Natural Climate Change has been Hiding in Plain Sight

See refined assessment with evidence (thermalization) that CO2 has no significant effect on climate at http://globalclimatedrivers2.blogspot.com  (rev 10/23/16)

 Summary

About 41.8% of reported average global temperature change results from natural ocean surface temperature oscillation and 58.2% results from change in the rate that the planet radiates energy to outer space and/or reflects it, as calculated using a proxy, which is the time-integral of sunspot numbers. Using just these two factors explains average global temperatures (least biased values based on HadCRUT4 and other credible measurements) since before 1900 with 89.82% accuracy (R²=0.8982). [See revised attributions] (rev 8/3/19)

If atmospheric carbon dioxide (CO₂) is included in the calculation, it might account for as much as 17.6% of reported average global temperature (AGT) change during the period 1909-2005. If CO₂ has that much influence, then the calculated ocean surface temperature effect decreases to about 37.8% and sunspot influence decreases to about 44.6%, but accuracy increases an insignificant amount to 90.06%. This miniscule increase in accuracy indicates that CO₂ change probably has substantially less than 17.6% influence on average global temperature change.

Ocean oscillations

Some ocean cycles have been named according to the particular area of the oceans where they occur. Names such as PDO (Pacific Decadal Oscillation), ENSO (el Nino Southern Oscillation), and AMO (Atlantic Multidecadal Oscillation) might be familiar. They report the temperature of the water surface while the average temperature of the bulk water that is participating in the oscillation can not significantly change so quickly because of its high thermal capacitance ⁵.

This high thermal capacitance absolutely prohibits the reported rapid (year-to-year) AGT fluctuations as a result of any credible forcing. According to one assessment ⁵, the time constant is about 5 years. A possible explanation is that the reported rapid fluctuations may be stochastic artifacts of the process that has been used to determine AGT. A simple calculation shows the standard deviation of the reported annual average measurements to be about ±0.1 °K with respect to the trend. The temperature fluctuations of the bulk volume near the surface of the planet are more closely represented by the fluctuations in the trend. The trend is a better indicator of the change in global energy; which is the difference between energy received that is above or below break-even and energy radiated above or below break-even.

There is some average surface temperature oscillation that accounts for all of the oceans considered together of which the named oscillations are participants. Studies ^1,2,3,4 of the primary contributor (the PDO) to this planet-wide oscillation have been done which identify the period of this oscillation to be in the range of 50-70 years. One of these studies considered data from as far back as 1000 years.

Complex phase relations between the various local cycles cause the effective over-all oscillation to vary in magnitude and period over the centuries. In the present assessment, the period of the planet-wide oscillation, since before 1900, has been found to be about 64 years with a magnitude of about ± 1/5 °K. The most recent calculated trend peak was in 2005.

Sunspot number time-integral

Sunspots have been suspected as being associated with climate change for a long time. Sunspot numbers are recorded as solar cycles which have been considered by others for magnitude or for time factors with poor success when trying to correlate with AGT trends.

A low but broad solar cycle may have just as much cumulative influence on AGT as a high but brief one. Both magnitude and duration are accounted for by using the time-integral of sunspot numbers. The temperature trend rise from the Little Ice Age and over half of the AGT rise of the 20^th century are accounted for by the time-integral of sunspot numbers with an appropriate proxy factor. Of course, the time-integral of increase above or below break-even must be reduced by the time-integral of energy radiated from the planet above or below break-even; which varies with the fourth power of its absolute temperature.

The first law of thermodynamics, conservation of energy, is applied to evaluate the hypothesis that the temperature trend is influenced by sunspot numbers. Average global temperature has not changed much over the centuries so on average, over the centuries, energy-in equals energy-out. In any one year, the energy-in is given by

E_in = B * S(i)               (a)

where ‘B’ is the proxy factor. If the AGT never changed, the energy-out is given by

E_{const AGT} = B * S_avg

To account for the yearly variation in energy-out it is multiplied by the fourth power of the temperature ratio which gives

E_{i out} = B * S_avg * [T(i)/T_avg]⁴                (b)

Subtracting (b) from (a) results in the energy change for any year. Also, factor out B

E_chg = B * {S(i) – S_avg * [T(i)/T_avg]⁴}               (c)

Dividing the energy change by the thermal capacitance gives the temperature change from the previous year. Summation of changes for previous years obtains the total change from the start of the summation.

