THE REAL CONTROLS OF CLIMATE - WARMING AND COOLING
The Milankovitch CycleA few tens of millions of years ago, Earth was much warmer. The dinosaurs ruled the earth, roaming huge rain forests (as in "Jurassic Park"). Those rain forests are the source of our coal and petroleum today. The continents were near the Equator. There were no permanent ice caps on the earth, and only a few mountain glaciers, because warm ocean currents circulated freely over the poles, melting the Winter ice.
By 25 million years ago, continental drift had moved Antarctica over the South Polar cap, blocking the warm ocean currents and allowing permanent ice to accumulate there. This instituted an Ice Epoch, in which a major part of the Earth became permanently glaciated. Fortunately, Antarctica is isolated from the other continents by warm oceans. Glacial ice breaking off is rapidly melted, without forming glaciers on South America or Australia.
By 7 million years ago, the Northern Hemisphere continents had drifted into the present position around the North Polar cap, blocking warm ocean currents and allowing permanent ice to accumulate from year to year, over Greenland and on the American and Asian continents. The continents provided a path for the glaciers to move South. The grip of the Ice Epoch grew stronger. For tens of thousands of years at a time, the glaciers accumulated and moved south, covering the land with ice thousands of feet thick. Because of current continental configuration, the Earth is "normally" much colder - 20 degrees Fahrenheit colder - than present, for 90% of the time. It's the climate depicted in movies about cavemen and mammoths.
Milutin Milankovitch, a Serb mathematician, was the first to realize that the major climate question is to explain the warm Interglacials. He did so, making calculations of Earth's orbit by hand (no computers then), during the 1920's and 1930's. His results were published in 1930, and were dismissed by geologists of the time. More accurate dating of geological periods, based on radioactive decay, proved Milankovitch correct.
In the figure below, the warm "interglacial" periods, every 100,000 years or so, make human civilization possible. The figure illustrates the Milankovitch Cycle. The Milankovitch Cycle features long 90,000 year Glacial periods, interrupted briefly by short, 10,000 year Interglacials.
Strangely, a graph like this appears in "An Inconvenient Truth" (AIT). The important information it contains - that most of the last several hundred thousand years have been glacially cold - is never mentioned. The fact that warm Interglacials are short, and that ours is nearing its end, is never mentioned. AIT completely perverts the truth about long-term climate change.
Additionally, temperature changes before carbon dioxide. This is a general relationship between carbon dioxide and temperature, as seen in data from many ice core samples - the change in temperature LEADS the change in carbon dioxide by several hundred years. (Ice core samples include trapped bubbles of air, which allow measurement of carbon dioxide content and an estimate of temperature, through comparison of relative amounts of oxygen isotopes.) Since the change of temperature happens before the carbon dioxide concentration changes, this makes nonsense of the claim that carbon dioxide causes temperature change. AIT is careful not to mention the time difference between the two variables. Here's what section 6.4.1 ("Paleoclimate") of the Working Group 1 Report of the IPCC says:
“The ice core record indicates that greenhouse gases co-varied with antarctic temperatures over glacial-intergalcial cycles, suggesting a close link between natural atmospheric greenhouse gas variations and temperature (Box 6.2). Variations in CO2 over the last 420 kyr broadly followed antarctic temperature, typically by several centuries to a millennium (Mudelsee, 2001). The sequence of climatic forcings and responses during deglaciations (transitions from full glacial conditions to warm interglacials) are well documented. High-resolution ice core records of temperature proxies and CO2 during deglaciation indicates that antarctic temperature starts to rise several hundred years before CO2 (Monnin et al, 2001; Caillon et al, 2003).” [emphasis added]
A warm Interglacial requires maximum heating of the North Polar region during Summer, in order to melt the accumulated Winter snow and ice. The necessary astronomical conditions occur only at 100,000 year intervals. Our present interglacial is due to the coincidence of Northern Hemisphere Summer (when the North Polar region is in sunlight) with earth's closest approach to the Sun (i.e., perihelion). It's also important to have maximum eccentricity of Earth's orbit, and a high inclination of Earth's spin axis. Those conditions were optimum about 20,000 years ago, melting - for a while - the Glacial Ice. Since then, the situation has reversed; we now have Northern Hemisphere Summer (June 21) closely coincident with farthest distance from the Sun (July 3). We are living on borrowed time. The average Interglacial lasts 11,000 years; we're 1,500 years overdue. That's why the unexplained cold climate from 1940 to 1977 had climatologists concerned that a Glacial Age was returning. Inevitably, it will - perhaps in a thousand years, perhaps a hundred, perhaps less. When it does, the glaciers will begin to crowd humanity toward the Tropics - where homo sapiens originated 150,000 years ago.
