Carbon Dioxide Breaking Down Marine Ecosystems. Oceans acidifying at unprecedented speed - environment - 01 March 2012. Humanity's greenhouse gas emissions may be acidifying the oceans at a faster rate than at any time in the last 300 million years. The sheer speed of change means we do not know how severe the consequences will be. As well as warming the planet, carbon dioxide seeps into the oceans and forms carbonic acid. As a result the water becomes more acidic. The pH is currently dropping by about 0.1 per century. This ocean acidification harms organisms such as corals that rely on dissolved carbonate to make their shells.
It also disrupts behaviour in some animals. Bärbel Hönisch of Columbia University in Palisades, New York, and colleagues used the chemical record preserved in rocks to gauge previous ocean acidification events. The best match for current changes was the Palaeocene-Eocene thermal maximum of 55 million years ago, when vast amounts of methane were released into the atmosphere causing rapid global warming, ocean acidification, and mass extinction. More From New Scientist Promoted Stories. Oceans' Salinity Changed Over Last Half-century. Ocean-Borne Microbes May Help Speed Warming. On their own, cyanobacteria are tiny photosynthetic organisms floating in the sea. But when they join forces, linking together into chains and then mats by the millions, they can become a threat. Before long, the bacteria change the color of the sea’s surface and even soften the wind-tossed chop. One study of cyanobacteria, also known as blue-green algae, although they are not algae, predicted that rising sea temperatures could help the already widespread creatures expand their territory by more than 10 percent.
Now researchers are asking whether mats of cyanobacteria might themselves affect local sea temperatures, thus creating a powerful feedback loop. Cyanobacteria are ubiquitous. They spew enough oxygen into the atmosphere to dictate the current mix of gases we breathe. This may be the first such study of algal blooms in the ocean, says aquatic microbiologist Jef Huisman of the University of Amsterdam, who has studied light absorption by cyanobacteria in lakes.
Gene Therapy Could Help Corals Survive Climate Change. Editor's note: Climate Query is a semi-weekly feature offered by Daily Climate, presenting short Q&A's with players large and small in the climate arena. Read others in the series at Kim Ritchie fell into coral research as an undergraduate, got a Ph.D. in genetics and was doing post-doctoral research in Panama when she lost her funding. With the ideal training for biotech, however, she slipped right into a startup. But when the company went bankrupt, she jumped back into research. Today she manages the microbiology program at Mote Marine Laboratory in Sarasota, Fla., a nonprofit research center dedicated to studying marine and estuarine ecosystems. Ritchie is taking a novel approach to reviving stressed coral reefs, looking at the role bacteria can play in coral health.
Why are reefs important? Coral reefs face at least three threats – pollution, overfishing and climate change. Any scary moments while diving? How Coral Bleaching Leads to Famine. For Tim McClanahan, a zoologist studying fisheries, what happened in Kenya during the spring of 1998 was a wake-up call. Between March and July of that year, a rare climatological double whammy sent ocean temperatures spiking 1 to 2 degrees Celsius above the normal range for spring and summer. An unusually intense El Niño weather pattern coincided with the warm phase of another cyclical area weather event.
This turned out to be a slow-motion disaster. Half the corals in the region bleached and died that year. Some had a 90 percent loss. "The bleaching and mortality event took about six months to fully unfold, but many of the reefs have not recovered even today -- 14 years after the event," said McClanahan, an employee of the Wildlife Conservation Society. He has spent more than 20 years working along Kenya's southeastern coast. It took four years before scientists could definitively show dramatic declines in three commonly caught species of food fish.
What Thawed the Last Ice Age? Arctic methane leaks threaten climate - environment - 22 April 2012. As Arctic sea ice breaks apart, massive amounts of methane could be released into the atmosphere from the cold waters beneath. High concentrations of the greenhouse gas have been recorded in the air above cracks in the ice. This could be evidence of yet another positive feedback on the warming climate – leading to even faster Arctic warming.
The Arctic is home to vast stores of methane – there are billions of tonnes of methane in permafrost alone. It is a potent greenhouse gas, so a major methane release would greatly accelerate climate change. The gas is found in icy crystals called hydrates beneath the shallow seas that flood some areas of the continental crust, as well as in permafrost. It is also being released from Arctic wetlands. But this doesn't explain why Eric Kort of the Jet Propulsion Laboratory in Pasadena, California, and his colleagues found patches of methane in remote regions of the Arctic Ocean, far from any of these known methane sources. Gassy ocean Hotter and hotter. El Nino Climate Pattern May Influence Disease Outbreaks Globally.
