Global Warming – It’s Not Anthropogenic CO2

By Alan Cheetham [updated 2007/06/24]

The global warming or climate change issue is assumed by most people to be caused by anthropogenic carbon-dioxide (CO2) emissions. What is not widely reported is that many scientists disagree with that assumption. The United Nations Intergovernmental Panel on Climate Change (IPCC) was founded in 1988 with the purpose of assessing “the scientific, technical and socioeconomic information relevant for the understanding of the risk of human-induced climate change.” -- i.e. its main goal builds in the assumption of “human-induced climate change”. The IPCC released climate change reports in 1990, 1996, 2001 and 2007. Although the IPCC has become the “definitive” authority and always makes statements regarding the definite human causation, it has never provided scientific evidence that anthropogenic CO2 is the cause, only output of models. The IPCC states: “Anthropogenic warming of the climate system can be detected in temperature observations.” [Ref. 24]. While temperature observations can detect changes they cannot provide attribution – other data are needed to correlate with the temperatures.

The Earth’s climate system is very complex and many attempts have been made to model it. There is an interaction of solar radiation, land, ocean, atmosphere, clouds, gases released by anthropogenic processes (agriculture, burning of carbon-based fuels) and natural earth processes (volcanoes, etc.). In this system, the sun provides the primary heating of the earth through solar radiation. Some of the solar radiation is reflected by clouds, thus reducing the heating from solar radiation (analogy: cloudy days in summer are typically cooler than sunny days because the clouds block heat from the sun). Heat is re-radiated by the Earth’s surface. Some of this heat is absorbed by “greenhouse gases” and re-emitted in the atmosphere, thus contributing to warming the Earth (analogy: cloudy days in winter are typically warmer than sunny days because the clouds keep heat in). The most important greenhouse gases in Earth's atmosphere include carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), water vapor (H₂O), ozone (O₃), and the chlorofluorocarbons (CFCs). In addition to reflecting sunlight, clouds are also a major greenhouse substance. Water vapor and cloud droplets are in fact the dominant atmospheric absorbers.

The sources of greenhouse gases (GHG) come from various sectors including transportation, industrial processes, power generation for residential consumption, agriculture and deforestation. According to the United Nations Food and Agriculture Organization (FAO), deforestation accounts for 25 to 30 percent of the release of GHG [Ref. 1]. The report states: “Most people assume that global warming is caused by burning oil and gas. But in fact between 25 and 30 percent of the greenhouse gases released into the atmosphere each year – 1.6 billion tonnes – is caused by deforestation.”.

From 1990 to 2000, the net forest loss was 8.9 million hectares per year. From 2000 to 2005, the net forest loss was 7.3 million hectares per year. The ten countries with the largest net loss of forest per year (2000 – 2005) are: Brazil, Indonesia, Sudan, Myanmar, Zambia Tanzania, Nigeria, Democratic Republic of the Congo, Zimbabwe, and Venezuela (combined loss of 8.2 million hectares per year). The ten countries with the largest net gain of forest per year (2000 – 2005) are: China, Spain, Viet Nam, United States, Italy, Chile, Cuba, Bulgaria, France and Portugal (combined gain of 5.1 million hectares per year). [Ref. 2].

Another FAO report released in November 2006 states that: “the livestock sector generates more greenhouse gas emissions as measured in CO2 equivalent – 18 percent – than transport…. the livestock sector accounts for 9 percent of CO2 deriving from human-related activities, but produces a much larger share of even more harmful greenhouse gases. It generates 65 percent of human-related nitrous oxide, which has 296 times the Global Warming Potential (GWP) of CO2…it accounts for 37 percent of all human-induced methane (23 times as warming as CO2) ” [Ref. 3]. So becoming vegetarian would have a greater effect in reducing greenhouse gases than driving a hybrid car.

