As part of the TV series called “Two degrees”, that usually has themes related to weather science, one of the followers addressed the moderators with an interesting issue. It would seem that climate changes are linked to natural cycles, and that human interference plays a very small role in this grand play.
The viewer’ question was more on the lines of natural occurrences versus human involement in current weather changes. He said that, throughout its long natural history, Earth was hit numerous times by ice age. Moreover, this ice ages occurred in a time before man hasn’t even stepped out of the primordial soup. So, who is the winner of this completion? Human kind or Mother Nature?
The answer is much more complicated that it would initially seem, but it all boils down to one fact: nature has its way. It seems that, during extended period of time, ranging from a few thousands to several million years, Earth undergoes a series of weather shifts.
Typically, after a depressing ice age, Earth shifts to a friendlier interglacial period. This post-ice age period is characterized by increase temperature, melting ice caps and a significant increase in sea water levels.
These periods of oscillations between warm and cold are part of a weather predicting system called the Milankovitch cycles. Named after the celebrated geophysicist and astronomer Milutin Milankovitch, the system is a mathematical model used to predict how Earth’s movement can affect the planet’s climate.
According to the mathematical model, any variations regarding Earth’s eccentricity (calculates a planet’s deviation from its circular orbit), axial tilt and precession can impact Earth’s weather patterns. The phenomenon by which Earth’s weather undergoes severe changes due to changing astronomical parameters is called orbital forcing.
Astronomical measurement state that Earth’s axis undergoes a full precession every 26.000 years. While the axis rotates so does its elliptical orbit, albeit that the rotation rate is much slower. Combining the two rotational velocities, we are looking at a shift in weather patterns every 21000 years.
So climate changes are linked to natural cycles occurring once every 100000 years. Well, even though Earth undergoes serious maintenance in weather distribution, the overall temperature variance seems to be rather insignificant. According to meteorological measurement, since the end of the 19th century, Earth’s temperature has increased only by 0.85 degrees Celsius.
In conclusion, the numbers and weather facts show us that man had little to do with the weather changes. Even though the burning of fossil fuels that led to the buildup of carbon dioxide in our atmosphere dates back to the early years of the Industrial Revolution, the impact on Mother Nature is rather marginal. Mother Nature has its way of dealing with things in due time.