Man and Global Warming
Edward Rouse Pryor
gobbledyhaha (at) juno.com
posted November 17, 2009
Summary: Just when public policy leadership has embraced as gospel the concept of man-induced atmospheric carbon dioxide as the cause of global warming, there is emerging evidence that CO2 and man have nothing to do with global warming or climate change. If the erroneous belief that atmospheric CO2 is responsible for global warming is incorporated into public policy legislation the unnecessary extra energy cost will be incalculable.
- There is strong evidence that the earth’s surface temperature is increasing.
- There is strong evidence that atmospheric CO2 levels are increasing and isotope analysis indicates that much of this increase comes from man’s activities – primarily the burning of fossil fuels.
- Since CO2 is a known ‘greenhouse effect’ gas there is a presumption that its increasing atmospheric presence is causing global warming or ‘climate change.’
- Careful analysis of the data assembled by the Intergovernmental Panel on Climate Change (IPCC) confirms that the earth is warming but that CO2 has nothing to do with it.
- The data indicate that whatever changes in temperature the earth experiences are a result of changes in radiation from the sun rather than the increases in trace greenhouse gases in our atmosphere like CO2.
The concept of anthropogenic (man induced) global warming began as speculation on the part of a few scientists who wondered if all the CO2 mankind was spewing into the atmosphere was being absorbed by plant life (or the oceans) or was building up in the atmosphere with possible unintended consequences. In the 1950’s scientists began precise measurements of the CO2 content of the atmosphere. After a number of years, it became evident that atmospheric CO2 was indeed increasing. Isotope analysis indicated that man’s burning of fossil fuels was the source of most of this build-up rather than ‘natural’ sources like volcanoes.
Using air bubbles in ancient ice cores from Antarctica and Greenland it was possible to go back in time some 650,000 years and determine historic atmospheric CO2 levels. Proxy methods such as deuterium ratios in the accompanying ice were used to estimate historic temperatures. There seemed to be a correlation between historic atmospheric CO2 levels and global temperature.
During World War II and the decades after, new techniques for measuring the earth’s surface temperature proliferated. Weather balloons became common. Sea weather buoys were added to ship measurements. New land weather stations were added. Satellites were put on line. The data from these different methods didn’t always agree. Some scientists contended the earth was not warming.
The Case for Global Warming
In the 1970s, a cadre of very competent scientists were convinced the earth was warming, and they knew atmospheric CO2 was increasing. The suggestion was that the warming was caused by the increasing CO2. But contrarians pointed out that the earth, at that time, was not warming.
In 1988 the IPCC was formed as a coalition of scientific and public policy advocates who defined ‘climate change’ as ‘a change in climate as a result of man’s activities.’ By now they had added the clearing of forests, cement making, cattle raising, etc., as well as the use of fossil fuels, to the list of man’s activities that cause global warming (now dubbed ‘climate change’). The case for anthropogenic climate change was clear and compelling to many scientists. Yet the opposition remained steadfast and centered around the argument that the earth was not warming.
The wider scientific community entered the debate. Biologists noticed the habitat of the arctic tern was moving north while Central American golden frogs were moving up the mountains to a cooler environment. Glaciologists noted that glaciers were thinning and receding. Sea Ice was forming later and melting sooner. Tundra was thawing. More and more proxy rising-global-temperature evidence poured in from many different lines of inquiry. Combined with the unquestioned increase in atmospheric CO2, the main thesis of the IPCC became more and more established: The earth was warming and it was being caused by man’s activities.
The tide of public opinion began to shift. The confrontational chairman of a major oil company retired and was replaced by a ‘go along to get along’ moderate. A leading republican senator and presidential aspirant announced: “The debate is over.” With most of the scientific community and much of government and the public behind them the IPCC consensus movement seemed unstoppable.
The Greenhouse Effect
We know the earth’s atmosphere has a ‘greenhouse effect’ because a ‘black body’ in space receiving an equivalent amount of solar radiation would be cooler, and because our day-to-night temperature excursions are more moderate than those experienced by bodies like mars and the moon with little or no atmosphere. It is the known existence of this ‘blanket’ that leads many scientists to believe that changes in its characteristics could lead to global warming.
