Thursday, August 23, 2007

"Warmism": The Myth of Anthropogenic Global Warming

"Warmism" is the belief that the warming trend which began in the latter half of the twentieth century (a.k.a. "global warming") is mainly an artifact of human activity. Warmism is a "religious" and political cause; it is not based on "scientific consensus." (Science and consensus are antithetical, anyway.) I will not venture to summarize here the mountain of evidence against warmism. (Links to some of the evidence are here, in the section headed Climate Change.) I will focus, instead, on
  • "smoking gun" evidence against warmism
  • alternative and compelling explanations of the warming phase that we have been through, but which may be about to end.
(Some of the graphs that support my argument may be hard to read. To enlarge a graph, just right-click on it and select "open link in a new tab.")

I begin with Steve McIntyre's post about the "spaghetti graph," which purports to show various estimates of changes in the temperature of the Northern Hemisphere since about 900 A.D. In fact, only three of the twelve series plotted in the "spaghetti graph" go back as far a 900 A.D.. And only one of those -- the Moberg series -- goes back as far as 1 A.D. Here, I splice NASA's estimates of Northern Hemisphere temperatures to the Moberg series and compare the result to the world's population (a proxy for "human activity"):
Notes and sources: The values on the x-axis are years A.D. The temperature anomalies (variations in degrees C from the mean for a base period) are plotted in 50-year intervals, except that the first year in the Moberg series (linked above) is 1 A.D. I re-indexed the Moberg series to give it a value of 1 in 1 A.D. (The underlying index is based on the mean value for 1961-90.) I re-indexed NASA's estimates of temperatures in the Northern Hemisphere for 1900, 1950, and 2000 to make the value for 1900 coincide with the value of the re-indexed Moberg series in that year. I indexed population estimates to a value of 1 in year 1 A.D. Population estimates for selected years from 10000 B.C. through 1950 A.D. are taken from "Historical Estimates of World Population" (U.S. Census Bureau). I averaged the "summary" values from that source to obtain estimates for the years plotted from 1 A.D. through 1900 A.D. I took population estimates for 1950 and 2000 from "Total Midyear Population of the World: 1950-2050" (U.S. Census Bureau).
Oops! First, temperatures rise while population falls; next, population rises while temperatures fall; finally, late in the twentieth century, temperatures rise while population rises. Well, perhaps it takes a while (centuries?) for human activity to affect Earth's temperature. Perhaps, for a long time, there were simply "too few" humans and too little of the "wrong kinds" of human activities. That is the story that "warmists" would like us to believe, though they concocted that story only after seizing upon the apparent relationship between human activity (i.e., the satisfaction of wants through economic endeavor) and the warming trend of the late twentieth century. Let us turn to that relationship.

Taking population as a proxy for the kind of human activity that generates carbon dioxide emissions -- the chief culprit in the "greenhouse" theory of global warming -- one would expect temperatures to rise with population. And so, it seems, they have -- in the recent past:
Notes and sources: Again, the x-axis represents years A.D. I re-indexed NASA's estimates of U.S. and global temperature anomalies (base period 1951-80) to equal 1 in 1880 A.D. (I used the global series that represents only meteorological stations, though I suspect its validity, given the disparity in the U.S. and global trends. That disparity cannot be explained simply by the fact that the U.S. represents only two percent of Earth's surface, as Steve McIntyre points out in these three posts -- UPDATES: plus this more recent one, and this and this one.) I drew estimates of sunspot activity from this NOAA source, and indexed them so that the value for 1880 equals 1. The sources for population estimates are as above, except that I estimated the value for 1880 by interpolation from the values for 1850 and 1900. I then indexed the population series so that the value for 1880 equals 1. Population is a proxy for carbon-dioxide emissions, though there hasn't been a one-to-one relationship between population and emissions of carbon dioxide since 1980 (at least), according to the National Energy Administration's "World Energy Use and Carbon Dioxide Emissions: 1980-2001." (See the figure on page 13 and related text.) It seems that population has been growing faster than carbon dioxide emissions: 1.6 percent a year as against 1.2 percent a year.
Oops, again! It seems that temperatures not only have risen with population since the 1960s or 1970s, but also have risen with solar activity. Solar activity (inversely) affects the level of cosmic radiation reaching Earth; cosmic radiation, in turn, (directly) affects cloud formation; and cloud formation, in turn, (inversely) affects temperatures. (See this for an explanation.) In sum, more solar activity means higher temperatures, but it takes about seven years for changes in solar activity to be reflected in temperature changes. (See this.)

