Ancient soil from secret Greenland base suggests Earth could lose a lot of ice

Ancient soil from secret Greenland base suggests Earth could lose a lot of ice

SOURCE: Science DATE: October 29, 2019 SNIP: In one of the Cold War’s oddest experiments, the United States dug a 300-meter-long military base called Camp Century into the ice of northwest Greenland in the early 1960s, powered it with a nuclear reactor, and set out to test the feasibility of shuttling nuclear missiles beneath the ice. A constant struggle against intruding snow doomed the base, which was abandoned in 1966. But Camp Century has left a lasting, entirely nonmilitary legacy: a 1.3-kilometer-long ice core drilled at the site. The core, extracted by a team that included glaciologist Chester Langway, yielded a record of past temperatures that helped kick off studies of Earth’s ancient climate. And last week, dozens of scientists met here at the University of Vermont (UVM) to take stock of another gift from the core: mud from Greenland’s ancient land surface, serendipitously discovered in archived samples. New analyses of the mud suggest Greenland’s massive ice sheet was largely absent in a warm period during the past million years when the global climate was much like today’s. The samples likely have more stories to tell, UVM geophysicist Paul Bierman said at the gathering, which he organized to discuss recent results and plan further analyses. Drew Christ, a geochemist in the lab who prepared the samples, sent thawed samples to the lab of Eric Steig, a glaciologist at the University of Washington in Seattle, who measured ratios of oxygen isotopes to tease out past temperature. He also sent pieces of frozen muck to Tammy Rittenour, a geologist at Utah State University in Logan who specializes in luminescence dating: blasting...
The Climate Has Always Changed. Why Is This Time so Much Worse?

The Climate Has Always Changed. Why Is This Time so Much Worse?

SOURCE: NexusMedia DATE: July 19, 2018 SNIP: A recently released study brought sobering news about the future effects of climate change, predicting they could be twice as bad as current models have projected under a “business-as-usual” scenario — and then some. From the study: “Comparison of palaeo observations with climate model results suggests that, due to the lack of certain feedback processes, model-based climate projections may underestimate long-term warming in response to future radiative forcing by as much as a factor of two, and thus may also underestimate centennial-to-millennial-scale sea-level rise.” Two of the study’s co-authors, Katrin Meissner, director of the University of New South Wales Climate Change Research Centre, and Alan C. Mix, distinguished professor of earth, ocean, and atmospheric sciences at Oregon State University, recently spoke with Nexus Media about the study, which was conducted by an international team of researchers from 17 countries. A snippet from the interview: “It is reasonably well known that in the Pliocene time interval, roughly 2–5 million years ago, CO2 was a bit higher than today. The exact cause isn’t known, but it came from some geologic reservoirs where CO2 is locked up today. These reservoirs are things like organic matter in soil and in sediments under the ocean. It isn’t a lot of carbon in every square meter, or square foot, but there is a huge area, so it adds up. Carbon is also stored today in permafrost, and in the deep ocean. The fact that the Pliocene was both a bit warmer than today and had a bit more CO2 in the atmosphere is important, because it shows that warmth, however...