Certain disease outbreaks, including some of the worst pandemics of the 20th century, are linked to weather patterns in the Pacific Ocean, according to new research. Scientists said tracking these climate changes can help officials anticipate and plan for surges in illnesses. The El Niño-Southern Oscillation (ENSO) cycle causes ripples through the global climate, changing rainfall and air currents. These shifts, in turn, can cause disease carriers to interact in new ways, creating novel pathogens. Weather changes can also increase the number of people exposed to a disease, increasing the likelihood of an outbreak. El Niño is the warm phase of the ENSO, characterized by unusually high sea surface temperatures along the equator in the Pacific, lasting between nine months and two years, according to the National Oceanic and Atmospheric Administration. The temperature changes seem small -- usually 0.5 to 1 degree Celsius -- but they can alter rainfall patterns all over the world.
Melting sea ice could trigger colder winters - environment - 27 February 2012. Arctic Sea Emits Methane. Plankton under sea ice may disrupt Arctic food chain - environment - 07 June 2012. The water beneath a snow-covered expanse of ice 1 metre thick hardly seems like a good home for light-loving creatures. But microscopic phytoplankton, which rely on the sun for their nutrients and form the base of Arctic food webs, have managed to thrive under ice sheets that are thinning as the poles become warmer. The buried "bloom" of phytoplankton – the largest ever found underneath an ice shelf – was four times more concentrated than blooms found in the open ocean. Some say its discovery could mark the first major change in the Arctic ecosystem as a result of climate change. "We had no clue [they existed]," says Kevin Arrigo of Stanford University in Stanford, California, although he says researchers had found hints of blooms under the ice in the past.
Remote sensing technology, which monitors ocean life from space, cannot detect blooms through the ice. Arrigo and other researchers came across the bloom by accident on a cruise in Alaska's Chukchi Sea. It's important we try, though. Release of Arctic methane could accelerate warming - environment - 21 May 2012. Melting Arctic permafrost could put even more methane – a potent greenhouse gas – into the atmosphere than previously thought, with worrying implications for the pace of global warming. Many ice sheets that sit like caps over rock crevices trap natural seeps of methane; when they melt, the gas can quickly be released into the atmosphere in "burps". Geologists have long suspected that iced-over geological structures might entrap vast stores of ancient methane that seep from coal and gas deposits, although no one knows exactly how much is there.
These stores, along with deep-water stores and shallow (more recent) deposits of decaying plant material in frozen soil, might open as the Arctic warms, releasing vast amounts of methane. Then, as the climate warms, more methane seeps could open and warming could accelerate. Ancient gas The team estimate that Alaska is emitting 50 to 70 per cent more methane into the atmosphere than previously thought. More From New Scientist More from the web. Study Keeps Pace With Greenland Glaciers. Antarctica’s Ice Being Eaten Away From Below. Want to stay on top of all the space news? Follow @universetoday on Twitter Data collected from a NASA ice-watching satellite reveal that the vast ice shelves extending from the shores of western Antarctica are being eaten away from underneath by ocean currents, which have been growing warmer even faster than the air above.
The animation above shows the circulation of ocean currents around the western Antarctic ice shelves. The shelf thickness is indicated by the color; red is thicker (greater than 550 meters), while blue is thinner (less than 200 meters). Launched in January 2003, NASA’s ICESat (Ice, Cloud and land Elevation Satellite) studied the changing mass and thickness of Antarctica’s ice from its location in polar orbit. The 820-foot-wide crack in Antarctica's Pine Island Glacier, seen from DC-8 during Operation IceBridge (Credit: NASA/DMS) The study also found that Antarctica’s winds are shifting in response to climate change.
