Recent research highlights a direct correlation between rising global temperatures and the elongation of Earth’s days.
Studies indicate that as the planet warms, the length of each day increases subtly but measurably, as reported in the Proceedings of the National Academy of Sciences.
Polar Melting Shifts Earth’s Mass
The significant melting of ice sheets at the poles, due to increasing global temperatures, results in sea-level rise.
This mass redistribution enhances Earth’s equatorial bulge, thus extending the day at “an unprecedented rate,” the research notes.
Millennia of Gradual Change Accelerating
Historically, the Earth’s day length has extended by a few milliseconds per century, primarily influenced by the moon’s gravitational pull and the redistribution of molten rock in the planet’s mantle.
This natural pace is now dramatically increased by human-induced climate change.
Arctic and Antarctic Impacts
Melting ice sheets in regions like the Arctic and Antarctica are now major contributors to day lengthening.
The transportation of large amounts of mass from these poles to the equator was analyzed, highlighting its significant role in altering Earth’s rotation, the researchers report.
Earth’s Changing Shape and Rotation
As ice melts, Earth’s traditional oblate shape—a slightly flattened sphere—is becoming even more pronounced.
This change affects the rotational dynamics of the planet, a phenomenon extensively studied and documented in recent research.
A Century of Rapid Changes
Surendra Adhikari, a geophysicist at NASA’s Jet Propulsion Laboratory and a study author, remarked, “The same amount of increase in milliseconds per century that occurred in the thousands of years prior to the year 2000 is expected to occur in this century alone.”
This highlights the accelerated impact of modern climate change.
Climate Impact vs. Earth-Moon Dynamics
By the end of the 21st century, the impact of climate change alone could surpass the natural effects of Earth-moon dynamics.
This significant change in the lengthening of days is based on insights from Adhikari.
Understanding the Gravity of Climate Change
The study underlines the significant planetary-scale impact of contemporary climate changes.
Adhikari said, “It gives context as to the gravity, if I may, of the ongoing climate [emergency].”
Recent Decadal Observations
Over the last two decades, the rate of day lengthening has increased to about 1.33 milliseconds per century.
This represents a sharp rise compared to previous measurements.
Future Projections
The study has projected future acceleration rates.
Should greenhouse gas emissions continue unabated, the length of day could accelerate by an additional 2.62 milliseconds per century by the end of the 21st century.
Implications for Timekeeping
While these changes are minute, they hold significant implications for timekeeping.
Adhikari notes the potential need for adjustments in time measurement, including possibly implementing a “negative leap second” to correct for the inconsistencies in Earth’s rotation.
The Need for More Precise Timekeeping
As Earth’s rotational patterns become less consistent, society may need to turn to quantum or atomic clocks for more precise timekeeping and navigation, both on Earth and in space, suggests Adhikari.
This advancement could redefine how we manage and measure time in response to environmental changes.
