Sea levels have already risen 3 inches on average since 1992, with some areas experiencing as much as a 9-inch rise. Photo credit: NASA / Saskia Madlener
New research underway indicates that at least three feet of global sea level rise is near certain, National Aeronautics and Space Administration (NASA) scientists warned Wednesday.
That’s the higher range of the one to three feet level of rise the UN Intergovernmental Panel on Climate Change (IPCC) gave in its 2013 assessment.
Sea levels have already risen three inches on average since 1992, with some areas experiencing as much as a 9-inch rise.
“Given what we know now about how the ocean expands as it warms and how ice sheets and glaciers are adding water to the seas, it’s pretty certain we are locked into at least three feet of sea level rise and probably more,” said Steve Nerem of the University of Colorado, Boulder and lead of NASA’s interdisciplinary Sea Level Change Team. “But we don’t know whether it will happen within a century or somewhat longer.”
The Greenland ice sheet has contributed more greatly to sea level rise, losing an average of 303 gigatons of ice a year over the past decade, while the Antarctic ice sheet has lost an average of 118 gigatons a year. But scientists at NASA and the University of California, Irvine warned last year that glaciers in the West Antarctic “have passed the point of no return.”
Glaciologist Eric Rignot of the UC-Irvine and NASA’s JPL and lead author of the West Antarctic study, stated Wednesday that East Antarctica’s ice sheet remains a wildcard.
“The prevailing view among specialists has been that East Antarctica is stable, but we don’t really know,” Rignot stated. “Some of the signs we see in the satellite data right now are red flags that these glaciers might not be as stable as we once thought.”
Exactly how much rise will happen and when is uncertain, they say. “We’ve seen from the paleoclimate record that sea level rise of as much as 10 feet in a century or two is possible, if the ice sheets fall apart rapidly,” said Tom Wagner, the cryosphere program scientist at NASA Headquarters in Washington. “We’re seeing evidence that the ice sheets are waking up, but we need to understand them better before we can say we’re in a new era of rapid ice loss.”
As the largest single chunk of melting snow and ice in the world, the massive ice sheet that covers about 80 percent of Greenland is recognized as the biggest potential contributor to rising sea levels due to glacial meltwater.
Until now, however, scientists’ attention has mostly focused on the ice sheet’s aquamarine lakes — bodies of meltwater that tend to abruptly drain — and on monster chunks of ice that slide into the ocean to become icebergs.
But a new study involving City College of New York scientistMarco Tedesco and a UCLA team reveals a vast network of little-understood rivers and streams flowing on top of the ice sheet that could be responsible for at least as much, if not more, sea-level rise as the other two sources combined.
“It’s the world’s biggest water park, with magnificent and beautiful — but deadly — rushing blue rivers cutting canyons into the ice,” said Laurence C. Smith, the study’s lead author and the chair of UCLA’s geography department.
The group also specifically examined the Isortoq River, which exits the ice sheet on land and drains about one-fifth of the mapped networks. Its output is critical because it’s a key element of the Modele Atmospherique Regional, or MAR, a climate model used by the Intergovernmental Panel on Climate Change to develop worldwide responses to global warming. The researchers found that the Isortoq’s amount of discharge was more than 25 percent less than the model predicted.
“The model automatically assumes that the meltwater is going directly to the ocean,” said Professor Tedesco, a co-author and head of City College’s Cryospheric Processes Laboratory, which operates MAR. “Some can get retained under the ice. More research is definitely needed.”
“If we can get better estimates, then we can have better projections for the extent and the impact of global warming,” said Professor Tedesco. “Greenland is really the big player for sea level rise in the future, so improving climate models is extremely crucial.”
The above story is based on materials provided by City College of New York. Note: Materials may be edited for content and length.
Artist Nickolay Lamm discusses the motive behind his sea level rise photographs.
This past year has been a busy one for the International Space Station. With a variety of new investigations,
facilities, researchers, data and results, the space station Program Science Office has had much to share. These investigations benefit life on Earth, inform future space exploration and advance fundamental scientific understanding.
In the International Space Station’s Kibo laboratory, Japan Aerospace Exploration Agency (JAXA) astronaut Akihiko Hoshide, Expedition 33 flight engineer, works on the Multipurpose Small Payload Rack in preparation for the arrival of the JAXA Medaka Osteoclast payload on the Soyuz TMA-06M spacecraft on Oct. 25. (NASA)
“This has been an amazing year for the space station,” said International Space Station Program Scientist Julie Robinson, Ph.D. “We have achieved and exceeded our research goals for the first year of full research use.”
Two ongoing investigations that continue to stimulate interest are Robonaut and the Alpha Magnetic Spectrometer-02, or AMS. Robonaut’s “human” capabilities are being tested methodically, expanding robotics technology. AMS is collecting charged particles for scientists to sift through to find dark matter and anti-matter. This data could help unlock the secrets of our universe — and possibly change the world of physics. AMS already has measured over 26 billion charged particles.