It should be quite evident by now that the warming trend of the past thirty-odd years merely coincides with the rise in human activity (as measured by population) but is not explained by the "greenhouse" effect that supposedly arises from human activity. (The "greenhouse" effect is in fact a physically impossible phenomenon, according to this source). There are alternative and compelling alternative explanations for the warming trend, including the influence of solar activity summarized above, as well as alternative (and far less alarming) estimates of the likely rise in temperatures over the next several decades. (Again, for more on such matters, go to the Climate Change section of this page).

The nail in the coffin of warmism -- as far as I am concerned -- is the fact that the present warm period is a mere blip on Earth's temperature chart. Consider, for example, the following reconstruction of temperatures in the Northern Hemisphere for the past 11,000 years (the red-blue curve):
Source: "Climate Patterns in Northern Finnoscandia during the Last Millenium" (figure 6).
Two articles on paleoclimatology at Wikipedia accurately reflect what I have read elsewhere about long-run climate change. It takes only two figures to put things in perspective. First, a reconstruction of ice-core temperatures (blue line) at Vostok, Antarctica (the present is at the left):
Source: This figure from "Paleoclimatology" at Wikipedia.

The next chart shows that the current cyclical era began about 500,000 years ago. (The present is at the right in this graph.) The expansion of the time scale from 10,000 years ago to the present puts the present warm spell in perspective. It is not extraordinarily warm, by any standard. It is, rather, only a small segment of a the "spike" that typically signals the end (or beginning) of a 120,000-year cycle. The present spike has thus far lasted about 10,000 years, a mere blink of the eye in geological time. It does not look like a spike in the graph because of the expansion of the time scale for the period from 10,000 years ago to the present.
Source: This figure from "Geologic Temperature Record" at Wikipedia.
Two complementary theories explain climate change. First, there are
Milankovitch cycles...the collective effect of changes in the Earth's movements upon its climate, named after Serbian civil engineer and mathematician Milutin Milanković. The eccentricity, axial tilt, and precession of the Earth's orbit vary in several patterns, resulting in 100,000 year ice age cycles of the Quaternary glaciation over the last few million years. The Earth's axis completes one full cycle of precession approximately every 26,000 years. At the same time, the elliptical orbit rotates, more slowly, leading to a 21,000 year cycle between the seasons and the orbit. In addition, the angle between Earth's rotational axis and the normal to the plane of its orbit changes from 21.5 degrees to 24.5 degrees and back again on a 41,000 year cycle. Currently, this angle is 23.44 degrees.
Then, as outlined above, there is the varying influence of solar activity on cosmic radiation as the Solar System traverses the Milky Way. This is from an article ("The Real Deal?") in the National Post:

Astrophysicist Nir Shariv, one of Israel's top young scientists, describes the logic that led him -- and most everyone else -- to conclude that SUVs, coal plants and other things man-made cause global warming.

Step One Scientists for decades have postulated that increases in carbon dioxide and other gases could lead to a greenhouse effect.

Step Two As if on cue, the temperature rose over the course of the 20th century while greenhouse gases proliferated due to human activities.

Step Three No other mechanism explains the warming. Without another candidate, greenhouses gases necessarily became the cause.

Dr. Shariv, a prolific researcher who has made a name for himself assessing the movements of two-billion-year-old meteorites, no longer accepts this logic, or subscribes to these views. He has recanted: "Like many others, I was personally sure that CO2 is the bad culprit in the story of global warming. But after carefully digging into the evidence, I realized that things are far more complicated than the story sold to us by many climate scientists or the stories regurgitated by the media.

"In fact, there is much more than meets the eye."

Dr. Shariv's digging led him to the surprising discovery that there is no concrete evidence -- only speculation -- that man-made greenhouse gases cause global warming. Even research from the Intergovernmental Panel on Climate Change-- the United Nations agency that heads the worldwide effort to combat global warming -- is bereft of anything here inspiring confidence. In fact, according to the IPCC's own findings, man's role is so uncertain that there is a strong possibility that we have been cooling, not warming, the Earth. Unfortunately, our tools are too crude to reveal what man's effect has been in the past, let alone predict how much warming or cooling we might cause in the future.

