the authors of the exhibit believe that global temperatures are “rising at a rate unprecedented in the experience of modern human society.” Perhaps more important is the lack of a citation (such as perhaps various IPCC reports) for the even more doubtful statement that most warming over the last 50 years is due to human activities. The implication of the Mona Loa chart would seem to be that the increasing levels of CO₂ are due to human activities, although this is certainly not stated and highly doubtful. Finally, no mention is made of the alternative hypothesis that the rise in CO₂ levels is an effect of rising ocean temperatures sometime in the past rather than anything humans may have done since rising ocean temperatures mean that the oceans cannot hold as much CO₂.

Exhibit Says Wildland Fires Have Increased–But Is This a Result of a Policy Change?

Lower Left Section of NPS/NASA Exhibit on Arrange for Change (click to enlarge)
The lower left section is entitled “Changes Disrupt Park Use.” The text states that:

“Higher temperatures in spring and summer and earlier melting of the snow pack in recent years have contributed to an increase in the frequency and duration of wildland fires. This increase in wildfires often causes park facilities to close. The 2006 fire season set a 45-year-high in the number of acres burned. 2006 was also the hottest January through July on record in America’s parks. In many parks, wintry weather is beginning later and ending earlier. Although this makes for a longer season of hiking and camping it reduces opportunities for recreational skiing and other winter sports due to inadequate snow cover. These impacts have economic implications.”

This section also has pictures of a plume from a forest fire and a cross-country skier.

No source is given for the temperature statement; it does seem odd that the period January through July was chosen rather than a full year, which would seem to be slightly more relevant (but hardly conclusive for assessing whether there really has been climatic change). Presumably most fires occur in the late summer or early fall, which is excluded from the period referenced. Also, I thought that the Park Service had changed its views concerning the role of fires in parks and now regards naturally-originated fires as good rather than a target for suppression. In some cases it even carries out controlled burns. Could it be that the increase in the number of acres burned was the result of this change in policy rather than climate change? The exhibit does not explain. It should also be pointed out that attempts to control carbon emissions also have economic impacts–and quite likely little, if any, impact.

Exhibit Claims Climate Change Is Happening on the Basis of Two Pictures and a Cute Endangered Pika

Upper Right Section of NPS/NASA Exhibit on Arrange for Change (click to enlarge)

The upper right section is entitled “Climate Change Is Happening.” It shows two pictures labelled Northwestern Glacier, Kenai Fjords National Park, 1909 and 2005, respectively. The former appers to show a much larger glacier and more mountain snow than the latter. No month or day of the year is provided for either photograph. The text states:

“Warmer winters and longer, more intense periods of melting have increased the rate of glacial retreat in many parks, as demonstrated by the Northwestern Glacier in Kenai Fjords National Park. It is estimated by scientists from the U.S. Geological Survey that by 2030, many of the glaciers in Montana’s Glacier National Park will be completely gone. In Yosemite, the pike population is endanger of extinction as warming temperatures are shifting their cool habitat higher and higher on the mountainsides.”

A picture of a pika is provided.

There is undoubtedly some climate change occurring on Earth, just as there has been for billions of years, but this section of the presentation does not make a case for climate change due to human activity as opposed to natural forces. And unless there is change due to human activity, there is no basis for “solving” the “problem” by modifying human behavior. With regard to the claim in the exhibit that there has been climate change in the parks, since no month is given when the two photographs were taken it is not possible to say whether the change in mountain snow levels between them is due to differences in time of year or in climate.

Such is not the case, however, for the extent of the glacier since that is much less dependent on time of the year but is greatly dependent on the amount of precipitation in the form of snow. It is important to note that the year 1909 is at or near the low point in the 60 year natural climate cycle while 2005 is near the top of this natural cycle (see my Comments downloadable from here), so some or even all of the differences in the extent of the glacier may be explainable by the natural 60 year climate cycle or changes in snow precipitation rather than any change in human emissions. If so, there may be climate change, but not necessarily human-induced climate change.

Some Questions About the Appropriateness of Using Public Funds to Directly Influence Public Opinion on a Highly Partisan Issue

In addition to the substantive issues raised above concerning the statements in the exhibit, it is very important to question the appropriateness of having the exhibit in a national park, paying Americorps interns to teach climatism to students, or using Federal subsidies to teach climatism in the schools. The effort appears to be widespread enough in the Federal Government so that it may have been directed from the White House, but it is possible that these various efforts are the result of individual departments attempting to curry favor with the Administration by supporting known Administration viewpoints. It would be interesting, however, to learn just how widespread these efforts are in the Executive Branch and how much is being spent on them.