The mistaken assumption is: temperatures have been increasing while atmospheric CO2 has also been increasing – therefore it must be CO2. But there is no direct evidence for this. The conclusion that the current global warming trend is significant and caused in a large part by humans is a result of computerized climate models -- Global Circulation Models (GCM’s). These models have been developed to model the human understanding of the complex processes involved in the earth’s climate. The following figure is from the IPCC report in February 2007 showing outputs from the models. It compares decadal temperature averages (black line) with the result of model simulations. The lower (blue) band shows the results of 19 simulations from 5 climate models using only the natural forcings due to solar activity and volcanoes. The upper (pink) bands matching the temperature lines show the results of 58 simulations from 14 climate models using both natural and anthropogenic forcings. This is the totality of the evidence that the warming is due to anthropogenic CO2 – the output of models.

However there are problems with the models, including the lack of sensitivity to solar irradiance. Many scientists do not agree that the certainty exists in the models’ ability to forecast the future climate and many present evidence that the models do not account for solar forcings that match reality. The IPCC states that: “The direct RF [radiative forcing] due to increase in solar irradiance is reduced from the TAR [Third Assessment Report]. The best estimate is +0.12 [Watts per square metre]” [Ref. 24]. The problem is that it is not currently understood how this small amount of change in solar irradiance during the solar cycle can influence the earth’s climate. In addition the 4AR states: “There is more uncertainty regarding the influence of solar forcing. In addition to substantial uncertainty in the timing and amplitude of solar variations on time scales of several decades to centuries, which has increased since the TAR although the estimate of solar forcing has been revised downwards”.

The following figure (below, left) is from the IPCC report [Figure 2.17, Ref. 24] showing the total solar irradiance. The adjacent figure (below, right) superimposes the model output figure (“Global”) from the above figure, onto the relevant part of the total irradiance figure. This shows the very poor correlation of the models with the actual solar irradiance, due to the erroneous assumption that there are no amplification factors that make solar radiance changes important in affecting the earth’s temperature. Just because we don’t understand how, doesn’t mean it isn’t so.

The National Research Council (National Academy of Sciences) produced a study called “Climate Change Science: An Analysis of Some Key Questions” [Ref. 4]. Here are a couple of relevant statements from that report:

“Because of the large and still uncertain level of natural variability inherent in the climate record and the uncertainties in the time histories of the various forcing agents (and particularly aerosols), a causal linkage between the buildup of greenhouse gases in the atmosphere and the observed climate changes during the 20th century cannot be unequivocally established. The fact that the magnitude of the observed warming is large in comparison to natural variability as simulated in climate models is suggestive of such a linkage, but it does not constitute proof of one because the model simulations could be deficient in natural variability on the decadal to century time scale.”

“Solar irradiance, the amount of solar energy striking Earth, has been monitored accurately only since the late 1970s. However, indirect measures of solar activity suggest that there has been a positive trend of solar irradiance over the industrial era… It is not implausible that solar irradiance has been a significant driver of climate during part of the industrial era, as suggested by several modeling studies.”

The sun provides the energy that warms the earth. And yet according to the NOAA National Climatic Data Center [Ref. 5] “Our understanding of the indirect effects of changes in solar output and feedbacks in the climate system is minimal”. The importance of fluctuations and trends in solar inputs in affecting the climate is inadequately modeled. Although the sun exhibits various types of energy related events (sunspots, solar flares, coronal mass ejections), sunspots have been observed and counted for the longest amount of time.

