If the degree of the Earth’s tilt were to be modified for some reason or another, the changes we would see would be as drastic as the Earth’s tilt was.
Even though our Earth is approximately 4.5 billion years old, its characteristics have not changed much in terms of its axis of rotation and movements around the Sun. Although in recent decades, the tilt axis of our planet has been changing due to anthropogenic activities, so we wonder what would happen if the Earth were to go off its axis; what would be the consequences?
The Earth’s Rotation Axis
All planets are special and have unique characteristics; in the case of the Earth, it has an angle of inclination of 23.5º concerning the perpendicular. To understand this, imagine the Solar System and draw an imaginary horizontal line, this should cut in half the Sun and all the planets; it would also be the orbit of translation of these. This line is known as the ecliptic.
Now that you have a horizontal base, imagine a line 90º concerning the ecliptic; this should be the axis of rotation of the Earth if it were perfectly vertical, but as we have seen it is not. From the perpendicular, the Earth is slightly tilted at 23.5º. This is why we have the movement known as the precession of the equinoxes, which is responsible for the equinoxes and solstices, as well as the change of seasons.
What Would Happen if the Earth Were to Go off its Axis?
If the degree of the Earth’s tilt were to be modified for some reason or another, the changes we would see would be as drastic as the Earth’s tilt was. For example, if the axis were to fall completely on the ecliptic, the northern hemisphere would be fully exposed to the Sun’s rays, and the southern hemisphere would be in shadow for months at a time.
This would of course have consequences for planetary dynamics in every sense, starting with a near doubling of temperatures in the north that would affect local ecosystems. The Arctic would eventually melt, releasing a large number of gases trapped in the permafrost, and the northern glaciers and ice shelves would be reduced to their liquid state, entering an enormous amount of water into the oceans. Sea levels would be affected and rise by a whopping 7 meters so that many of the world’s coastal cities would end up under the sea.
But the water inflow would not be the only thing, because with a much higher temperature the atmospheric dynamics would also change. In the south, the situation would be diametrically opposed, with a region plunged in cold and darkness. But it would suffer the same fate as the north, and, likely, most of the species that inhabit these regions would simply be gone. Humans would have to move and concentrate in more equatorial areas; however, overpopulation would undoubtedly be an impediment for everyone to continue to boast a moderately bearable quality of life.
How Much Has the Earth’s Axis Changed?
From data from the Gravity Recovery and Climate Experiment (GRACE), a joint mission between NASA and the German Aerospace Center, researchers were able to obtain data on the distribution of mass around the planet, measuring unequal changes in gravity at different points, which means that there have been changes in the distribution of water, as there has apparently been a loss of water masses at the poles, which would be the main cause of variation in the Earth’s tilt axis.
It is known that throughout the life of the planet Earth, there have been variations in its axis, although none so important as to cause chaos. However, this is the first time that the Earth has altered one of its variables as a consequence of anthropogenic activities such as global warming, which is redistributing water in different ways and evidently affecting the planet’s center of gravity.
Story originally published in Spanish in Ecoosfera