A look at a handbook table of the constituents of the earth’s atmosphere will note that the ‘big three’ – nitrogen, oxygen, and argon – collectively comprise 99.9% of the atmosphere. None of these is a greenhouse gas. The next most abundant gas listed is CO2, at 0.038% and it is the first and apparently most important of the greenhouse gases. These handbook tables, however, are for ‘dry’ air and do not include water vapor which is some 13 to 33 times more abundant than CO2 in the atmosphere and is also a powerful greenhouse gas. Water vapor is a wild card in the atmosphere. Its percentage changes with altitude, temperature, pressure, and geographic location. Thus it is hard to pin down. This variability makes it hard to lay out a comparison of the relative ‘greenhouse effect’ importance of water vapor vs. CO2. Further compounding the problem is that on a molecular basis the ‘greenhouse effect’ for a gas is determined by its absorption bands within the infra-red spectrum and since there is a lot of overlap to the bands of CO2 and water vapor, again we get into an interpretation problem. If a band overlaps how do you allocate the ‘effect’– do you split the difference or do you allocate according to relative abundance? Estimates of the greenhouse effect of CO2 vary from 26% of the open sky (perhaps 10% overall) in one model cited by the IPCC down to about 0.15% in a model cited by contrarians. If CO2 plays a very minor role in the greenhouse effect (as some of these models would suggest) then dramatic increases in its presence in our atmosphere would have no effect on our climate and the greenhouse effect we observe would be overwhelmingly due to passive water vapor.
Aside from the modeling work by Kiehl and Trenberth [Ref. (3)] on the earth’s energy budget, there seems to be very little mainstream scientific inquiry or experimentation in this general arena.
The New Debate
From the beginning, CO2-caused global warming was at the low end of the scale of scientific confidence or surety. The entire case rested pretty much on two observational points. Both showed an apparent correlation between atmospheric CO2 and global temperature but neither had an established cause and effect relationship.
At this point we have a disagreement over the facts. On the one hand, water vapor is declared to be the dominant greenhouse gas with CO2 playing an almost insignificant role; while on the other hand CO2 plays a significant role along with water vapor. Based on this disparity we would have to concede that if the first case is true some factor other than anthropogenic changes to our atmosphere must be causing our globe to warm.
So let’s reframe the debate: The globe is warming (we all now agree). But we don’t really know what is causing it to warm. It could be increasing atmospheric CO2 or it could be something else. So let’s look at the observational evidence. The IPCC has plotted a composite earth surface temperature vs. time [Fig. (1)].
Figure 1. Clearly the earth’s surface temperature is rising over the long term just as the IPCC said. But what about the period from 1945 to 1979 ? Here the earth’s temperature was cooling while atmospheric CO2 was increasing as a result of the post-World War II industrial boom. How could this happen over a 35 year period if atmospheric CO2 causes global warming? One suggestion was that aerosols (particles) spewed into the air from the industrial boom caused a ‘dimming’ by reflecting the sun’s incoming radiation. Unfortunately while reflective particles from volcanic eruptions like Tamborra in 1815 (which caused “the year without a summer” in 1816) can cause short term dimming, soot particles (like stack emissions from coal power plants and older automobile exhausts) do just the opposite and absorb incoming radiation from the sun. [Image source: ref (2), Technical Summary, p37.]
So the first purported piece of observational evidence of CO2 causing global warming begins to disintegrate as CO2 and global temperatures diverge for a 35 year period.
Now lets look at the second piece of evidence, the ‘hockey stick’ graph made famous by Al Gore in his lecture series// documentary movie// book (Fig.2).
Figure 2. (Deuterium ratios in accompanying ice used as a proxy for temperature).
This graph shows peaks of global temperature over some 650,000 years coinciding with peaks in atmospheric CO2 content. The implication of course is that the extra CO2 is causing the higher global temperature and the minima are the various ‘glacier ages’. [Image source: ref (2), Technical Summary, p24.]
Actually the glacier age cycles are pretty well established as being caused by the near and far points in the geometric relation of the earth to the sun (the Milankovitch cycles) so attempting to pin those cycles on CO2 was a stretch at best. Actually the mechanism here is: As global temperature increases (as a result of increased solar irradiance) some of the vast quantity of CO2 dissolved in the world’s oceans is released into the atmosphere. Thus the increased CO2 is a result of rising temperature rather than a cause.
At the far right hand side of figure 2, note that CO2, methane, and nitrous oxide have risen to levels above that of ‘natural variability’ – probably as the result of man’s activities. But also note that global temperature is holding steady with no correlation to the continuously rising trace gases. This is another example of a ‘divergence’ demonstrating that there is such a small amount of these gases in our atmosphere that they have no effect on global warming.
The two main points of observational evidence used by the IPCC to ‘unequivocally’ demonstrate that CO2 is the cause of global warming are now in shambles… and it definitely looks like something other than atmospheric CO2 must be responsible for global warming. But what could that be? Obviously, increased solar irradiance.