Sunspots vary on an approximately 11-year cycle. The climate models assume that the solar irradiance varies by a small amount based on the 11-year sunspot cycle. But there is much scientific disagreement as to this assumption. For example Scafetta and West [Ref. 6] state: “the models might be inadequate: (a) in their parameterizations of climate feedbacks and atmosphere-ocean coupling; (b) in their neglect of indirect response by the stratosphere and of possible additional climate effects linked to solar magnetic field, UV radiation, solar flares and cosmic ray intensity modulations; (c) there might be other possible natural amplification mechanisms deriving from internal modes of climate variability which are not included in the models”

The following figure compares the solar proxy 10Be concentration with a combined with filtered temperature record of the northern hemisphere from Beer et al [Ref. 7]. “If one computes the global and annual mean of solar forcing caused by the 100 kyr period of eccentricity one gets an amplitude of 0.12Wm~2 in the spherical mean. This value is too small to be detected in climate records. But, despite the tiny global forcing value, we can observe the 100 kyr frequency during the last 800 kyr in most paleoclimatic records. The global mean temperature changes between glacial and interglacial periods are large: about 20C for polar (Johnsen et al., 1995) and 5 for tropical regions (Stute et al., 1995). As a consequence the sensitivity for the 100 kyr Milankovitch forcing formally turns out to be about a 100 times larger than the values obtained from GCMs [emphasis added]. This result illustrates that using global and annual averages to estimate the climate sensitivity can be very misleading, especially when seasonal and local effects are significant. E.g. in the case of glaciers strong melting during the summer cannot be compensated by ice accumulation during the rest of the year. Beyond a certain threshold the winter temperatures have a vanishing influence on ice accumulation. So, constant small differences can be accumulated to large effects over long periods of time (10 kyr or half a period of the precessional cycle).”

The following figure is from a 2006 paper by Beer et al [Ref. 26], which states: “It is well known that the Sun plays the fundamental role as our energy source. However, it is still an open question what role the Sun plays in climate change.” And “the observed changes of the TSI over an 11-year cycle are very small (0.1%), corresponding to an average temperature change of 1.5 K of the photosphere and, on Earth, to a global forcing change of 0.25 Wm−2 (averaging over the globe and taking into account the albedo of 30%). This led many people to conclude that, even if the solar constant is not constant, the changes are too small to be climatically relevant without invoking additional strong amplification mechanisms. This conclusion seems to be premature, firstly because there is no doubt that there are positive feedback mechanisms in the climate system. A cooling for example, leads to growing ice sheets which increases the albedo and thus the cooling. The existence of feedback mechanisms is illustrated by the discussed glacial-interglacial cycles that are related to a very weak annual mean change in insolation.”

The figure shows the earth’s orbital eccentricity (panel (a) - the deviation from a circular orbit for the past 640,000 years with a clear period of ~100,000 years) and the corresponding sequence of glacial and interglacial periods found in the δD record from Dome C (Antarctica) (Spahni, 2005) that is an indicator of temperature shown in panel (b). The red curve in panel (b) reflects the summer insolation at 65◦N which includes, in addition to the eccentricity, the tilt angle (period of~40,000 years) and the precession of the Earth’s axis (period of ~20,000 years). “Note that the mean annual global insolation changes caused by the eccentricity are very small (<2.5 Wm−2)” and yet they cause significant climate changes.

The next figure shows the solar-related data representing the solar activity over the last 1000 years. “Three independent indices... The observed annual mean sunspot numbers (scale at right) also follows the 11-year solar activity cycle after 1700. The curve extending from 1000 to 1900 is a proxy sunspot number index derived from measurements of carbon-14 in tree rings. Increased carbon-14 is plotted downward (scale at left-inside), so increased solar activity and larger proxy sunspot numbers correspond to reduced amounts of radiocarbon in the Earth’s atmosphere. Open circles are an index of the occurrence of auroras in the Northern Hemisphere (scale at left-outside). [Ref. 8]

Figure 5-10: Sunspot Number and Solar Activity Proxy 1000 -2000

The following figure is from a NASA study [Ref. 9] showing total solar irradiance 1900 – 1995 which states: “The total energy change over a solar cycle is quite small, which has led many to argue that solar variability has little impact on climate.” The next figure superimposes the NASA total irradiance on the IPCC (Feb. 2007) temperature plot. This illustrates the problem with the models – they need CO2 to accomplish a similar correlation.

