New Dirt on Climate Change - Miller-McCune
Researchers have drilled into the middle of America in hopes of understanding past eras when the Earth burped out huge amounts of greenhouse gases.
For decades, geologists have been drilling — literally — for clues that would help them understand ancient wholesale changes in Earth’s climate, clues that could shed light on current global warming.
Usually, their efforts have been aimed at sea sediments taken from cores extracted hundreds of feet beneath the ocean floor. But in a more terrestrial project this past summer, an international geological team led by the University of New Hampshire began deep-core drilling at three sites in Wyoming’s Bighorn Basin east of Yellowstone National Park.
These six new core samples from Bighorn, until now better known for the dinosaurs in its past and the natural gas in its future, should make it possible to map ancient climate change at highly precise — in the realm of 1,000 to 10,000 year — intervals.
The 2.5-inch-diameter cores were drilled some 500 feet into the basin sediment in hopes that complex geochemical analyses could better explain the causes and effects of the biggest and best-studied period of known extreme global warming — the so-called Paleocene-Eocene Thermal Maximum.
PETM took place 56 million years ago and involved the release of as much as 7,000 gigatons of carbon in less than 10,000 years. By comparison, if released in a similar manner, all the world’s known fossil fuels today would only contribute 5,000 gigatons.
“These hyperthermals are random freak events, but there have been about 40 [of varying intensity] in the last 300 million years,” explains Gregory Retallack, a paleontologist at the University of Oregon in Eugene.
Because these cycles have already been identified in marine cores, these new continental measurements should make it possible to place these ancient regional climate and ecological changes into a global framework. In other words, climatologists will have a much better idea of how these ancient warming events affected the whole of Earth’s climate.