T_chng = B/C_effective * Σ^y_initial {S(i) – S_avg * [T(i)/T_avg]⁴}                        (d)

With appropriate offset this becomes the sunspot number contribution to the temperature anomaly. The high coefficient of correlation demonstrates that the hypothesis is true.

Atmospheric carbon dioxide

Atmospheric CO₂ is called a greenhouse gas (ghg) because it absorbs electromagnetic radiation (EMR) within the range of significant Stephan-Boltzmann (black body) radiation from the planet. The EMR that CO₂ absorbs (and emits) is only over a very narrow band of the over-all radiation spectrum from the planet (never mind that the ghg effect is an insignificant factor in how greenhouses work). Most of the EMR that is absorbed is emitted (nearly all of the absorption and emission is actually by water vapor) but about 11.59% is thermalized ⁸ and appears as sensible heat which warms the atmosphere.

Added increments of CO₂ and other ghgs exhibit a logarithmic decline in their influence on AGT. This is accounted for mathematically for each year by taking the logarithm of the ratio of the average CO₂ level for the year to the CO₂ level in 1895, which was 294.8 ppmv (Law Dome ⁷). The cumulative effect to a year of interest is the summation of the effects for prior years plus the effect for the current year. The best current source for atmospheric carbon dioxide level ⁶ is Mauna Loa, Hawaii.

Combined equation

The net effect on AGT of the combination of the above three contributing factors is obtained by their sum. The word equation is: anomaly = ocean oscillation effect + net sunspot & thermal radiation effect + CO₂ effect + offset. This is expressed in the following physics-based equation. 

      (1)

Where:

anom(y) = calculated average global temperature anomaly in year y, in K degrees.

(A,y) = Effective Sea Surface Temperature Anomaly (ESSTA) in year y calculated using a range (peak-to-peak magnitude) of A, °K, and the number of years since the last maximum or minimum. ESSTA is a simple (saw-tooth) surface temperature approximation of the net effect of the Pacific Decadal Oscillation (PDO) and all of the other natural ocean oscillations, named or not. It has a maximum amplitude of about ± 1/5 °K with no intrinsic energy change for the bulk volume at any time between the beginning value and the end value of its estimated 64 year period. The most recent peak was in 2005.

s(i) = average daily Brussels International sunspot number in year i

17 = effective thermal capacitance ⁵, W Yr m^-2 K^-1

43.97 = average sunspot number for 1850-1940.

286.8 = global mean surface temperature for 1850-1940, °K.

T(i) = average global absolute temperature of year i, °K,

ppm co2(i) = ppmv CO₂ in year i

294.8 = ppmv atmospheric CO₂ in 1895

B is a proxy factor in the function that accounts for the solar radiation, W yr m^-2.

C is a multiplier in the function that accounts for the influence of atmospheric CO₂, W yr m^-2

D is merely an offset that shifts the calculated trajectory vertically, without changing its shape, to center it over the measurements, K degrees. This offset is equivalent to having selected slightly different reference temperatures for the measured anomalies.

A, B, C, and D are calibration coefficients which have been determined to maximize the coefficient of determination, R² (which makes the least biased fit of the trajectory, that is calculated using the physics-based equation, to measurements). Some have mistakenly interpreted these coefficients to indicate mathematical curve fitting, which is something that is entirely different. Instead, the coefficients allow the rational estimation of the amount that each of the two or three major contributors has made to the total temperature change.

It is worth emphasizing that equation (1) provides for a test to determine the influence, or lack thereof, of CO₂ to the total contributions to global anomalies by forcing the coefficient, C, to zero and adjusting the other coefficients to maximize R².

In Figure 1, the anomaly trajectory calculated using Equation (1) is co-plotted with measurements. The excellent match of the up and down trends since before 1900 is displayed and corroborates the usefulness and validity of Equation (1).

Figure 1: Measured average global temperature anomalies with calculated prior and projected trends.

Projections until 2020 use the expected sunspot number trend for the remainder of solar cycle 24 as provided ⁹ by NASA. After 2020 the limiting cases are either assuming sunspots like from 1925 to 1941 or for the case of no sunspots which is similar to the Maunder Minimum.

The influence of CO₂ can be removed from the equation by setting C to zero. Doing so results in an insignificantly lower coefficient of determination (R²). The coefficients in Equation (1) and resulting R² are presented in Table 1.

