Everything turned out to be much more serious
Scientists have found that climate change affects time more than previously thought. According to a new study, the consequences of man-made climate change are so enormous that they actually affect time.
Melting polar ice caused by global warming is altering the speed of Earth's rotation and increasing the length of each day, a trend that will accelerate over the course of this century as humans continue to rid themselves of pollution, according to a study published Monday in the journal Proceedings of the National Academy of Sciences. caused by the heating of the planet, notes CNN.
The changes are minor — just a few milliseconds a day, — but in our high-tech, hyper-connected world, they have an important impact on the computing systems we've come to rely on, including GPS.
This is another sign of the enormous impact that humans have on the planet. «This demonstrates the severity of ongoing climate change,» said Surendra Adhikari, a geophysicist at NASA's Jet Propulsion Laboratory and author of the report.
The number of hours, minutes and seconds that make up each Earth day is determined by the speed of the Earth's rotation, which is influenced by a complex set of factors. These include processes in the planet's liquid core, the ongoing impact of the melting of huge glaciers from the last ice age, and the melting of polar ice caps due to climate change.
But for millennia, the Moon has dominated, increasing the length of the day by a few milliseconds per century. The Moon exerts a gravitational pull on the Earth, causing the oceans to move toward it, gradually slowing the Earth's rotation.
Scientists have previously linked the melting of polar ice caps to the lengthening of days, but the new study suggests that global warming is having a greater effect on time than recent studies have shown.
In the past, the impact of climate change over time «was not so dramatic,» said Benedict Soja, study author and assistant professor of space geodesy at the Swiss university ETH in Zurich.
But that may change. If the world continues to pump out planet-heating pollution, «climate change could become the new dominant factor,» overtaking the role of the moon, he told CNN.
It works like this: As humans warm the earth, glaciers and ice sheets melt, and meltwater flows from the poles to the equator. This changes the shape of the planet — it becomes flatter at the poles and more convex in the middle, which slows down its rotation.
This process is often compared to a figure skater spinning on ice. When a skater pulls his arms toward his body, he rotates faster. But if he extends his arms forward, away from his body, his rotation slows down.
A team of international scientists analyzed the 200-year period between 1900 and 2100, using observational data and climate models, to understand how climate change affected day length in the past and predict its role in the future.
Scientists found that the impact of climate change on daylight hours has increased significantly.
Rising sea levels caused by climate change have caused the length of the day to fluctuate between 0.3 and 1 millisecond in the 20th century. However, over the past two decades, scientists estimate that the length of the day is increasing by 1.33 milliseconds per century, which is «significantly higher than at any time in the 20th century,» the report said.
The report It says that if planet-heating pollution continues to rise, leading to warming oceans and accelerating ice melt in Greenland and Antarctica, the pace of change will accelerate rapidly. If the world fails to curb emissions, climate change could add 2.62 milliseconds to the length of the day by the end of the century, exceeding the moon's natural influence.
“In just 200 years, we will change the Earth's climate system so much that we will see its influence on the very rotation of the Earth,” Adhikari said in an interview with CNN.
A few milliseconds of extra time per day may not be noticeable to humans, but they influence the development of technology, CNN emphasizes.
Accurate time tracking is vital to GPS, which everyone with a smartphone has, as well as other communication and navigation systems. They use highly accurate atomic time, based on the spin rate of certain atoms.
Since the late 1960s, the world began using Coordinated Universal Time (UTC) to determine time zones. UTC time is based on atomic clocks, but still follows the rotation of the planet. This means that at some point, «leap seconds» must be added or subtracted to remain consistent with the Earth's rotation.
According to Mostafa Kiani Shahvandi, study author and geologist at ETH Zurich, some studies have also shown a correlation between increasing day length and increasing the number of earthquakes. But the link remains speculative and much more research is needed to establish any clear connection, he told CNN.
A paper on the same topic published in March concluded that while climate change is increasingly slowing the Earth's rotation, processes at the Earth's core may be more important and actually speeding it up by shortening the length of the day.
< “What we did was go a little further and rethink these trends,” notes Shahvandi. The researchers found that any impact from the molten core outweighed the impact of climate change.
Duncan Agnew, a professor of geophysics at the University of California, San Diego and author of the March study, said the new study remains consistent with his research, «and is valuable because it extends the results into the future and looks at more than one climate scenario.» /p>
Jacqueline McCleary, an assistant professor of physics at Northeastern University who was not involved in the study, said the new study helps clarify «a decades-long debate about exactly what role climate change will play in changing day lengths.» .
While there is now general agreement that climate change will have a «net effect of lengthening days,» she told CNN, there is still uncertainty about which time-shaping processes will dominate in this century. This study concludes that climate change is now the second most important factor, she said.
“This is a sobering conclusion,” said Soja of ETH Zurich. “We have to consider that we are now influencing the Earth's orientation in space so much that we are dominating the effects that have been going on for billions of years.“
Свежие комментарии