Although the sunspot cycle is approximately 11 years it varies and has generally been getting shorter over the last century. The following figure shows “Variations in the air temperature over land in the Northern Hemisphere (solid line) closely fit changes in the length of the sunspot cycle (dashed line). Shorter sunspot cycles are associated with increased temperatures and more intense solar activity. This suggests that solar activity is at least partly responsible for the rise in global temperatures over the last century” [Ref. 10]. The fact that the temperature – sun correlation is better than the temperature – CO2 correlation indicates the deficiencies of the models in being able to account for the solar influence. Short cycles generate high sunspot maxima, whereas long cycles are characterized by weaker sunspot activity. Friis-Christensen and Lassen have shown that the close correlation extends back to the 16th century [Ref. 11].

A study done by the director of the Centre for Sun-Climate Research at the Danish Space Research Institute (DSRI) [Ref. 12] looked at the influence of the sun’s magnetic field on cosmic rays and cloud formation and found: “The sun and the stars could explain most if not all of the warming this century, and he has laboratory results to demonstrate it. Dr. Svensmark's study had its origins in 1996, when he and a colleague presented findings at a scientific conference indicating that changes in the sun's magnetic field -- quite apart from greenhouse gases -- could be related to the recent rise in global temperatures….Svensmark and his colleague had arrived at their theory after examining data that showed a surprisingly strong correlation between cosmic rays and low-altitude clouds. Earth's cloud cover increased when the intensity of cosmic rays grew and decreased when the intensity declined…. Dr. Svensmark has never disputed the existence of greenhouse gases and the greenhouse effect. To the contrary, he believes that an understanding of the sun's role is needed to learn the full story, and thus determine man's role. Not only does no climate model today consider the effect of cosmic particles, but even clouds are too poorly understood to be incorporated into any serious climate model.”

While the cosmic ray – cloud connection is a contentious issue among some scientists, a study done at the State University of New York [Ref. 13] found that: "The solar wind... deflects cosmic rays. As the sun becomes more active and the solar wind intensifies, the theory predicts fewer cosmic rays should reach the earth and less cloud should form. Data from the past 20 years backs this up: as the sun has become more active, low-altitude cloud cover has dropped."

A study done by an Assistant Professor of Earth Sciences at Dartmouth University [Ref. 14] looked at the cycles of the sun’s magnetic fluctuations and found: “the sun's magnetic activity is varying in 100,000-year cycles, a much longer time span than previously thought, and this solar activity, in turn, may likely cause the 100,000-year climate cycles on earth… Sharma's calculations suggest that when the sun is magnetically more active, the earth experiences a warmer climate, and vice versa, when the sun is magnetically less active, there is a glacial period. Right now, the earth is in an interglacial period (in between ice ages) that began about 11,000 years ago, and as expected, this is also a time when the estimated solar activity appears to be high” This 100,000-year cycle is evident in the following figure, which shows temperature changes and CO2 concentrations over the last 450,000 years, derived from the Vostok ice cores. (Although it is hard to discern in the figure, the CO2 actually lags the temperature by several hundred years). The current global warming is not out of the ordinary in the long-term view.

The NOAA web page called “The Sun-Climate Connection” provides the following figure [Ref 15]. The article states: “Many scientists find that these correlations are convincing evidence that the sun has contributed to the global warming of the 20th century” (although even though the correlation between the sun and sea surface temperature (SST) is very high, they make the statement “while it is becoming clear that human activity is changing the climate today, solar activity may also be contributing to climate change” – but they give no supporting evidence that human activity is making a contribution.

A study by G. Tsiropoula [Ref. 16] provides further regional correlations between the sun and SST’s. He makes the statement “physical processes and/or linking mechanisms for this association are as yet unclear … current GCM simulations do not attribute a special role to the solar input variations on the climate change of the 20^th century”

A study by Claus Frohlich and Judith Lean [Ref. 17] displays the following figure showing the results of various studies documenting the increase in solar radiance in the last century. There are many studies and peer-reviewed scientific papers supporting the sun-climate connection.

