Global warming impacts Earth's rotation, posing a challenge to timekeeping
29 March 2024 19:29
Due to the melting of glaciers at both poles, the Earth has slightly slowed its rotation around its own axis. This is the conclusion of an analysis published by the "Nature" magazine. Global warming thus affects the way time is measured on our planet.
As we know, on the night from Saturday to Sunday (March 30/31) we will be switching our clocks from Standard Time to Daylight Saving Time. The hands will move from 2:00 am to 3:00 am GMT. We will have a shorter sleep but at least a somewhat longer day. This is not the only curiosity related to time that's worth remembering before the weekend.
As scientists have analyzed, due to global warming, which results in the melting of glaciers at both poles, the Earth began to rotate more slowly. As described on the TVN Meteo website, where the analysis published in the "Nature" journal is detailed, this may be significant for the way time is measured.
The Earth has slowed down. Here are the consequences
Scientists remind us that since the late 60s of the 20th century, the world has been using Universal Coordinated Time (UTC) to determine time zones. The calculations are based on precise atomic clocks. However, the rotational velocity of the Earth is not constant, therefore UTC time and the rotational time of our planet diverge.
The rotation of the Earth can be influenced by, for example, sea tides, the gravitational pull of the Moon, or significant movements of mass on the planet. Scientists have noticed that the rotational movement of the Earth prolonged by a few milliseconds per century, therefore in 1972, a system of leap seconds was introduced, which are added from time to time, to synchronize UTC time and solar time. Since that mentioned year 1972, 27 such seconds have been introduced.
Scientists determined that before 2020, the slower rotation of the Earth around its own axis was caused by the friction of tides on the ocean floors, associated with gravitational attraction by the Moon. However, according to the latest analyses, it is the melting of glaciers that has led to the deceleration of the Earth's movement. The reason is the shifting of water from melting glaciers towards the equator.
For me, the fact that humans have caused the change in the Earth's rotation is somehow astounding - admitted Duncan Agnew, a geophysicist from the Scripps Institution of Oceanography in California.
An interesting comparison was used by Ted Scambos, a glaciologist from the University of Colorado in Boulder, who stated that the Earth is like a skater rotating on an ice rink. When he keeps his arms raised up, he rotates faster, but when he keeps them lower, for example, close to his body, his movement slows down.
The trend of the Earth slowing down has however, in recent years, begun to reverse. This is related to processes occurring in the core of the planet. The phenomenon will affect how we calculate time on our planet. It may cause disturbances in the functioning of information systems. That is why experts would like to abandon leap seconds by 2035. They are particularly concerned about the moment when, instead of adding a second, it will be necessary to subtract one.