All we have on which to pin the blame on greenhouse gases, says Dr. Shaviv, is "incriminating circumstantial evidence," which explains why climate scientists speak in terms of finding "evidence of fingerprints." Circumstantial evidence might be a fine basis on which to justify reducing greenhouse gases, he adds, "without other 'suspects.' " However, Dr. Shaviv not only believes there are credible "other suspects," he believes that at least one provides a superior explanation for the 20th century's warming.

"Solar activity can explain a large part of the 20th-century global warming," he states, particularly because of the evidence that has been accumulating over the past decade of the strong relationship that cosmic- ray flux has on our atmosphere. So much evidence has by now been amassed, in fact, that "it is unlikely that [the solar climate link] does not exist."

The sun's strong role indicates that greenhouse gases can't have much of an influence on the climate -- that C02 et al. don't dominate through some kind of leveraging effect that makes them especially potent drivers of climate change. The upshot of the Earth not being unduly sensitive to greenhouse gases is that neither increases nor cutbacks in future C02 emissions will matter much in terms of the climate.

Even doubling the amount of CO2 by 2100, for example, "will not dramatically increase the global temperature," Dr. Shaviv states. Put another way: "Even if we halved the CO2 output, and the CO2 increase by 2100 would be, say, a 50% increase relative to today instead of a doubled amount, the expected reduction in the rise of global temperature would be less than 0.5C. This is not significant."

The evidence from astrophysicists and cosmologists in laboratories around the world, on the other hand, could well be significant. In his study of meteorites, published in the prestigious journal, Physical Review Letters, Dr. Shaviv found that the meteorites that Earth collected during its passage through the arms of the Milky Way sustained up to 10% more cosmic ray damage than others. That kind of cosmic ray variation, Dr. Shaviv believes, could alter global temperatures by as much as 15% --sufficient to turn the ice ages on or off and evidence of the extent to which cosmic forces influence Earth's climate.

In another study, directly relevant to today's climate controversy, Dr. Shaviv reconstructed the temperature on Earth over the past 550 million years to find that cosmic ray flux variations explain more than two-thirds of Earth's temperature variance, making it the most dominant climate driver over geological time scales. The study also found that an upper limit can be placed on the relative role of CO2 as a climate driver, meaning that a large fraction of the global warming witnessed over the past century could not be due to CO2 -- instead it is attributable to the increased solar activity.

Finally, there is this compelling evidence against warmism (from "Look to Mars for the Truth on Global Warming," also in the National Post):
"One explanation could be that Mars is just coming out of an ice age," NASA scientist William Feldman speculated after the agency's Mars Odyssey completed its first Martian year of data collection. "In some low-latitude areas, the ice has already dissipated." With each passing year more and more evidence arises of the dramatic changes occurring on the only planet on the solar system, apart from Earth, to give up its climate secrets.

NASA's findings in space come as no surprise to Dr. Habibullo Abdussamatov at Saint Petersburg's Pulkovo Astronomical Observatory. Pulkovo -- at the pinnacle of Russia's space-oriented scientific establishment -- is one of the world's best equipped observatories and has been since its founding in 1839. Heading Pulkovo's space research laboratory is Dr. Abdussamatov, one of the world's chief critics of the theory that man-made carbon dioxide emissions create a greenhouse effect, leading to global warming.

"Mars has global warming, but without a greenhouse and without the participation of Martians," he told me. "These parallel global warmings -- observed simultaneously on Mars and on Earth -- can only be a straightline consequence of the effect of the one same factor: a long-time change in solar irradiance."

The sun's increased irradiance over the last century, not C02 emissions, is responsible for the global warming we're seeing, says the celebrated scientist, and this solar irradiance also explains the great volume of C02 emissions.

"It is no secret that increased solar irradiance warms Earth's oceans, which then triggers the emission of large amounts of carbon dioxide into the atmosphere. So the common view that man's industrial activity is a deciding factor in global warming has emerged from a misinterpretation of cause and effect relations."

