The huge difference is, one group believes in AGW (Anthropogenic Global Warming) as a religionthat man can, and is, controlling the warming of earth with excess CO2. Another group believes in Natural Cyclesthat man is totally dependent on the myriads of astrophysical cycles that are engineered to occur naturally.
One group does not consider themselves omnipotent enough to control a planets climate, are cognizant of the hundreds of cyclical changes the earth goes through.
Back in 950 AD, Eric Thorvalssen (better known as Eric the Red) was born a Viking, in Norway. After exile, he convinced many to visit his personal islandaccurately called Greenland. For the next 300 years, Greenland became a whaling, fishing, and farming community coinciding with the MWP (Medieval Warming Period). But now, numerous sites in Greenland have been uncovered, suggesting temperatures were as much as 7oF warmer than today (F. Donald Logan/ The Vikings In History). Today most of Greenland is not green, and has permanently frozen soil and ice.
A major factor effecting earths climate is earth-sun geometry. Milutin Milankovitch gets most of the credit for relating the Milankovitch cycles to ice ages and to climate. Its three cycles: 1) Precession (earth rotates on its polar axis, and wobbles [26,000 years]); 2) Eccentricity (when earth’s orbit around the sun[100,000 years] is at its maximum distance(9%), the difference in solar energy received by earth is (-20%)); and 3) Axial Tilt/Obliquity [41,000 years], all provide variations in solar radiation received.
Milankovitch cycles exert their greatest influence when the troughs and peaks of all three cycles coincide with each other. But with sunspot activity, everything gets expanded.
With a cycle time of 2241 yrs, the Landsheidt cycle resulted in earth’s cooling in 1400 AD; with a cycle time of 208 yrs, the Suess cycle cooled in 1898 AD; with cycle time of 232 yrs, a conglomeration of several cycles cooled the earth in 1922 AD; and with a cycle time of 88 years, the Gleissburg cycle cooled in 1986 AD.
Solar output is a major factor affecting earths climate. Other climate changers are interstellar dust, atmospheric chemistry, surface/cloud reflectivity, and atmosphere/ocean heat exchange. To a smaller extent El Nino, La Nina, continental drift, volcanic eruptions, and mountain-building also affect climate.
Known cycles always exist: TSI (Total Solar Irradiance), PDO (Pacific Decadal Oscillation), and AMO (Atlantic Multidecadal Oscillation). More importantly, we see sunspot variation ranging from the Schwabe Cycle[11 yrs], Hale[~22 years], Gleissburg[70-100 yrs], Suess[~210 yrs], Halstatt and Landsheidt[~2300 years], and Xapsos[~6000 yrs].
Some of the more famous climate changes were: the Damon Minima (1880-1930 AD), temperature 0.5 oC lower [Jones, 1988]; the Dalton Minima (1795-1825 AD), “Year Without Summer (1813 AD); the Maunder Minima (1650-1710 AD), resulted in the Little Ice Age, global temperature 1-2 oC lower; the Sporer Minima (1420-1540 AD), resulted in Second Little Ice Age; and the Wolf Minima (1280-1340 AD), resulted in The Great Drought.
The Maunder Minimum is a prime example of solar cycles seriously affecting earths climate. Almost no sunspots were seen from 1645 to 1715. During this time, regional climates had episodes of unnaturally cold weather.
Based on evidence from sunspot counts, there have been 18 periods of sunspot minima in the last 8,000 years. Studies indicate the sun currently spends up to a quarter of its time in these minima. The lack of sunspots means elevated cosmic rays, which means additional cloud formation, resulting in possible reflection of 20% of the sun’s rays, therefore earth cooling.
However, the Solar Variation in emissions of high energy X-rays and UV radiation is far more dramatic over the course of a sunspot cycle. UV emissions increase by factors of 2-10, while some X-ray emissions increase over a hundred-fold with differences in sunspot activity.
Gassers continually point out CO2 is THE culprit for AGW. But its known CO2 was much higher in the past. There was an explosion of life forms in the Cambrian Period when CO2 levels were 18x higher than today, and in the Jurassic period (when dinosaurs roamed) CO2 levels were as much as 9x higher.
So many AGW believers point to Michael Manns debunked Hockey Stick temperature graph (IPCC Technical Summary 2001, p 29). Mann included temperatures from major cities that had huge artificially-induced upward swings due to heat-trapping influences of concrete, asphalt, and steel (Urban Heat Island effect). Somehow, Mann excluded highly accurate temperatures taken by satellites.
When accurate data was collected, only a miniscule warming was present since 1979. McIntire & McKitrick (Corrections to the Mann [The M&M Critique update]) noticed a variety of errors disintegrating Manns blade on the hockey stick. UN IPCC scientist Eduardo Zorita publicly declared Climategate colleagues Michael Mann and Phil Jones “should be barred from the IPCC process…They are not credible anymore.”
More and more scientists are speaking out about AGW [For the Full Report in PDF Form, please click here.] Back in 8/09, over 700 scientists dissented with the UN on AGW. Now, over 1,000 dissenting scientists are almost 20 times the number of UN scientists (52) who authored the media-hyped IPCC 2007 Summary for Policymakers.
The Science and Public Policy Institute (SPPI) brings all the correct data together in a monthly report (For the Full Report in PDF Form, please click here.) As in The Perfect Storm, there were times in history (cited) when several of the above cycles perfectly aligned, and caused highly noticeable climate changes.
Estimating greenhouse gases affecting climate pushes a probabilities estimator close to zero. Of course, one can bring in another unseen variable that will raise the likelihood of estimation to almost one. In other words, the estimator would call that surety.
We call that variable——GOD.
Kevin Roeten can be reached at firstname.lastname@example.org.Tweet