Ocean oscillation, A	Sunspot integral, B	Carbon dioxide influence, C	Offset, D	Accuracy, R2
0.3593	0.003731	0.3112	–0.3903	0.900641
0.400	0.004894	0.0	–0.3892	0.898220

Table 1. Coefficients in Equation (1) and resulting accuracy.

The graph for zero CO₂ influence is not significantly different through 2005. After 2005 the slope is slightly steeper resulting in a projected temperature trend approximately 0.12 K cooler in 2020.

Complementary theories as to why this calculation works have been described previously¹⁰. The most significant theory appears to be: Fewer sunspots; reduced solar magnetic shielding; increased galactic cosmic rays penetrating the atmosphere; increased low-level clouds; lower average cloud altitude; higher average cloud temperature; increased cloud-to-space radiation; declining AGT.

It is easy to show that an increase in average cloud altitude of about 100 meters would account for half of the AGT increase in the 20^th century that some have referred to as ‘Global Warming’. Increased low level clouds also means increased over-all cloud cover with attendant increased albedo. This also leads to declining AGT ¹¹.

Without human caused Global Warming there can be no human caused climate change.

Climate science appears to have missed the above and other factors ¹².

Corroboration that CO₂ is not a significant forcing  (added 2/10/15)

It is trivially easy for anyone with access to existing CO₂ and temperature measurement data-sets to falsify the statement that CO₂ (at any level that ever existed) causes significant warming.

If CO₂ is a forcing, a scale factor times average CO₂ level times the duration divided by the effective thermal capacitance (consistent units) equals the temperature change of the duration. Thus the temperature responds gradually to a forcing. During previous glaciations and interglacials (as so dramatically displayed in An Inconvenient Truth) CO₂ and temperature went up and down nearly together. This is impossible if CO2 is a significant forcing so this actually proves CO₂ CHANGE DOES NOT CAUSE SIGNIFICANT CLIMATE CHANGE.

See more on this and discover the two factors that do cause climate change (95% correlation since before 1900) at http://agwunveiled.blogspot.com . The two factors which explain the last 300+ years of climate change are also identified in a peer reviewed paper published in Energy and Environment, vol. 25, No. 8, 1455-1471.

Conclusions

This assessment demonstrates that the annual average temperatures of the planet, for at least as far back in time as accurate temperatures have been measured world wide, are accurately calculated by considering only natural ocean oscillations and the sunspot numbers, and that credible changes to the levels of non-condensing greenhouse gases have no significant influence on average global temperature.

Equation (1) explains approximately 90% of the AGT trajectory since before 1900. All factors that were not explicitly considered must find room in the unexplained 10%.

References:

1. MacDonald, Glen M. and Roslyn A. Case (2005), Variations in the Pacific Decadal Oscillation over the past millennium, Geophysical Research Letters, 32, L08703
2. Mantua, N. J., S. R. Hare, Y. Zhang, J. M. Wallace, and R. C. Francis, A Pacific interdecadal climate oscillation with impacts on salmon production. Bull. Am. Met. Soc. 76, 1069-1079, 1997
3. Minobe, S., (1999), Resonance in bidecadal and pentadecadal climate oscillations over the North Pacific: Role in climatic regime shifts, Geophys. Res. Lett., 26, 855–858.
4. Minobe S., (1997) A 50–70 year climatic oscillation over the North Pacific and North America. Geophs. Res. Lett., 24, 683–686.
5. Schwartz, Stephen E., (2007) Heat capacity, time constant, and sensitivity of earth’s climate system, J. Geophys. Res., vol. 113, Issue D15102, doi:10.1029/2007JD009373
6. Annual average atmospheric carbon dioxide level at Mauna Loa ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_annmean_mlo.txt

     7.      Atmospheric CO₂ level measured in Law Dome, Antarctica ice cores   http://cdiac.ornl.gov/ftp/trends/co2/lawdome.combined.dat

8. http://climaterealists.com/attachments/ftp/Cloudaltitudevsglobaltemperature.pdf
9. Graphical sunspot number prediction for the remainder of solar cycle 24 http://solarscience.msfc.nasa.gov/predict.shtml
10. http://climaterealists.com/attachments/ftp/Verification%20Dan%20P.pdf
11. http://endofgw.blogspot.com/
12. http://consensusmistakes.blogspot.com/

Obsolete graph