Human research studies have shown that during their stay aboard the space station, astronauts can combat bone loss by using the Advanced Resistive Exercise Device, or ARED, for high intensity workouts in addition to a proper diet and an intake of vitamin D. This countermeasure also aids in rebuilding their bones once they return to Earth. These studies could have profound effects on future space exploration, as well as the aging population on Earth.
Education investigations, like the YouTube Space Lab competition and others, are part of every expedition and work to inspire students of all ages. YouTube Space Lab had an international following this year, culminating in a live webcast of the winning student investigations performed by Expedition 33 Commander Sunita Williams. More than 2,000 entries focusing on the subjects of physics and biology were received from more than 80 countries.
Downlinked from the International Space Station, this image shows the wild fires in the Southwest United States in early June 2012.(NASA)
Physical science investigations — crystal growth, colloid and flame investigations — continue. Each study is adding to the knowledge database. This knowledge expansion provides benefits for future exploration, as well as life on Earth. Some interesting results were discovered in the Flame Extinguishment Experiment, or FLEX. For the first time, researchers observed low-temperature, soot-free “cool” flames — proving two different modes of fuel combustion and flame extinction in microgravity: one was visible to the naked eye and one was not.
Earth and space science investigations include observational studies that look at changes involving pollution; sea levels; urban sprawl and population growth; climate and temperature, along with storms, floods, fires and volcanic eruptions; and other dynamic events. Images taken during these observations provide researchers with data important to understanding the planet from a different perspective and provide a way to track these changes over long periods of time. The information learned from these studies enhances our understanding of Earth science. The International Space Station SERVIR Environmental Research and Visualization System, or ISERV, was delivered to the station last July. It is a remote-controlled Earth imaging system designed to capture imagery of identified areas for environmental studies and disaster analysis from the vantage point of the station.
Researchers are always working to increase the understanding of biological processes in microgravity and how this information can help people on Earth. Two highlights from the past year include studies of fish and yeast organisms. The Aquatic Habitat received its first inhabitants in 2012: Medaka fish. These translucent fish allow for easy observation of their skeletal systems, providing more insight into bone and muscle atrophy (medical issues for astronauts and the aging population) and radiation effects.
Several tiny satellites are featured in this image taken by an Expedition 33 crew member. The satellites were released on Oct. 4 outside the Kibo laboratory using a Small Satellite Orbital Deployer attached to the Japanese module’s robotic arm. (NASA)
Genotypic and Phenotypic Responses of Candida albicans to Spaceflight, or Micro-6, is studying the health risks of the opportunistic yeast Candida albicans.. This yeast is naturally occurring in humans, and researchers want to understand why it becomes more powerful (rapidly reproducing in the human body) and infectious when the human immune system is under stress. What is learned from this study will not only benefit people on Earth who battle this opportunistic pathogen, but it also will benefit future space travelers.
Technology demonstrations also are part of the suite of investigations being examined on the orbiting outpost. One of the many highlights this year is the Robotic Refueling Mission, or RRM. This mission intends to validate technologies, tools and procedures needed to robotically repair and refuel satellites in orbit. This ability is particularly helpful for extending the service life of many satellites, particularly those not originally built for servicing, referred to as non-cooperative satellites.
Several new facilities were delivered to the space station and allow for an array of new research projects. The Japanese Experiment Module Small Satellite Orbital Deployer, or J-SSOD, changed the way mini-satellites can be deployed to their optimal orbit, allowing for greater flexibility, operational control and significant monetary savings. A Gravitational Biology Lab also was delivered to the orbiting laboratory. The centrifuge allows for biological experimentation in artificial gravity — from zero gravity to twice Earth’s normal gravity — for prolonged periods of time. This lab is useful for biological organism research, and it could lead to advances in medications and vaccines, agricultural controls and discoveries in genetics.
The Center for the Advancement of Science in Space, or CASIS, the nonprofit organization in charge of promoting and managing research aboard the space station’s U.S. National Laboratory segment, announced several requests for solicitations. Its current focus is on advancing protein crystallization, materials science and Earth observational science.
Expedition 32 Flight Engineer Sunita Williams works at the Microgravity Science Glovebox in the Destiny laboratory of the International Space Station, August 2012. (NASA)
With its first commercial resupply service mission, SpaceX has increased the capability to return science samples, among other items, to Earth. The return of these samples expedites research results. This ability also frees up stowage space on the station.
This year also saw the release of the Space Station Benefits for Humanity book, as well as the Space Station Education publication. These publications help the public understand how research in orbit helps people on Earth, and they provide many educational activities to engage students of all ages.
The research carried out aboard the space station continues to provide new insights for scientists. “We see a dramatic increase in scientific publications and their quality,” said Robinson. “Extraordinary benefits from this research are developing. The International Space Station is helping to save lives and make our economy stronger.”
The next ten years should prove to be very exciting regarding new discoveries that will advance human space travel and benefit people on Earth in a host of different arenas.
You can read more about these investigations, and others, on the space station latest news page.
Editors note: Original article can be found here.
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