Water is life, it sustains life, and is a prerequisite to the existence of a living world. It is also the most important resource of, for, and on the Earth, and is integral to maintaining the natural balance.
We have water everywhere, in different forms, but how much of it is readily available at our disposal, is a pertinent question. According to the United States Geological Survey, “The Earth is a watery place. But just how much water exists on, in, and above our planet? About 71% of the Earth’s surface is water-covered, and the oceans hold about 96.5% of all the Earth’s water. Water also exists in the air as water vapour, in rivers and lakes, in icecaps and glaciers, in the ground as soil moisture and in aquifers, and even in you and your dog.”
Of the 3.5% of the world’s freshwater, only 1% is in lakes and rivers, directly available for human use. Hence, paradoxically, water becomes the single-most invaluable resource, on which our very survival depends.
Today, exploitation of this very resource is wreaking havoc. A section of historians, political scientists and researchers also go to the extent of postulating that ‘water’ would spark the next ‘World War’. According to researchers, water wars are expected in the next fifty years. But there is a bigger concern begging attention at the moment.
A change in tilt
Excessive extraction of groundwater is not only making people’s daily lives difficult, but has affected the mechanics of our planet itself. According to the latest research, excessive extraction of groundwater has tilted the Earth’s axis by 31.5 inches, i.e. around 80 cm.
A research paper – Geophysical Research Letters - Drift of Earth’s Pole Confirms Groundwater Depletion as a Significant Contributor to Global Sea Level Rise 1993-2010 – published in 2023 by a team of researchers, Ki-Weon Seo, Dongryeol Ryu, Jooyoung Eom, Taewhan Jeon, Jae-Seung Kim, Kookhyoun Youm, Kianli Chen, and Clark R Wilson, stated the findings based on climatic models and hydrological sources. The paper was again revised this year. According to the release of the paper by American Geophysical Union, Advancing Earth and Space Sciences: “Based on climate models, scientists have estimated that humans pumped 2,150 gigatons of groundwater, equivalent to more than 6 mm (0.24 inches) of sea level rise, from 1993-2010.”
In the study, the researchers point out: “The Earth’s pole has drifted by 78.48 cm to 64.16 degrees East, and a speed of 4.36 cm per year. The ice sheets and mountain glaciers melting in the polar regions has also been the cause of the rise in the mean sea level. It is also associated with climate change.”
Explaining how the tilt in the Earth’s axis will have an impact, Ki-Weon Seo, geophysicist at Seoul National University, has been quoted as stating that among climate change causes, a dip in groundwater levels and its redistribution has a major impact on the change of the rotational pole.
Interestingly, the researcher also notes in the study that the spinning of the Earth was different to the way water levels shifted. They note that as ice melts in Greenland and Antarctica, it flows towards the equator, which is altering the planet’s balance and is causing for the axis to shift.
For the study, the researchers also used terrestrial water and changes in the ice mass to study the variations in the sea level. They state: “Data shows a total groundwater variation and depletion, during the study period. There is also an impact on the oceans, where there has been a near 10-mm rise, but a sea-level drop, in the Indian and Pacific Oceans. This is in parallel to the dip in groundwater levels on land, surrounding these oceans.” The researchers also note that most of the water that was redistributed was in western North America and northwestern India. This has also now raised concerns of the water storage efforts and capacity of the underground aquifers which play a vital role in holding groundwater.
Far-reaching implications
In the findings, the research team also explains how the total groundwater storage is contributing to the global mean sea level rise and leading to the tilt in the Earth’s axis. In the paper, they explain that the total water storage also includes contributions from reservoirs, dams and soil moisture. It points out that the increasing number of dams and their water storage is increasing, which has mitigated the global mean sea level rise from the early 20th century.
“We (people) do not feel the immediate impact, but this will have large-scale implications. Details of global studies are being done on this. Tilt in the Earth’s axis has been happening gradually and it’s now visible clearly through satellite images. In the last 10-12 years, there has been a maximum dip in groundwater levels due to excessive extraction in the northern hemisphere. Due to this, there has been large-scale mass disturbances. As researchers are sharing notes on the spatial implications, the climate change impact is also being ascertained. The long-term impacts have to be studied at length, but expeditiously,” said a researcher and expert from the Indian Institute of Science (IISc), Bengaluru.
The tilt in the Earth’s axis has also caught the attention of ISRO and NASA scientists, who are now using this to study its impact on their future projects, as this would affect the timescales and the degree-angle calculations for launching spacecraft.
Hydrologists say that the dip in groundwater level is not just critical for maintaining a balance in water levels and meeting people’s requirements, but also maintaining the Earth’s gravitational balance. This will have long-ranging drastic impacts. Local efforts should start immediately, especially in densely-populated areas to recharge the groundwater.
A famous line from a poem goes: “Water, water everywhere, and not a drop to drink.” We are surrounded by water, but have little use for most of it. Hence, we resort to the over-exploitation of the water that we can use. But there is hope, which is bestowed upon us by nature. Water is never sitting still. Thanks to the water cycle, our planet’s water supply is constantly moving from one place to another and from one form to another. To ensure the seamless permanency of this cycle, all that humans need to do is maintain a balance.
The Paradoxical Value of Water
Through the diamond-water paradox, also known as the paradox of value, in ‘The Wealth of Nations’, Adam Smith illustrated the difference between the market value of a commodity and its practical utility. The paradox is that diamonds are more expensive than water, even though water is essential for survival, life. This is because diamonds are rare, desirable for jewellery, while water is more abundant and accessible
How much water is there on Earth?
If all of Earth’s water (oceans, icecaps and glaciers, lakes, rivers, groundwater, and water in the atmosphere was put into a sphere, then the diameter of that water ball would be about 1,385 km. The volume of all water would be about 1,386 million km3 (A cubic km of water equals about 1 trillion litres)
About 12,900 km3 of water, mostly in the form of water vapour, is in the atmosphere at any given time. If it all fell as precipitation at once, the Earth would be covered with only about 1 inch of water
Each day, 1,170 km3 of water evaporates or transpires into the atmosphere
Of the freshwater on Earth, much more is stored in the ground than is available in rivers and lakes. More than 8,400,000 km3 of freshwater is stored in the Earth, most within 3 km of the surface. But, if you really want to find freshwater, most is stored in the 29,200,000 km3 of water found in glaciers and icecaps, mainly in the polar regions