The changes in the inclination of the earth compared to the sun have reigned the movements of giant glacial calculations in the last 800,000 years, triggering the beginning and the end of eight glacial ages, suggests new research.
The new study revealed an “incredible correlation” between the inclination of the earth and the formation of glacial caps, the said principal author Stephen Barker. Based on these results, the researchers estimated that the next glacial period would be well advanced in 11,000 years – if it was not for global warming.
“The prediction is that the next ice age will start in the next 10,000 years,” said Barker, professor of earth sciences at Cardiff University in the United Kingdom, live. However, this result does not take into account our balloon greenhouse The emissions, which heat the planet to the point of preventing the ice age, he said.
Glacial sections, or glacial periods, are extremely cold sections of time that occur approximately every 100,000 years, covering a large part of the planet with huge glacial caps for thousands of years at the same time. Ice periods are separated by warmer interglacial periods, when the glacial caps withdraw towards the posts. The land is currently in an interglacial period, the last ice period having reached a peak About 20,000 years ago.
Inclination and oscillate
Scientists previously suggested that the position and angle of the earth compared to the sun affect the formation of the ice cap. In the early 1920s, Serbian scientist Milutin Milankovitch proposed that slight changes in the axial inclination of the earth and the shape of the earth’s orbit can trigger massive glacial events.
The researchers tested Milankovitch Theory Over the past 100 years. In particular, a 1976 study have found geological evidence showing that two of the parameters of the earth – the obliquity and the precession, or Changes in the axial inclination of the earth And How the axis oscillates around himRespectively – play a role in the hair removal and the decline of ice caps. But the precise role of one or the other parameter has remained clear.
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Now Barker and his colleagues say that they have finally untied the effects of these parameters.
The axis of the earth is currently tilted at an angle of 23.5 degrees Far from vertical because it revolves around the sun, affecting the amount of solar energy strikes each of the poles, in particular. But the inclination of the land axis naturally becomes more and smaller in a cycle which lasts around 41,000 years. The axis also vacillates around itself as a rotation outside the center, affecting the quantity of solar energy reaches the equatorial regions during the summer within the deadlines of around 21,000 years.
For the study, researchers have plotted known changes in obliquity and precession in the last 800,000 years. They also drawn up the expansion and retreat of ice caps during this period using existing data from microscopic shells, called forams, in oceanic sediment nuclei. The relative abundance of certain types of oxygen in forams reveals how long the ice caps have spread when the organisms were alive, said Barker.
The results of the combination of these plots were a “fall from the chair moment,” said Barker. “We have found this incredible correlation (…) which says that there is a direct relationship between the phasing of the obliquity and the precession, then the duration which results from the duration of the glacial caps to decompose,” he said.
In simple terms, the expansion of the ice cap of the poles towards the equator seems to be directly governed by the obliquity. The retirement of the Equator’s glacial caps to the posts, on the other hand, depends more on the precession. The researchers revealed their results in a study published Thursday (February 27) in the journal Science.
The results may not be surprising, since obliquity and precession affect the quantity of sun reaches the polar and equatorial regions respectively, said Barker. “Depending on where you are on earth, you will find more influence of precession or obliquity,” he said.
The plots were so neat that scientists extrapolated the data and estimated when the next glacial period would occur if the climate only changed according to natural cycles, said Barker. Additional research is necessary to pin the schedules, but the ice caps would probably start to extend between 10,000 and 11,000 years and reaching their maximum extent in the following 80,000 to 90,000 years. They would then take another 10,000 years to retire on the posts.
There are a lot of debates around the time of the following glaciation, but most experts agree that humans disrupt these cycles by global warming. “If the CO2 remains high, you will not get a new glaciation,” said Barker.
This does not mean that the cooking of the planet is a good idea, warned Barker. “What we don’t want is that people who want to emit more CO2 in the atmosphere to jump on it,” he said.
The point of this study and future research is rather to build an image of what the climate would do in the next 10,000 to 20,000 years without the impact of human activity, said Barker. The objective is then to provide a long-term estimate of the impact of humanity on the planet, he said.