The main reason for the existence of climatic regions on our planet is the tilting of the Earth's vertical axes and the elliptic rotation of the Earth around the sun. This causes the amount of incoming solar radiation to vary throughout a year. As a result we have four seasons each lasting around 90 days.
As said, the orbit of the Earth around the sun is not a perfect circle, this too is causing variations in the seasons and weather. It is more like an elliptical and during January the Earth is closest to the sun (perihelion). And even this ellipse is also not stable causing more changes in the incoming solar radiation (insolation).
Excerpt from the document:
In 2001, the United Nation’s Intergovernmental Panel on Climate Change (IPCC) announced that carbon dioxide (CO2) was causing the Earth to warm and developed computer models to predict how much the Earth would warm in the future. Does any empirical scientific evidence exist to support this premise of the IPCC? The answer is no, in fact it is just the opposite, CO2 has a cooling effect.
The major components in the atmosphere that cause the Earth to be cooler than it would be otherwise are the so-called greenhouse gases. Calling these gases greenhouse gases are misnomers. Yet, many meteorologists have blamed water vapor and carbon dioxide in the atmosphere for warming the Earth.
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