So, in regards to my last article posted many of you may be wondering exactly how I came upon these conclusions. For every statement in science there has to be significant proof to back it. So this post is my summary article that I wrote for this study. This article provides the basics of the entire research. I have tried to keep it as simple as possible, however if you have any questions, I would be delighted to answer! This is been over a year in the workings, so I hope it provides a sound agreement in regards to human induced global warming.

Milankovitch theory was created by Milutin Milankovitch a Serbian geophysicist and astronomer during the First World War. Milankovitch theorized using mathematics that variations in three of the planetary motion of the earth: the eccentricity of the orbit, axial tilt, and axial precession had a profound effect on the solar radiation and insolation affecting the climate of the earth.  These three motions occur in regular cycles. The axial precession, change in orientation of earth?s rotational axis, cycles every 26,000 years. Earth?s axial tilt, the tit of the axis (known as obliquity) varies between 22.1-24.5 degrees occurs every 41,000 years. Eccentricity cycle or change in the shape of earth?s orbit occurs in periods of 100,000 years. The purpose of this project is to find the definitive effects of these three cycles upon the global temperatures.

I set up 2 targeted experiments and 2 data based analysis to achieve my goal.

For the first experiment I targeted on finding the relation between a decreasing phase of eccentricity and the overall climate of the earth along the 4 major events along the earth?s orbit: perihelion, aphelion, and the two equinoxes. I generated 3 model ?orbits? for my globe to follow around the heat lamp with varying eccentricities calculated by using the formula e=f/v since eccentricity was the ratio of distance from centre to focus (focal length-f) over distance from focus to vertex (vertex length-v). Temperatures were taken at 4 points for each model orbit. Studying the patterns I found in my experiment I could make a general relation that as the eccentricity decreases, the temperatures at perihelion decrease, but there also an increase at aphelion and steady increases at both equinoxes. This will cause a seasonal hemispheric change and create more balanced and equal seasonal climate for both hemispheres.

My next experiment focussed on drawing a relation between a decreasing axial tilt and the hemispheric effects on the climates. I used objects of varying heights to both increase and decrease the axial tilt of my globe which was about 23.5? This was done by creating the angle of elevation between the base of the globe and the ground which formed a right triangle with the legs being the height of the object and the length of the ground covered and the hypotenuse to be the base of the globe. The angle of elevation could be calculated using inverse right triangle trigonometry by inverse cosine. It was added or subtracted to the original tilt of 23.5?based on which side of the incident radiation the object was placed. I took the temperature at the tropics (representing the hemispheres) and equator with each tilt manipulation. My results showed me that the latitudal temperature gradient would decrease as the tilt decreased, thus resulting in the seasons becoming less clearly defined as the tilt decreased. This created an overall global effect of cooler summers and warmer winters creating and by itself would cause an overall global cooling trend in both hemispheres.

I then researched the formula for calculating the obliquity of the ecliptic and saw a linear decrease in the values over the past century.  I compared to see if there was slight dip in the recorded temperatures in the last 160 years to see the relation was in effect in real world. I collected climate data from 2 cities: Calgary, Alberta and Melbourne, Australia carefully chosen based on hemispheres, climate zones, and other internal climatic factors.my result shows that the maximum temperatures for Calgary showed the expected dip but the Melbourne temperatures showed record high temperatures especially in the last 15 years of data collected.  Does this reveal the human accelerated global warming trend?

The last section was a research study for the axial precession and concluded that as this lowest periodicity factor continues to cycle toward its other maximum the seasonal climates will be reversed which will result in the northern hemisphere taking on the role of the southern hemispheres seasons in relation to the events along earth?s orbit. This will result in the northern hemisphere taking on the South?s warmer summers and cooler winters and vice versa for the southern hemisphere. The effects of precession depend upon the other 2 cycles. At low eccentricity and low tilt, the precession effects will be low.

So now for the final conclusion:

As the eccentricity decreases it will result in the seasonal climate between the two hemispheres becoming more balanced and equal. As the tilt decreases this will result in the seasons becoming less prevalent and the seasonal climate weakening. As these two factors decrease, it will cause a decrease in the effects of precession. At maximum tilt and eccentricity, the climatic effects of precession will be at its maximum. But, when these two factors decrease, especially eccentricity, the influence and strength of precession decreases. This is because precession causes a change how dramatic the seasons are for the hemispheres along the elliptical orbit, but as the orbit becomes more circular this effect of hemispheres having unbalanced and dramatic seasons is reduced. Overall this may result in the seasonal climate becoming weaker. But, as the seasons weaken, the climate should balance out globally and result in weaker summers and winters. This should result in a slight cooling globally.  

As the eccentricity decreases it will result in the seasonal climate between the two hemispheres becoming more balanced and equal. As the tilt decreases this will result in the seasons becoming less prevalent. As these two factors decrease, it will cause a decrease in the effects of precession. Overall this may result in the seasonal climate becoming weaker. But, as the seasons weaken, it should result in a slight cooling globally. If our recent climate data is showing contradiction to this astronomical perspective than this suggests that something has been fundamentally changed in earth?s internal environment.

Regards,

Nitish Bhatt