Washington, DC—New work from an international team including Carnegie’s Ken Caldeira demonstrates that the planet’s remaining fossil fuel resources would be sufficient to melt nearly all of Antarctica if burned, leading to a 50- or 60-meter (160- to 200-foot) rise in sea level. Because so many major cities are at or near sea level, this would put many highly populated areas where more than a billion people live under water, including New York City and Washington, DC. It is published in Science Advances.(more…)
For Earth Day this year, NASA invited people around the world to step outside to take a “selfie” and share it with the world on social media. NASA released Thursday a new view of our home planet created entirely from those photos.
The “Global Selfie” mosaic was built using more than 36,000 individual photographs drawn from the more than 50,000 images tagged #GlobalSelfie and posted on or around Earth Day, April 22, on Twitter, Instagram, Facebook, Google+ and Flickr. The project was designed to encourage environmental awareness and recognize the agency’s ongoing work to protect our home planet. (more…)
A team of scientists at NASA’s Johnson Space Center in Houston and the Jet Propulsion Laboratory in Pasadena, Calif., has found evidence of past water movement throughout a Martian meteorite, reviving debate in the scientific community over life on Mars.
In 1996, a group of scientists at Johnson led by David McKay, Everett Gibson and Kathie Thomas-Keprta published an article in Science announcing the discovery of biogenic evidence in the Allan Hills 84001(ALH84001) meteorite. In this new study, Gibson and his colleagues focused on structures deep within a 30-pound (13.7-kilogram) Martian meteorite known as Yamato 000593 (Y000593). The team reports that newly discovered different structures and compositional features within the larger Yamato meteorite suggest biological processes might have been at work on Mars hundreds of millions of years ago. (more…)
Pine Island Glacier is one of the biggest routes for ice to flow from Antarctica into the sea. The floating ice shelf at the glacier’s tip has been melting and thinning for the past four decades, causing the glacier to speed up and discharge more ice.
Understanding this ice shelf is a key for predicting sea-level rise in a warming world. A paper published Jan. 2 in the advance online version of the journal Scienceshows that the ice shelf melting depends on the local wind direction, which is tied to tropical changes associated with El Niño. (more…)
Much attention is paid to melting sea ice in the Arctic. But less clear is the situation on the other side of the planet. Despite warmer air and oceans, there’s more sea ice in Antarctica now than in the 1970s – a fact often pounced on by global warming skeptics. The latest numbers suggest the Antarctic sea ice may be heading toward a record high this year.
While changes in weather may play a big role in short-term changes in sea ice seen in the past couple of months, changes in winds have apparently led to the more general upward sea ice trend during the past few decades, according to University of Washington research. A new modeling study to be published in the Journal of Climate shows that stronger polar winds lead to an increase in Antarctic sea ice, even in a warming climate. (more…)
Study results could foreshadow earth’s future climate, MU researcher says
COLUMBIA, Mo. – For years, scientists have thought that a continental ice sheet formed during the Late Cretaceous Period more than 90 million years ago when the climate was much warmer than it is today. Now, a University of Missouri researcher has found evidence suggesting that no ice sheet formed at this time. This finding could help environmentalists and scientists predict what the earth’s climate will be as carbon dioxide levels continue to rise.
“Currently, carbon dioxide levels are just above 400 parts per million (ppm), up approximately 120 ppm in the last 150 years and rising about 2 ppm each year,” said Ken MacLeod, a professor of geological sciences at MU. “In our study, we found that during the Late Cretaceous Period, when carbon dioxide levels were around 1,000 ppm, there were no continental ice sheets on earth. So, if carbon dioxide levels continue to rise, the earth will be ice-free once the climate comes into balance with the higher levels.” (more…)
A mystery in the ocean near Antarctica has been solved by researchers who have long puzzled over how deep and mid-depth ocean waters are mixed.
They found that sea water mixes dramatically as it rushes over undersea mountains in Drake Passage – the channel between the southern tip of South America and the Antarctic continent. Mixing of water layers in the oceans is crucial in regulating the Earth’s climate and ocean currents.
The research provides insight for climate models which until now have lacked the detailed information on ocean mixing needed to provide accurate long-term climate projections. The study was carried out by the University of Exeter, the University of East Anglia, the University of Southampton, the Woods Hole Oceanographic Institution, the British Antarctic Survey and the Scottish Association for Marine Science and is published in the journal Nature. (more…)
Ice island reported by UD researcher breaks into mammoth ‘ice cubes’
The giant ice island that broke off Greenland’s Petermann Glacier in July 2012 has plowed into the ocean floor and shattered into a couple of mammoth “ice cubes” sitting in the ocean, according to the University of Delaware researcher who reported the initial glacial event last year.
Andreas Muenchow, an associate professor in UD’s College of Earth, Ocean, and Environment, said the ice chunk twice the size of Manhattan that snapped off the glacier in July 2012 ground into the ocean floor and has split into at least two ice islands and a number of large icebergs. (more…)