Changes in Earth's orbit may have triggered ancient warming event
Changes in Earth's orbit that favored hotter conditions may have helped trigger a rapid global warming event 56 million years ago that is considered an analogue for modern climate change, according to an international team of scientists.
"The Paleocene-Eocene Thermal Maximum is the closest thing we have in the geologic record to anything like what we're experiencing now and may experience in the future with climate change," said Lee Kump, professor of geosciences at Penn State. "There has been a lot of interest in better resolving that history, and our work addresses important questions about what triggered the event and the rate of carbon emissions."
The scientists analyzed core samples from a well-preserved record of the PETM near the Maryland coast using astrochronology, a technique for dating sediments against orbital patterns that occur over tens to hundreds of thousands of years, known as Milankovitch cycles.
They found the shape of Earth's orbit, or eccentricity, and the wobble in its rotation, or precession, favored hotter conditions at the onset of the PETM and that these orbital configurations together may have played a role in triggering the event.
"An orbital trigger may have led to the carbon release that caused several degrees of global warming during the PETM as opposed to what's a more popular interpretation at the moment that massive volcanism released the carbon and triggered the event," said Kump, the John Leone Dean in the College of Earth and Mineral Sciences.
The findings, published in the journal Nature Communications, also indicated the onset of the PETM lasted about 6,000 years. Previous estimates have ranged from several years to tens of thousands of years. The timing is important to
Read more on tech.hindustantimes.com
