Earth May Be Close to ‘Threshold of Catastrophe’

Earth May Be Close to ‘Threshold of Catastrophe’
By Tia Ghose, LiveScience Staff Writer | October 2, 2017 05:25pm ET

Earth May Be Close to 'Threshold of Catastrophe'

A NASA camera on the Deep Space Climate Observatory satellite captured its first view of the entire sunlit side of the spherical planet Earth, on July 6, 2015.

Credit: NASA

The amount of carbon dioxide that humans will have released into the atmosphere by 2100 may be enough to trigger a sixth mass extinction, a new study suggests.

The huge spike in CO2 levels over the past century may put the world dangerously close to a “threshold of catastrophe,” after which environmental instability and mass die-offs become inevitable, the new mathematical analysis finds.

Even if a mass extinction is in the cards, however, it likely wouldn’t be evident immediately. Rather, the process could take 10,000 years to play out, said study co-author Daniel Rothman, a geophysicist at the Massachusetts Institute of Technology. [7 Iconic Animals Humans Are Driving to Extinction]

However, slashing carbon emissions dramatically in the coming years may also be enough to prevent such global catastrophe, said Lee Kump, a geoscientist at Pennsylvania State University who was not involved in the study.

Over Earth’s 4.5-billion-year history, life has seen a lot of boom and bust times. In the past half-billion years alone, five major extinctions have wiped out huge swaths of life: the Ordovician-Silurian mass extinction, the Late Devonian mass extinction, the Permian mass extinction, the Triassic-Jurassic mass extinction and the Cretaceous-Tertiary mass extinction that wiped out the dinosaurs. The most severe was the Permian extinction, or “The Great Dying,” when over 95 percent of marine life and 70 percent of land-based life died off.

All these major extinctions have one similarity.

“Every time there’s been a major mass extinction — one of the big five — there’s been a serious disruption of the global carbon cycle,” Rothman said. It could be a direct link between CO2 and death due ocean acidification or an indirect link, as carbon dioxide emissions can warm a planet to unlivable temperatures and have even been linked with volcanic eruptions and the related cooling of the atmosphere.

For instance, at the end of the Permian period, about 252 million years ago, ocean carbon dioxide levels skyrocketed, marine rocks reveal. (Carbon dioxide that is in the air gradually dissolves into the ocean’s surface and eventually enters the deep ocean.)  However, carbon doesn’t always equal assured doom for the planet. It’s possible that a change in carbon levels in the atmosphere and oceans are markers for rapid environmental change, which could be the underlying cause of extinctions. In addition, rocks from the past reveal many other “carbon excursions” — or rises in atmospheric or ocean levels of carbon — that did not result in mass extinctions, Rothman said. [Ocean Acidification: The Other Carbon Dioxide Threat]

So what distinguishes the deadly carbon excursions from the ones that don’t cause mass dying?

In the new study, which was published Sept. 20 in the journal Science Advances, the scientists assumed that two factors may play a role: the rate at which carbon levels increase, and the total amount of time that change is sustained, Rothman said.

To calculate those values, Rothman looked at data on carbon isotopes, or versions of the element with differing numbers of neutrons, from rock samples from 31 geologic periods over the past 540 million years. Determining the length and magnitude of rises in atmospheric carbon can be tricky because some periods have thorough rock samples while others are sparsely represented, Rothman said.

From that data, Rothman and his colleagues identified the rates of carbon change and total carbon input that seemed to be correlated to extinctions in the geologic record. Then, they extrapolated to the present day, in which humans are adding carbon to the atmosphere at a furious rate.

Rothman calculated that adding about 310 gigatons of carbon to the oceans was enough to trigger mass extinctions in the past, although there is huge uncertainty in that number, Rothman said.

“Most every scenario that’s been studied for how things will play out, as far as emissions are concerned, suggest on the order of 300 gigatons or more of carbon will be added to the oceans before the end of the century,” Rothman said.

What happens the day after that threshold is reached?

“We run the risk of a series of positive feedbacks in which mass extinction could conceivably be the result,” Rothman said.

Of course, those effects wouldn’t be felt immediately; it could take 10,000 years for the die-off to result. And there’s a lot of uncertainty in the estimates, Rothman added.

“I think it’s a really useful approach, but there are always limitations when we’re working in deep time,” Kump told Live Science. “One of the limitations is that Rothman had to accept the state of our understanding of the timing and duration of these disturbances.”

But even with that uncertainty, “clearly the rate of fossil fuel burning today rivals, if not exceeds, the rate of carbon cycle perturbation in the past” associated with mass extinctions, Kump said.

Because the rate of carbon rise is so steep currently, the best option for preventing eventual catastrophe is to ensure the duration of the carbon increase is short, he said.

“If we can rein ourselves in, we can avoid the Permian catastrophe,” Kump said.

Originally published on Live Science.

NASA to Update EM-1 Schedule in October

NASA to Update EM-1 Schedule in October
By Jeff Foust, SpaceNews Writer | September 30, 2017 07:31am ET

NASA to Update EM-1 Schedule in October

NASA will provide an update for the schedule of Exploration Mission 1, the first launch of the Space Launch System, in October.

Credit: NASA

SYDNEY — NASA plans to publish a revised launch date for the first mission of its Space Launch System in October amid reports that the flight has been pushed back to nearly the end of 2019.