The critical question, it seems to me, is whether taxpayers should pay for trying to influence the opinions of park visitors or students concerning a highly partisan issue which has split the Democrats in Congress and united the Republicans in the Senate in opposition. The highly questionable views (see my Comments downloadable here) attributed to “scientists” presented by the exhibit make no effort to present a balanced viewpoint by the many scientists who have presented differing views on the subject. And if such attempts are made to influence public opinion is it not the Park Service’s and each school’s responsibility to present all viewpoints in a balanced way, which is presumably what they try to do with their many other presentations to the public/students? Have the Park Service and Americorps and the Department of Education become mere propaganda arms for the Executive Branch of the Federal Government? Since climatism is currently a highly partisan debate in Congress and some state legislatures, should these agencies use taxpayer funds to support one side of the debate with no mention of the opposing viewpoints?

I think the answer to these questions should be for Federal agencies to get out of the climate change education business. Big Brother should not be attempting to sell his religious views to students or park visitors. Since the Administration appears unlikely to do this on its own, probably the easiest way to implement such restrictions is to prohibit the expenditure of Federal funds for the purpose of promoting climatism to the public.

(One source added January 28, 2010)

One of the basic problems in reaching rational conclusions with regard to global climate change problems is that AGW proponents and skeptics largely use different data sources and very different analyses of the global temperature data to support their cases.


Global Temperatures According to NOAA (click to enlarge)
This first chart shows a typical global temperature chart similar to those often used by AGW supporters. Like most such charts, it represents global temperatures based on ground-based readings, and is apparently constructed by smoothing annual data. It shows the familiar “hockey stick” emphasizing the rise in temperatures since the mid-1970s that has become so familiar in AGW presentations.

The Satellite Data Shows What Appears to Be a Very Different Picture

And Using Satellite Data (click to enlarge)
AGW supporters almost never use satellite data on near-ground temperatures despite its availability since 1978. This second chart shows what appears to be a very different picture using it. One would think that the two sources of data would yield quite similar trends and have important similarities since they attempt to measure air temperatures so close to each other. But this appears initially not to be the case.

What the satellite data shows is a roughly flat trend with 3-5 year cycles from 1978 through about 1996. This cycle appears to be closely related to the El Nino Southern Oscillation (ENSO) which shows a very similar pattern. But the flat trend shows no obvious effects from the increasing atmospheric CO2 levels during this crucial period for the AGW’s point of view.

Then in 1998 there was a large spike in temperatures (which appears to be largely unexplained by anyone and has no obvious relation to changes in CO2 levels) that occurred just when the 3-5 year cycle might have been expected to bottom.

In the early 21st Century the same essentially flat pattern of 3-5 year cycles appears to reestablish itself in the satellite data but at a slightly higher temperature until a breakdown occurred in late 2007 back down towards what may turn out to be the original levels in the 1978-96 period.

So it appears that the the two charts suggest very different things. The AGW presentation obscures the 3-5 ENSO cycle and emphasizes what appears to be a fairly steady increase in temperatures from the 1970s on that makes the presumed influence of rising CO2 more plausible. The satellite chart, on the other hand, highlights the ENSO cycle and the abrupt changes in 1998, and makes the presumed influence of CO2 appear implausible.


Ground (blue) and Satellite (red) Temps (click to enlarge)
If both monthly ground-based and satellite data are combined on one chart (the third one), there appear to be more similarities between the two charts. In the 1978-96 period the ground data (highlighted in blue) appears to increasingly diverge from the satellite data and increases during the 1978-96 period rather than showing the flat trend exhibited by the satellite data. But there appear to be substantial similarities between the two data sets thereafter.

So in the ground-based case there appears to be a gradual rise in temperatures during 1978-2005 which appears to be at least somewhat consistent with the increase in CO2 levels. And in the satellite case there is no visual support for a gradual increase or any apparent role for CO2 during the whole period.

Increasing Reason to Question the Ground-based Data

There is increasing reason to question the basic ground-based data as well as the rationale for the AGW interpretation of it. There have been a number of studies suggesting that ground-based data is severely compromised by urban heat island effects, inappropriate placement of monitors that increase recorded temperatures over what they would have been if the instruments had been properly cited, and the drop-out of a large number of rural stations in the 1970s. The urban heat island effects arise because urban areas retain heat much more than non-urban areas and many urban areas in the US and elsewhere expanded rapidly in the late 20th Century. This may have been accentuated by the decision to drop many rural sites. So prior to 1997 the upward bias in the ground-based temperatures may represent little more than the results of these three effects.

In addition, there are many reports that the ground data has been subjected to substantial and often repeated adjustments for various factors. In the case of the crucial HadCRUT ground-based data developed in Great Britain, and the source most often used by the United Nations, the custodian has refused to release the data and their manipulations of it and recently said that they have not even retained the original observations. So it now appears to be impossible to reconstruct exactly what the custodian may have done with the data despite the fact that this is the data most often relied upon by AGW supporters to make their case. Finally, the heavily smoothed ground-based annual data appears to hide rather than illuminate what has actually happened.