The effect of the sun on global temperature is complex. We have the three different Milankovitch cycles, the solar sunspot cycle, and changes in solar surface intensity (like solar storms and flares) all affecting the earth’s incoming solar intensity. There is one highly publicized recent study that concludes that recent global warming is not related to increased solar irradiance [ref. (6)]. This paper selects from contradictory data from different satellites over the past two decades and extrapolates back in time. Even the global temperature data used differs markedly from the now well established IPCC baseline data. This paper, while painstakingly detailed, does not instill a high degree of confidence in its basic data or its conclusions.
On the other hand, figure 3 (from the IPCC data) shows another study of solar irradiance.
Figure 3. Although the scale is a little different from figure 1, this figure shows the increasing incoming radiation from the sun during the same time span that the temperature is rising in figure 1. Even a suggestion of the dip from 1945 to 1979 can be seen. Although all of the earth’s energy budget figures are too uncertain to draw definitive conclusions, it is interesting to note that if we use the change in total solar flux over the 20th century of about 0.8 watts per square meter from figure 3 as a percentage of the earth’s annual incoming solar radiation of 342 watts per square meter [from ref (3)], we get an increase of about a quarter of one percent. The average mean global absolute temperature increase over the same time span is also about a quarter of one percent. On the other hand an increase of about 25% in the CO2 content of the atmosphere during the same period shows no correlation. [Image source: ref (2), Chapter 2, p190]
These points of observational evidence make a convincing case:
- Atmospheric CO2 and other trace greenhouse gases are indeed increasing but collectively they are such a small component of our atmosphere that they have no effect on the earth’s temperature.
- Water vapor, which is much more abundant than CO2 in the atmosphere, causes the entirely passive ‘greenhouse effect’ that the earth experiences.
- Increases in the intensity of the sun cause global warming.
- Man-induced global warming is a modern myth.
The sooner we gain energy ‘independence’ the better. We should dramatically increase our effort to develop controlled thermonuclear fusion which is without doubt the long term energy solution. But we shouldn’t demonize and ban fossil fuels for the wrong reasons. The evolution and transition to alternative fuels will happen naturally based on technology, economics, and our wisdom in applying resources properly. In the meantime we should concentrate on helping emerging economies scrub their power plant emissions of particulate pollution rather than worrying about atmospheric concentrations of trace gases like carbon dioxide.
The scientific community has apparently become overwhelmed by the almost astounding amount of scientific effort from many different lines of inquiry that points to the conclusion that the globe is indeed warming. The cause of that warming, however, has not been extensively or critically examined by the scientific community. After all, it was an acknowledged assumption [Ref. (1)] of the founders of the IPCC that anthropogenic atmospheric carbon dioxide was the cause of global warming. Most researchers then simply confirmed the warming without examining the cause of that warming. As shown in this paper the assumption that CO2 was the cause was not very solid to begin with and data assembled by the IPCC for other purposes, when properly interpreted, strongly suggests that CO2 in not the cause.
Elizabeth Kolbert, in an effort to reinforce the thesis of anthropogenic global warming in her ‘Silent Spring’ like book, [Reference (5)], unintentionally said it all as she described a symposium in Iceland in 2004 with some 300 scientists present:
“Global warming is routinely described as a matter of scientific debate – a theory whose validity has yet to be demonstrated. The symposium’s opening session lasted for more than nine hours. During that time many speakers stressed the uncertainties that remain about global warming and its effects – on thermohaline circulation, on the distribution of vegetation, on the survival of cold-loving species, on the frequency of forest fires. But this sort of questioning, which is so basic to scientific discourse, never extended to the relationship between carbon dioxide and rising temperatures. The study’s executive summary stated, unequivocally, that human beings had become the ‘dominant factor’ influencing the climate.”
I rest my case.
Note: The writer has read literally hundreds of documents from the very scientific to the popular, to arrive at the thesis and to formulate the approach to its presentation and add to its fabric. Nearly everything used in the report including the three graphs came from reference 2. (the IPCC Fourth Assessment Report and its references). The other references below are listed because they are mentioned in the report.
- Intergovernmental Panel on Climate Change, Third Assessment Report: Climate Change 2001 (TAR) Working group 1: The Scientific Basis. (and references)
- Intergovernmental Panel on Climate Change, Fourth Assessment Report: Climate Change 2007 (AR4) Working Group 1 Report: The Physical Science Basis (and references and secondary references)
- J.T. Kiehl and Kevin E. Trenberth, Earth’s Global Mean Energy Budget, Bulletin of the American Meteorological Society, vol. 78, no. 2, Feb. 1997
- Al Gore, AN INCONVENIENT TRUTH, Rodale Books, 2006
- Elizabeth Kolbert, FIELD NOTES from a CATASTROPHE: Man, Nature, and Climate Change, Bloomsbury USA, 2006
- Mike Lockwood and Claus Frohlich, Recent directed trends in solar climate
forcings [etc], Proc. R. Soc. A (2008) 464, 1367-1385