Dr. Abdussamatov goes further, debunking the very notion of a greenhouse effect. "Ascribing 'greenhouse' effect properties to the Earth's atmosphere is not scientifically substantiated," he maintains. "Heated greenhouse gases, which become lighter as a result of expansion, ascend to the atmosphere only to give the absorbed heat away."

The real news from Saint Petersburg -- demonstrated by cooling that is occurring on the upper layers of the world's oceans -- is that Earth has hit its temperature ceiling. Solar irradiance has begun to fall, ushering in a protracted cooling period beginning in 2012 to 2015. The depth of the decline in solar irradiance reaching Earth will occur around 2040, and "will inevitably lead to a deep freeze around 2055-60" lasting some 50 years, after which temperatures will go up again.

To paraphrase Shakespeare: The warming, dear reader, is not in ourselves, but in our stars.

Related posts:
Re: Climate "Science"
More Evidence against Anthropogenic Global Warming
Yet More Evidence against Anthropogenic Global Warming
Anthropogenic Global Warming Is Dead, Just Not Buried Yet

Related reading:
A 2000-Year Temperature Reconstruction Based on Non-Treering Hypotheses (in which the Medieval Warm Period looms much larger than the current warm spell and the irrelevance of tree-ring data is explained)
Aliens Cause Global Warming and other speeches by Michael Crichton
Are Carbon Emissions the Cause of Global Warming ? (No. Moreover, global warming has reversed.)
Climate Audit (a blog by Steve McIntyre of the M&M project -- see below -- and a comprehensive resource for those interested about the science of global warming, as opposed to the religion of it)
Climate Change Chaos (two posts about alternative explanations of "global warming")
Climate Change 2007: Climate Change Impacts, Adaptation, and Vulnerabilities (IPCC's latest contribution to the scare about global warming)
Climate Patterns in Northern Fennoscandia during the Last Millenium (the present episode as a blip in Finnish temperature patterns dating back 7,640 years)
Climate Warming Is Naturally Caused and Shows No Human Influence
Clouding the Issue (the effect of the "Asian Brown Cloud" on "global warming")
Cool Heads Required (Spiked! survey article about climate change)
A Consensus about Consensus
Consensus, What Consensus? Among Climate Scientists the Debate Is Not Over
Cosmoclimatology: A New Theory Emerges (Henrik Svensmark's theory of climate change as being caused mainly by the level of cosmic radiation reaching Earth; supported by this article; criticized in Lockwood and Frohlich's paper, which is debunked here in a cached article that I have downloaded in case it disappears)
Datasets & Images (main page for NASA temperature data: U.S., northern hemisphere, various latitude bands, an global)
Falsification of the Atmospheric CO2 Greenhouse Effects within the Frame of Physics (in which two scientists explain that the so-called greenhouse effect violates the laws of physics)
Greenie Watch (a blog by John Ray in which he reprints articles debunking "warmism" and other enviro-nut causes)
Global Warming's Silver Lining
Heat Capacity, Time Constant, and Sensitivity of Earth's Climate System (a downward re-estimate of the likely change in Earth's temperature, summarized here by John Ray)
Heretical Thoughts about Science and Society (an essay by noted physicist Freeman Dyson, in which he factually and logically dissects global-warming alarmism)
The Iris Opens Again? (a post about research into the cyclical relationship between clouds, warming, and cooling)
Let's Be Honest about the Real Consensus
Let's Look on the Sunny Side (Timesonline article about the sun and global warming)
M&M Project Page (summaries of and links to scientific analyses that refute the "hockey stick" paradigm upon which the global-warming scare rests)
New Peer-Reviewed Scientific Studies Chill Global Warming Fears (annotated bibliography, released by the ranking minority member of the U.S. Senate Committee on Environment and Public Works)
Peter Huber And Mark Mills On Our Energy Future
The Real Deal? (introductory article about cosmoclimatology, with links to 10 other articles on various aspects of "warmism")
A Report from the Global Warming Battlefield
Scientific Forecasts vs. Forecasts by Scientists (documentation of the fact that the climate models that support "warmism" based on opinion, not evidence)
Tellus More about Hurricanes (a post at World Climate Report about three journal articles on the relationship between "global warming" and hurricanes)
Trouble in Climate-Model Paradise (how climate models used to project warming trends significantly underestimate precipitation)