Here’s an unexpected effect of what is claimed to be climate change, but this is only one of several factors casing an increase in demands on water supplies in the Indian sub continent. This is from the i, 9 April
Groundwater levels on the Indian subcontinent have been depleted so badly by climate change intensive irrigation and population growth that it has caused the Earth to tilt on its axis, research shows.
The “polar rotation” of the planet – as the Earth spins on an axis topped and tailed by the north and south poles – has been shifting in recent years due to the melting of giant ice sheets in Greenland and Antarctica. This has significantly changed the distribution of the world’s mass as the melted ice flows into the oceans.
Now scientists have uncovered a further force on the earth’s rotation as India’s receding water table dramatically reduces the subcontinent’s mass. The weight change is the result of a massive redistribution of water as drought and over-use suck the moisture out of the ground much faster than it can be replaced by rainfall. The effect of changing “land water storage” – spreading out the water as it evaporates, forms clouds and rains elsewhere – is so strong that it is pushing the North Pole in an easterly direction, towards London.
“There is another mechanism – apart from the melting of the Greenland and Antarctic ice sheets – that is responsible for the dramatic eastward shift in polar motion,” said report author Surendra Adhikari of NASA’s Jet Propulsion Laboratory, which studied land water storage between 2002 and 2015. “The pattern of land water storage is such that there is a large mass deficit in the Indian Subcontinent and around the Caspian Sea,” he said.
The changing distribution of water away from the subcontinent has played a significant role in changing the tack of polar rotation in recent years, according to the research, published in the journal Science Advances.
Since observations began in 1899, the North Pole has been drifting southwards towards Hudson Bay, Canada, at a rate of 10cm a year. This is thought to stem from the collapse of the great Laurentide Ice Sheet in North America thousands of years ago. But the since the early part of this century the direction of the axis has shifted in a different direction and is now moving about 17cm east a year.
Greenland and Antarctica contain more than 99% of earth’s freshwater ice. The Greenland Ice Sheet is melting at a rate of 250 gigatonnes a year while Antarctica is losing 194 gigatonnes a year.