Read more on NASA’s news release here. About Jason Major. Big Antarctic Ice Sheet Appears Doomed. Antarctic Ice Sheet Collapse Recorded In Octopus DNA | Octopus Chronicles. Map of current land and ice separating the Weddell and Ross seas, courtesy of Wikimedia Commons/Wutsje/CIA Octopuses have made themselves at home in most of the world’s oceans—from the warmest of tropical seas to the deep, dark reaches around hydrothermal vents. Antarctic species, such as Turquet’s octopuses (Pareledone turqueti), even live slow, quiet lives near the South Pole. But these retiring creatures offer a rare opportunity to help understand how this extreme part of the Earth has changed in recent geologic times—and what climate change might bring there in the near future. Researchers can compare genetic patterns of current animal populations to look back in evolutionary time to estimate when populations of animals might have split off.
Research has suggested that this ice shelf has collapsed a number of times in the past—likely during the Pleistocene interglacial periods, most likely starting some 1.25 million years ago. Illustration courtesy of Ivan Phillipsen. Loss of Antarctic ice could trigger super-interglacial - environment - 21 June 2012. At least eight times in the last 2.8 million years, the Arctic experienced super-interglacials – periods in which summers there were 5 °C warmer than they are today.
Climate models cannot explain these unusually warm spells, but there could be an unexpected cause: the collapse of the West Antarctic ice sheet (WAIS), on the other side of the planet. The sheet could collapse again as the world warms, perhaps heralding super-interglacial number nine. The evidence for the super-interglacials comes from a sediment core drilled from the bed of Lake El'gygytgyn in north-east Russia by Martin Melles of the University of Köln in Germany, and his colleagues.
Toasty warm The Arctic ice sheets have been , as temperatures fell and rose. What triggered these super-interglacials? Melles ran into the same problem. He turned to sediment records from Antarctica for further clues. All around the world "What we see today is a dramatic decrease of the WAIS," Melles says. More From New Scientist More from the web. Rising Ocean Temperatures Prime Amazon Rainforest for Fire.
MOYOBAMBA, Peru – Karina Pinasco watched in dismay as flames on a hillside at the edge of town lit up the sky one night in October 2010. A farmer had intended to clear a few hectares of land to plant coffee bushes, but the fire – set during an unusually hot, dry spell – quickly got out of hand. Propelled by winds and high temperatures, it burned for 10 days, charring more than 250 acres of land. "We realized we weren't prepared," says Pinasco, a biologist who heads Amazónicos por la Amazonía, a local environmental organization. "The firefighters weren't trained. It was the rain that finally put it out.
" Scientists used to think the rainforest, especially in the western Amazon, was too wet to burn. Fires are a major source of carbon emissions in the Amazon, and scientists are beginning to worry that the region could become a net emitter, instead of a carbon sink. And as humans push further into an increasingly drier Amazon, the problem could worsen. Warming Ocean Current Might Create Coral Refuges. Global warming is expected to have devastating effects on coral reefs, but recent research points to a few exceptions. Warming in the equatorial Pacific may actually create refuges for corals around a handful of islands, even as it bleaches, or kills, corals elsewhere, suggests new research that predicts increased upwelling of cold, nutrient-rich water in these places. "These little islands in the middle of the ocean can counteract global trends and have a big impact on their own future, which I think is a beautiful concept," said study researcher Kristopher Karnauskas, a Woods Hole Oceanographic Institution scientist, in a press release issued by the institution.
If predictions made by Karnauskas and colleague Anne Cohen are accurate, warming around the Gilbert Islands will be slower than elsewhere, giving the corals and their symbiotic algae a better chance to adapt. Corals are animals that host tiny plants, or algae, that feed them using photosynthesis. Warm Currents Threaten to Expand Antarctic Melting. Another section of the vast Antarctic ice sheet is threatened by warm ocean waters, scientists reported yesterday. Researchers have watched as warm, deep currents have carved away at the underside of ice shelves on the western Antarctic coast, accelerating ice loss by eroding the floating ice tongues that help slow glaciers' flow to the sea. Now a pair of new studies suggest that, by the end of the century, the same process could begin thawing a portion of the vast Antarctic ice sheet that researchers considered to be relatively stable. The Filchner-Ronne Ice Shelf covers more than 174,000 square miles in the Weddell Sea on the eastern side of the Antarctica Peninsula.
The new research suggests that region, which has not experienced much ice loss so far, could begin a period of rapid change as rising air temperatures thin the region's sea ice. The grounding line, where the ice shelf leaves bedrock and begins floating on water, lies just beyond the edge of the basin.