Earth's axis tilts 31.5 inches - and scientists pinpoint exactly who is to blame

Scientists have discovered that the Earth's axis tilted by 31.5 inches between 1993 and 2010 - and one of the reasons is the pumping of groundwater for irrigation and human use

The axis of Planet Earth has tilted by 31.5 inches (nearly 80cm) and humans are to blame for this, according to a new study.

Scientists studying the impact of climate change on our planet made the shocking discovery, which they attribute to the pumping of Earth's groundwater by humans. According to researchers, this can not only change the planet's rotation but also impact the rise of sea levels.

To put it into perspective, this water redistribution equates to approximately 0.24 inches of sea level rise, scientists found. It also altered the distribution of Earth's mass, leading to a drift of the rotational pole at a rate of 4.36cm per year between 1993 and 2010.

Ki-Weon Seo, a geophysicist at Seoul National University and study lead, said: "Earth's rotational pole actually changes a lot. Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole."

Earth's tilt is influenced by the distribution of mass - in this case, water - across the planet. Among the main factors contributing to this redistribution are the melting of glaciers and polar ice sheets from Greenland and Antarctica.

As ice melts, the water flows towards the equator, which alters Earth's balance and causes the axis to shift. The latest study has looked at data spanning 17 years, which shows the pumping of as much as 2,150 gigatons of groundwater has caused a change in the Earth's tilt of roughly 31.5 inches.

Researchers said the pumping is largely for irrigation and human use. Seo added: "Observing changes in Earth's rotational pole is useful for understanding continent-scale water storage variations." Linking these variations to water movement shows how everyday actions can impact the Earth on a global scale.

Seo added: "I'm very glad to find the unexplained cause of the rotation pole drift. On the other hand, as a resident of Earth and a father, I'm concerned and surprised that pumping groundwater is another source of sea-level rise."

The study, published in the journal Geophysical Research Letters, reads: "Melting of polar ice sheets and mountain glaciers has been understood as a main cause of sea level rise associated with contemporary climate warming. It has been proposed that an important anthropogenic contribution is sea level rise due to groundwater depletion resulting from irrigation. A climate model estimate for the period 1993–2010 gives total groundwater depletion of 2,150GTon, equivalent to global sea level rise of 6.24mm."

Surendra Adhikari, a research scientist at NASA's Jet Propulsion Laboratory, said in response to the study: "They've quantified the role of groundwater pumping on polar motion, and it's pretty significant." The findings are believed to open new doors for our understanding of climate change and our response to it.