Even the United Nations Food and Agriculture Organization shows similar evidence as illustrated in the following figure [Ref. 18].

A study by scientists at Armagh Observatory (Ireland) [Ref. 19] shows that the mean average temperature at Armagh is correlated to the length of the solar cycle. “We have found that it gets cooler when the Sun's cycle is longer and that Armagh is warmer when the cycle is shorter," said Dr Butler. In general, the more cosmic rays that reach the Earth, the more low cloud there is. However, a higher solar activity leads to lower cosmic ray flux and reduced low cloud. Low clouds cool the Earth by reflecting more solar radiation back into space, so a drop in the amount of low cloud contributes to global warming. High cloud does the opposite and tends to warm the Earth by reflecting more of the Earth's infra-red radiation back to the ground.” The following figure is from the study.

A study of solar irradiance at three locations in Oregon [Ref. 25] provides data showing a strong correlation between temperature and solar irradiance. The following figure is from the study.

Using temperature graphs from the NASA GISS database, and superimposing the above irradiance data yields the graphs shown below (details can be found at www.appinsys.com/GlobalWarming/solar_oregon.htm).

Burns Eugene Hermiston

Strong correlations between the sun and localized climatic effects have also been demonstrated. A study by Charles A. Perry [Ref. 20] shows such as precipitation and stream flow, including precipitation in Washington and Oregon as well as stream flow in the Mississippi river.

The planet Mars is also exhibiting a warming trend. A recent National Geographic article [Ref. 21]

states: “Simultaneous warming on Earth and Mars suggests that our planet's recent climate changes have a natural—and not a human-induced—cause…. Habibullo Abdussamatov, head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia, says the Mars data is evidence that the current global warming on Earth is being caused by changes in the sun. "The long-term increase in solar irradiance is heating both Earth and Mars," he said.”. A lack of long-term data on Mars prevents definitive knowledge, but William Feldman of the Los Alamos National Laboratory (involved with NASA's Mars Odyssey orbiter) says: “One explanation could be that Mars is just coming out of an ice age” [Ref. 22]. The principal investigator for the Mars Orbiter Camera said: “The images, documenting changes from 1999 to 2005, suggest the climate on Mars is presently warmer, and perhaps getting warmer still, than it was several decades or centuries ago” [Ref. 23]. All of which indicates warming caused by the sun.

What all these studies show is a very strong correlation between solar input and climate change. There is a lack of studies providing evidence for CO2 as the main causal factor – models provide the only evidence. The IPCC has made statements unsupported by science – that solar input is negligible. Given the stronger correlations between temperature change and solar influence, the case for anthropogenic CO2 is weak. It is at most a secondary factor. The scientific approach involves 1) observations of phenomena, 2) formulation of a hypothesis, 3) testing the hypothesis and 4) revising or rejecting the hypothesis based on predictions and further observations. The GCM’s were step two, based on the understanding of components of the earth’s climate system. Since the testing and further observations (step three) have shown the model deficiencies, it is time for step four – revising the understanding to accept that the solar irradiance is the major driving force in climate change.

[See www.appinsys.com/globalwarming for detailed analysis of more aspects of the global warming phenomena]

Alan Cheetham can be reached at: gw@appinsys.com

References:

[1] [http://www.fao.org/newsroom/en/news/2006/1000385/index.html]

[2] [http://www.fao.org/forestry/site/28821/en/]

[3] [http://www.fao.org/newsroom/en/news/2006/1000448/index.html]

[4] [http://books.nap.edu//html/climatechange/]

[5] [http://www.ncdc.noaa.gov/oa/climate/globalwarming.html ]

[6] Scafetta, N., and B. J. West, 2006. “Phenomenological solar contribution to the 1900-2000 global surface warming”. Geophysical Research Letters, doi: 1029/2005GL025539)

[7] “The role of the sun in climate forcing”, J. Beer, W. Mende, R. Stellmacher, Swiss Federal Institute of Environmental Science and Technology, Switzerland and Institute of Meteorology, Germany, Quaternary Science Reviews, 2000

[8] Professor Kenneth R. Lang, Tufts University [http://ase.tufts.edu/cosmos/view_picture.asp?id=119] (Courtesy of John A. Eddy.)