On a shorter time scale of decades, there is a theory (one of several), the Pacific Decadal Oscillation (PDO), that tells us storms and cold weather should be expected in the coming climate, the next 20 to 30 years. The Pacific Decadal Oscillation was identified at the University of Washington in 1996. The theory postulates - based on observational data - that the Pacific Ocean, Earth's largest, goes through shifting phases of warm and cold in East and West. From a selfish point of view, we in the US are warmed by a warm phase, and chilled by a cold phase. The climate models of the Intergovernmental Panel on Climate Change don't include the PDO.
As we see from the diagram on the right, there was a warm phase from 1915 to 1945, which included the "Dust Bowl" years, the warmest period in American climate. From 1945 to 1977, the PDO was in its cool phase, and climatologists - and The Media - considered a returning Ice Age. (TIME magazine had a cover story in July 1974 about the coming doom.) Fortunately, Doom was averted when the PDO entered a new warm phase in 1977, when many climatologists noted a Great Pacific Climate Shift. This warm phase of the PDO lasted until 1998, culminating in the major El Nino of 1997 - 1998 (hyped by Mr. Gore as "the warmest year of the Millenium.") PDO phases typically last about 30 years.
Following 1998, the PDO appears to have gone back into its cool phase. What does this mean? Normal circulation in the Pacific includes an equatorial transport of water westward, due to the prevailing Trade Winds. The water transported westward is replaced by cold water, upwelling from lower depths along the coast of South America. Similar cold upwelling takes place along the California Coast, leading to Twain's famous remark that "the coldest Winter I ever spent was a Summer in San Francisco." This pattern of strong equatorial westward flow is referred to as "La Nina." During La Nina conditions, warm water "piles up" around Indonesia and Australia; sea level there may be two feet higher than along the South American Coast.
Occasionally, for reasons we don't yet understand, the Trades weaken, or cease altogether, the westward current halts, and warm water flows back Eastward. The cold upwelling along the coast is replaced by warm water. The warm water off the west coasts of the Americas provides an energy source (evaporation) for developing storms; the most famous such episode was in the extended El Nino of 1997 - 1998, when storms battered the California Coast and the Santa Monica pier was destroyed. In South America, El Nino reduces or eliminates fishing, since the fish follow the nutrient in the cold upwelling water. No upwelling, no fish.
What was recognized only recently is that El Ninos are stronger, and more frequent, during the warm phase of the PDO; La Ninas dominate during the cold phase. An example is the 1945 - 1977 cold phase, when The Media warned us of a coming ice age. On the figure, that 1945 - 1977 cold phase has been extrapolated to our own time. Both the University of Washington and NASA/JPL agree that the PDO has entered its warm phase, with more cold La Ninas to be expected. Cooling temperatures and increased snowfall may be the dominant climate for the next generation.
Climate change and solar activity
Another hypothesis of short term (decades) climate change is obvious (but not considered by the IPCC). Our sun is a variable star; we have records of its variability, manifested in the number of sunspots visible through a telescope (developed by Galileo in the early 1600's).
A recent hypothesis put forward by Svensmark and Calder ("The Chilling Stars", 2007) suggests that a strong solar magnetic field shields the earth (which it surrounds) from high-energy Galactic Cosmic Rays (GCRs). The GCRs, presumed to come from supernovae far outside our Solar system, have enough energy to create ions in Earth's atmosphere. These ions act as nuclei for the formation of cloud droplets in the lower atmosphere, which cool the earth. Thus (it is hypothesized), an active Sun warms the Earth, not by increased Total Solar Irradiance (TSI), but by shielding it from GCRs. Likewise, a weak Sun permits more GCRs to penetrate, creating more clouds and cooling. Archaeologists are aware of this effect as well, since the increase (and decrease) of GCRs and ionization leads to more (or less) Carbon-14, used for dating organic material from the past - fabric, wood, human tissue, etc. Experiments are underway at CERN to test this hypothesis. Incidentally, this hypothesis explains the long-term cooling of Antarctica, even during the worldwide warming since 1977, as the CO2 warming hypothesis does not. That explanation is too long to repeat here.
