mef you could go back to the Eemian period – oh 116,000 to 129,000 years ago – you would feel right at home. OK, the woolly mammoth lumbering about might set you back, as might the hippopotamus roam freely across the streets of Europe one day. But for the climate, things would not be so different. Global average temperatures are around today 1ºC warmer than they were in the pre-industrial era, which led to our extreme weather and other events: heat waves, wildfires, droughts, floods, major storms, ferocious hurricanes, and more.
In Yemen, things were even hotter, close to 2ºC warmer than in the pre-industrial era, and will certainly lead to harsher conditions. Individual weather events like hurricanes are too short to be preserved in the so-called climate archive that Earth scientists use to study climate history, especially deep cores drilled from ice sheets, the ocean floor, lake silt and the ground. But computer models combined with the data from the cores suggest a disturbed Eemian.
“We are not exclusively tied to the climate archive,” says Syee Weldeab, professor of Earth Sciences at the University of California, Santa Barbara. “We can run [computer] models that change [the weather] as we increase the energy in the atmosphere and ocean.”
One study in Research Gateway Yemen’s hurricanes were found to be stronger and further north than those observed today – even increasing the frequency of winter storms, which lasted much longer than the contemporary hurricane season. Otherin Scientific Reports, he found Eemian droughts and brush fires in Australia that lasted hundreds of years at the time. Still more research in the Proceedings of the National Academy of Sciences Yemen was reportedly hit by “massive storms” more intense than any historically observed. If Yemen is the history of the World, it is also a reflection of the Earth – a possible warning of the kind of climate pressure we face if we allow our global temperature to slip past the 1ºC to 2ºC threshold defined by Yemen.
Read more: When Climate Change Is Discovered, There Is No Such Thing as a New Normal
Regardless of how violent the Eemian was, planetary scientists today fear that our current era is the warmest on Earth since a period that happened so long ago. After all, it took Yemen more than 16 thousand years to evolve and evolve. Man-made climate change required less than 300 years—since the beginning of the fossil industrial age in 1760—causing such disruption in the only world we have.
“It’s amazing,” says Gifford Miller, distinguished professor emeritus of geological sciences at the University of Colorado, Boulder. “I think a lot of people struggle to imagine that tiny people can change the energy balance so much that it fundamentally changes the climate.”
Why the World Runs a Fever
Unlike climate change today, global warming and the aftermath of the Yemeni weather had little to do with greenhouse gases in the atmosphere. Analysis of the archival cores shows that the concentration of carbon dioxide and other greenhouse gases in the atmosphere back then was about 280 parts per million (ppm), according to Miller. today, the National Oceanic and Atmospheric Administration puts the alarming figure at 417.06 sq m. Even if people turned off the CO2 spigot today, the emissions already in the system would continue to heat the world for years.
So, if greenhouse gases played a small role in Yemen’s extreme warming, what was responsible? The answer is the angle of the Earth and the relative positions of the planet and the sun. The Earth does not spin evenly around its axis, but it can tilt like a top – a process called press. At the beginning of the Eminence, that wobble pointed the North Pole toward the sun, slightly increasing the 23.7 degree angle that Earth normally maintains, and exposing the northern hemisphere to more sunlight than it would normally.
“The north got closer to the sun,” says Miller, “and the planet was absorbing about 9% more solar energy.”
Then too, it was so close to the Earth and the sun. The average distance between the two bodies It is 150 million km (93 million miles.). But that figure changes during the year. Once every 12 months, the Earth reaches something called a aphelion—or the longest approach — stretching out to about 150 million km (94.5 million mi.). Six months later, he reaches a periheliondrawing closer to 147 million km (91.4 million mi.).
But eccentricity in the Earth’s orbit can sometimes disrupt this cycle. Periodically the planet will linger close to the perihelion distance—generally for a few thousand years or so. A few millennia is nothing on a cosmic scale, but, as with hemispheric tilt, the phenomenon can greatly affect energy absorption. “The combination of those two,” says Miller, “as a result of higher inclination and being closer to the sun resulted in a total increase of 12% in solar energy received.”
The Parallels Between Now and Now
That 12% made a big difference in many ways like the ones we are seeing with contemporary global warming. For starters, the oceans are therewhich absorbs huge amounts of heat and evaporates more water vapor in the process – a kind of feedback loop because water vapor itself is a powerful greenhouse gas.
Plant migration northward also contributed to climate change in Yemen, suggesting ancient, modified DNA from the Canadian Arctic—and it’s there. happening today too. At warm temperatures, Arctic areas that were once unwelcoming to trees begin to support them. Leaf canopies cover up bright, bright snow that would normally reflect sunlight back into space. Instead the leaves absorb the heat, warming up the Arctic forests and causing them, like the oceans, to release temperature-rising water vapor into the atmosphere.
Then also there is the smallest matter called methane hydrates – again, Eemian and probably contemporary problem. A mixture of methane and water, methane hydrates usually remain in a frozen state in the deep ocean. As the ocean warms, however, the deposits melt and separate, releasing the methane itself – another powerful greenhouse gas, allowing it to rise up in the water and escape into the atmosphere.
“There is a long-term climate feedback process,” says Weldeab, “something that increases the warming.”
The Eemian eventually came to an end after the Earth straightened its inclination slightly and returned to its normal aphelion-perihelion cycle; by the time it happened – 13,000 years after the start of the Eminem – the ice from the previous glacier had been lost. Compare that slow melting with the decades it has taken human-caused climate change to cause such damage to vast areas of ice in Greenland and Antarctica and it creates the probability that An ice-free Arctic summer as early as 2030. All in all, it only took humans 263 years, from the start of the Industrial Age, to create their own overheated Yemen. Unlike the last, there is no natural process like the realignment of the planet that will step in and set things right. We made the mess – and it’s ours to clean up.
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