For more information on the problems with the ground-based data see here and more recently here.

So what should we make of this seemingly perplexing but very important battle of the global temperature charts? A reasonable interpretation is that the AGW charts cleverly hide the ENSO cycle through use of annual data, heavy smoothing, and questionable data and show a gradual increase in temperatures starting in the mid-1970s due to an upward bias in the data. But If monthly data are used, no smoothing is carried out, and the increasing ground-based temperature data during 1978-96 is assumed to be replaced with the flat trend line shown in the satellite data, the two data sources would actually appear to be quite consistent except that the ground-based data is generally higher than the satellite data. This difference may also be due to biased ground-based data. But if this substitution is made, the same major features would appear in both cases.

I believe it is incumbent on AGW supporters to show why the monthly satellite data without smoothing should not be used since it avoids using the suspect ground-based data and provides a more accurate picture of what actually happened. It is they, after all, that are asking the world to spend astronomical amounts on the basis of their hypothesis. If this is done, their “hockey stick” disappears and along with it the familiar AGW arguments for their hypothesis. This is not proof of biased 1978-96 ground data but appears to be the most reasonable explanation of the remaining differences between the two data sources.

The satellite data may have its own problems, of course, but there is reason to believe that it may be far more reliable than the ground-based data. There are also two independent data services which have delivered very similar data. A much more detailed analysis of what the satellite data can tell us can be downloaded from here, which is also the immediate source of the charts above.

On June 30 I appeared on the Glenn Beck show, where I showed two charts from my Comments on the proposed EPA endangerment finding report. Although these two graphs do not prove or disprove the existence of significant global warming as a result of increasing levels of carbon dioxide in the atmosphere (the principal UN hypothesis), they are readily understandable and suggest that substantial such warming from this cause is implausible.

UN Temperature Projections Compared with Measured Global Temperatures

Comparison of UN Projections with Temperatures (click to enlarge)

The first graph compares some of the United Nations IPCC model projections (in red, orange, and brown) and actual global temperature surface (green) and satellite (blue) measurements. There is also a yellow line representing the UN’s projection of future temperatures if there were no further human caused carbon dioxide (CO2) emissions. The vertical scale shows temperatures and the horizontal scale calendar years.

It is quite evident that there appears to be an increasing divergence between the UN projections and the global temperature measurements. The obvious question is how this could be if the UN projections are correct. We cannot rule out a brief divergence between projections and temperatures, of course, based on other random and unexplained factors.

But the other seemingly more likely possibility is that the UN projections are substantially inaccurate and exaggerate the projected temperature increase on the high side. Subsequent temperature measurements (not shown here) do not resolve this discrepancy.  If the projections are substantially too high, perhaps they do not deserve to be taken as seriously as many people now do.

Decreasing Measured Temperatures and Increasing CO2 Levels

Comparison of Decreasing Temeratures to Increasing CO2 (click to enlarge)

The second graph also shows global temperatures by calendar year for the period 2002 until mid-2008, but superimposes on this chart yearly atmospheric CO2 levels (shown in green) by year. Since there are two principal sources of global temperature data, surface (shown in black) and satellite (shown in red) measurements, both are shown along with trend lines for each. Inspection of the data shows that while temperature data were trending down over this period, CO2 levels were steadily increasing.

This again suggests that either there was a brief, random, divergence from what would be expected if the UN hypothesis concerning the effects of increasing CO2 levels on temperatures are correct, or that the UN models and hypothesis are simply incorrect.   The brief divergence possibility appears implausible because very similar divergences have appeared previously during the periods 1880 to 1910 and 1940 to the mid-1970s. In fact, the changes in global temperatures appear to be cyclical and to be very similar to the pattern of the Pacific Decadal Oscillation (PDO) which has roughly a 60 year cycle (with 30 up years followed by 30 down years). This leaves the other possibility–that something may be wrong with the UN’s basic hypothesis that CO2 levels are the major determinant of global temperatures since the UN models do not show any such cycles and do not explain the down years from 1940 to the mid-1970s or since 1998.

And if their hypothesis is incorrect, their proposed solution, decreasing CO2 emissions into the atmosphere, would not be effective in preventing increases in global temperatures. At the very least there would appear to be other important factors influencing global temperatures besides CO2 levels that the UN has not considered.  It is important that we understand what these other factors might be before committing ourselves to trying to reduce CO2 emissions at the cost of many trillions of dollars.  To proceed now with reducing CO2 emissions would not only be very expensive but possibly largely futile as well.