It's well known that there was an extended minimum of sunspots from 1645 through 1715, known as "The Maunder Minimum." Climatologists have noted that the Maunder Minimum coincides with the coldest part of "The Little Ice Age" (LIA). As described in the book of the same name by Brian Fagan (see the References), crops failed, the Norsemen withdrew from Greenland, English viniculture ended, transportation became more difficult, and the Seine and Thames Rivers and the Dutch canals froze in the winters. The Indian civilizations of Kahokia (Illinois) and Chaco Canyon ended. Every cloud has some silver lining; Antonio Stradavari found the spruce wood of the time so hard and dense - it grew very slowly - that it had a resonance that was perfect for his violins.
Probably not a coincidence - especially since it happened again in The Dalton Mimimum, 1790 - 1820. That period of minimum solar activity - sunspots - includes the terrible retreat of Napoleon's army from Moscow in 1812.
There's an interesting contrast here with the UN-fostered CO2 theory of AGW. The hypothesis of solar control of climate change is based on observed data; it's inductive. On the other hand, the CO2 theory is deductive; it's a theory in search of some supporting data. Such an approach is very susceptible to "cherry-picking", that is, choosing only the data that supports the hypothesis, and ignoring the contrary. An example is the cool period from 1945 through 1977, when CO2 was increasing in the postwar boom, and temperature was decreasing. In the 1970's, we heard a great deal from climatologists and the Media about a coming Ice Age. The anti-correlation is one of the internal contradictions of the assertion of AGW by CO2.
Is there a more recent example of decreased solar activity and correlated colder temperatures? Yes. In the early years of the 20th Century, 1912 - 1913, there was a similar period of minimal solar activity.
Here are the ranks of the years, out of 114 years: 1911(#65), 1912 (#2), 1913 (#32), 1914 (#47), 1915 (#22), 1916 (#6), 1917 (#1), 1918 (#49), 1919 (#25), 1920 (#9). 1911 was an average year; all the rest were below average, with the average rank of the decade at #26 - the coldest decade in the 20th Century. Note there was a decade of cold, not just during the years of less sunspots. Incidentally, 1910 and 1917 are also the two driest years in American climate history - yes, drier than the Dust Bowl years. In Colorado, except for 1910 and 1917, all years of the decade were wetter/snowier than average. The Colorado River Compact, allocating Colorado River water among the various states, was signed in 1922, rather unrealistically. Because of the preceeding wet period, the Compact allocates more water than is normally available. The reader can find climatological data online at the National Climatological Data Center.
So, a period of few or no sunspots seems to be followed by several years of colder, wetter climate. Now we're in a period of few or no sunspots. AGW theory, based on CO2, predicts warmer and drier years ahead. A prominent CU faculty member, Prof Mark Williams of the Geography Dept, recently (Dec 2008) completed a study for the Aspen Ski Institute, predicting disaster due to warming (10.4 C) and decreasing precipitation - so much that the lifts would have to be moved up the mountain. Prof Williams' prediction came out (and was dutifully reported by Bill Scanlon of the Rocky) as Aspen and all Colorado resorts were reporting record December snow.
Man, you wimpy Americans are nothing like us Norsemen. I'm kind of ashamed of you - since, in a sense, I 
Sunspots, which show up as dark patches on the surface, are indicators of increased solar output of radiance, of mass (the solar wind), and of a stronger solar magnetic field. As illustrated on the right, we're in a period (2007-2008-2009) of few or no sunspots.
There is an interesting theory for the variation of solar activity, due to disturbances of the Sun's angular momentum by the giant planets (Jupiter, Saturn, Uranus, Neptune), formulated by the solar physicist Landscheidt , which is too long to repeat here. However, Landscheidt predicts a long-term cooling between now (2009) and 2030, with minimum temperatures comparable to those of The Little Ice Age. Landscheidt definitely doesn't accept the IPCC theory of AGW.
The number of sunspots in those years is plotted above; the US annual temperature is plotted at left. 1911 had 200 spotless days; 1912 had 253 days without spots; 1913 - the champ in modern times - had 311 spotless days. Now we have gone 266 spotless days in 2008, preceeded by 163 in 2007. Was the previous period of few sunspots a cold one? Yes!
was the First American. We Norse found this continent a thousand years ago. Now you're letting Socialist politicians - like the ones I left behind in Europe - take it away from you. Lucky Leif
Rev. Feb 09