In a statement to SpaceNews Sept. 22, NASA spokesperson Kathryn Hambleton said that NASA will issue an update for the scheduled launch of Exploration Mission (EM) 1 in October.

That schedule, she said, is being influenced by several issues, ranging from work on the European-provided service module for the Orion spacecraft and the impact of several weather events, including both the tornado that struck the Michoud Assembly Facility in New Orleans and Hurricanes Harvey and Irma, which shut down the Johnson Space Center in Houston and Kennedy Space Center in Florida respectively by more than a week.

“All of these factors are influencing launch planning and will result in an EM-1 mission in 2019,” she said. “An update to the agency’s target for EM-1 launch is expected in October.”

That statement came after NASASpaceFlight.com, citing internal documents, reported Sept. 22 that the launch date for EM-1 had been delayed until no earlier than Dec. 15, 2019, with EM-2, the first SLS mission to carry a crew, delayed until no earlier than June 2022.

NASA had already indicated that EM-1, originally scheduled for launch as soon as 2017, would be delayed until some time in 2019. In an April response to a U.S. Government Accountability Office report, Bill Gerstenmaier, NASA associate administrator for human exploration and operations, said that the agency was in the process of establishing a new launch date for EM-1 in 2019 after the report cited issues that threatened to delay the then-scheduled date of November 2018.

NASA confirmed those plans in May when the agency announced that it would not put a crew on EM-1 after performing a study at the request of the White House regarding that. The agency concluded that while it would be feasible to do so, there were cost, schedule and risk issues in doing so.

At that time Gerstenmaier acknowledged schedule issues, including a recent welding mishap at Michoud that damaged a liquid hydrogen tank being built for SLS qualification tests, would push EM-1 to 2019. “We’re probably a month or two away from coming up with a final schedule,” he said at the time, although the agency has not provided a schedule update since the May announcement.

At that time, Gerstenmaier also said that the EM-1 delay would also likely push back EM-2, which was then scheduled for August 2021. Part of any delay is the need to reconfigure ground systems at the Kennedy Space Center after the EM-1 launch to support the use of an upgraded version of the SLS with the more powerful Exploration Upper Stage.

This story was provided by SpaceNews, dedicated to covering all aspects of the space industry.

NASA and Russia Partner Up for Crewed Deep-Space Missions

NASA and Russia Partner Up for Crewed Deep-Space Missions
By Hanneke Weitering, Space.com Staff Writer | September 27, 2017 04:35pm ET

Partner Series
NASA and Russia Partner Up for Crewed Deep-Space Missions

An artist’s concept of NASA’s deep-space gateway, an orbital outpost in cislunar space that would serve as a stepping stone for crewed Mars missions.

Credit: NASA

NASA and the Russian space agency Roscosmos have announced a new partnership for human exploration of the moon and deep space. Both agencies signed a joint statement on cooperation today (Sept. 27) at the 68th International Astronautical Congress in Adelaide, Australia.

The decision to partner with Russia on human missions to the moon and beyond came about as NASA continues to flesh out ideas for its “deep-space gateway” concept, a mission architecture designed to send astronauts into cislunar space — or lunar orbit — by the 2020s. Traveling to and from cislunar space will help NASA and its partners gain the knowledge and experience necessary to venture beyond the moon and into deep space.

A crewed mission to the moon and ultimately deep space would likely involve NASA’s gigantic new Space Launch System (SLS) rocket and the Orion space capsule. “This plan challenges our current capabilities in human spaceflight and will benefit from engagement by multiple countries and U.S. industry,” NASA officials said in a statement. [Photos: NASA’s Space Launch System for Deep Space Flights]

Roscosmos and NASA already work together with other space agencies around the world to run research projects aboard the International Space Station. Now the international partners will work together to build a miniature space station in lunar orbit – a type of infrastructure that could serve as a steppingstone for future crewed missions to Mars, NASA officials said.

In a separate statement, Roscosmos officials said the new partnership would “develop international technical standards … for the establishment of the station in the near-moon orbit.” According the Roscosmos, the partners also discussed the possibility of using a Russian superheavy rocket to complete construction of the orbital moon station.

“At the first stage, [the deep-space gateway] is supposed to use the American superheavy SLS in parallel with the domestic heavy rockets Proton-M and Angara-A5M,” Roscosmos officials said. “After the creation of the Russian superheavy rocket, it will also be used [for] the lunar orbital station.”

However, those plans are not concrete at this point, and NASA will continue to work with Roscosmos to research the best ways to transport astronauts to and from cislunar space.

“While the deep space gateway is still in concept formulation, NASA is pleased to see growing international interest in moving into cislunar space as the next step for advancing human space exploration,” Robert Lightfoot, NASA’s acting administrator, said in a statement.

“Statements such as this one signed with Roscosmos show the gateway concept as an enabler to the kind of exploration architecture that is affordable and sustainable,” Lightfoot added.

Meanwhile, NASA is also asking the private space industry to contribute to the deep-space gateway. The agency has already awarded contracts for deep-space habitat designs to Bigelow Airspace, Lockheed Martin, Orbital ATK and others.

Email Hanneke Weitering at hweitering@space.com or follow her @hannekescience. Follow us @SpacedotcomFacebook and Google+. Original article on Space.com.