[9] “Solar Variability, Ozone and Climate” (Shindell 1999) [http://www.giss.nasa.gov/research/briefs/shindell_03/

[10] Professor Kenneth R. Lang, Tufts University [http://ase.tufts.edu/cosmos/view_picture.asp?id=116]

[11] Lassen, K. & Friis-Christensen, E.: Variability of the solar cycle length during the past five centuries and the apparent association with terrestrial climate. Journal of Atmos. Terr. Phys. 57 (1995)

[12] [http://www.canada.com/nationalpost/news/story.html?id=d2113c58-030a-4390-a12c-30f45d75dfa5&p=1]

[13] [http://www.newscientist.com/article/mg17523551.900-cosmic-rays-and-newborn-clouds-explain-one-of-the-mysteries-of-global-warming.html ]

[14] [http://www.sciencedaily.com/releases/2002/06/020607073439.htm]

[15] [http://www.research.noaa.gov/spotlite/archive/spot_sunclimate.html] The sun-climate connection illustrated is based on work by Reid, G.C., 1999. ‘Solar variability and its implication for the human environment’. (Journal of Atmospheric and Solar Terrestrial Physics 61, 3–14.)

[16] G. Tsiropoula, National Observatory of Athens, Institute for Space Applications and Remote Sensing, Athens, Greece – “Signatures of solar activity variability in meteorological parameters” (Journal of Atmospheric and Solar-Terrestrial Physics 65 (2003) 469– 482) [http://zeus.nascom.nasa.gov/~bfleck/jastp_publ.pdf]

[17] Claus Frohlich and Judith Lean, (World Radiation Center, Switzerland and E.O. Hulburt Center for Space Research, Naval Research Laboratory, Washington, DC) “Solar Radiative Output and its Variability: Evidence and Mechanisms” (Astronomy and Astrophysics Review) [http://rivernet.ncsu.edu/courselocker/PaleoClimate/FrohlichLeanSolIrdOverview1.pdf]

[18] [ftp://ftp.fao.org/docrep/fao/006/y5028e/y5028e01.pdf]

[19] “Sun's warming influence 'under-estimated'” says that the sun has been the main contributor to global warming over the past two centuries. [http://news.bbc.co.uk/2/hi/science/nature/1045327.stm ]

[20] Charles A. Perry (Water Resources Division, U.S. Geological Survey, Lawrence, Kansas USA) “Solar-Irradiance Variations and Regional Precipitations in the Western United States”

[http://ks.water.usgs.gov/Kansas/waterdata/climate/homepage.ijc.html]

[21] [http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html]

[22] [http://www.space.com/scienceastronomy/mars_ice-age_031208.html]

[23] [http://www.abc.net.au/science/news/stories/2005/1464931.htm]

[24] IPCC AR4 Report – The Physical Basis of Climate Change, 2007 [http://ipcc-wg1.ucar.edu/wg1/wg1-report.html]

[25] Trends In Direct Normal Solar Irradiance In Oregon From 1979-2003, Laura Riihimaki and Frank Vignola, Department of Physics, University of Oregon [http://solardat.uoregon.edu/download/Papers/DirectNormalTrends.pdf ]

[26] “SOLAR VARIABILITY OVER THE PAST SEVERAL MILLENNIA” J. BEER, M. VONMOOS and R. MUSCHELER (Swiss Federal Institute of Environmental Science and Technology, and NASA/Goddard Space Flight Center) Space Science Reviews, 2006 [http://www.eawag.ch/organisation/abteilungen/surf/publikationen/2006_solar_variability]