by Deep Green Resistance News Service | Apr 22, 2012 | Climate Change
By Michael Marshall / NewScientist
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.
The team found the patches during five flights over the Arctic Ocean between 2009 and 2010, as part of a project to systematically map greenhouse gas levels in the atmosphere.
Kort estimates that, in the methane-rich regions, about 2 milligrams of the gas were being released per square metre of ocean every day. Some of the patches were close to the oil and gas plants in Prudhoe Bay, Alaska, but prevailing wind directions make these plants an unlikely source of the release.
Gassy ocean
So where does the gas come from? Since the 1970s, scientists have known that ocean surface waters are rich in methane. It seems to be made by marine bacteria trying to survive in waters that don’t have many nutrients in the form of nitrates. “This source appears to be a likely candidate to explain what we observed,” Kort says.
Water in the Arctic Ocean doesn’t mix well, so the water near the surface tends to remain there. Consequently, the methane ends up trapped near the surface. In other oceans, it would get broken down through reaction with oxygen or consumed by methanotrophic bacteria, but the cold weather helps to preserve it.
Kort saw methane releases close to cracks in the sea ice, or in places where the ice had broken up. This could be because methane only escapes from agitated water, says Ellen Damm of the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany. This agitation is most likely to occur when autumn sets in and ice crystals start forming in the water, creating turbulence.
Hotter and hotter
The findings will need to be replicated, says Euan Nisbet, an earth scientist at Royal Holloway, University of London. But if the leak is widespread across the Arctic, this mechanism could prove to be a significant source of greenhouse gas.
“We know the Arctic is warming very fast indeed,” Nisbet says. And as the warming climate leads to more breaks in the sea ice, more ice-surrounded patches of open water will be able to release their methane, further accelerating global warming.
The question now is: how significant will this new effect on warming be? “It might be small,” Nisbet says, “or it could be another serious problem.”
From NewScientist: http://www.newscientist.com/article/dn21733-arctic-methane-leaks-threaten-climate.html
by Deep Green Resistance News Service | Apr 14, 2012 | Biodiversity & Habitat Destruction, Climate Change, Lobbying
By ENews Park Forest
Without help, more than 50 coral species in U.S. waters are likely to go extinct by the end the century, primarily because of ocean warming, disease and ocean acidification, a government report said today. The National Marine Fisheries Service released a status review of 82 corals that are being considered for protections under the Endangered Species Act following a 2009 petition by the Center for Biological Diversity.
“Coral reefs are at real risk of vanishing in our lifetimes if we don’t act fast,” said Miyoko Sakashita, oceans director with the Center for Biological Diversity. “The Endangered Species Act has saved hundreds of species from extinction, but these corals will only benefit if they’re actually protected.”
Of the 82 corals, 56 are likely to be extinct before 2100, the report said. The corals are in U.S. waters, ranging from Florida and Hawaii to U.S. territories in the Caribbean and Pacific. The report notes that the seven Florida and Caribbean corals are extremely likely to go extinct, and five of those corals ranked in the top seven of most imperiled overall. Today’s report makes no recommendation about whether the corals may warrant protection under the Endangered Species Act.
According to the status review, “The combined direct and indirect effects of rising temperature, including increased incidence of disease and ocean acidification, both resulting primarily from anthropogenic increases in atmospheric CO2, are likely to represent the greatest risks of extinction to all or most of the candidate coral species over the next century.”
Coral reefs are home to 25 percent of marine life and play a vital function in ocean ecosystems. Already one-third of the world’s coral reefs have been destroyed, and scientists warn that by mid-century most corals will be in inhospitable waters that are too warm or acidic. Since the 1990s, coral growth has grown sluggish in some areas due to ocean acidification, and mass bleaching events are increasingly frequent.
“I’m eager to show my kids the wonder of a coral reef. I worry that if we wait too long, they’ll never get to experience a healthy reef teeming with colorful life,” said Sakashita. “These delicate corals need help, first with federal protections, and then with dramatic reductions in carbon dioxide pollution.”
The Fisheries Service is accepting comments on the coral status review and management reports until July 31, 2012. Pursuant to a settlement agreement with the Center, the Fisheries Service will make a determination on whether listing is warranted for the corals by Dec. 1, 2012. In 2006, the Center secured protection for staghorn and elkhorn corals, making them the first — and so far, only — corals listed under the Endangered Species Act.
From ENews Park Forest
by Deep Green Resistance News Service | Apr 12, 2012 | Biodiversity & Habitat Destruction, Climate Change
By Craig Welch / The Seattle Times
Researchers said Wednesday they have conclusive evidence that ocean acidification is at least partly responsible for killing oysters on the West Coast.
It’s been eight years since baby oysters started dying by the billions at an Oregon hatchery and in Washington’s Willapa Bay.
In 2009, top scientists drew global attention when they said evidence suggested the culprit might be changing ocean chemistry from the same greenhouse gases that contribute to global warming. They just couldn’t prove it — until now.
Researchers said Wednesday they can definitively show that ocean acidification is at least partly responsible for massive oyster die-offs at the hatchery in Netarts Bay, Ore.
It’s the first concrete finding in North America that carbon dioxide being taken up by the oceans already is helping kill marine species.
“This is the smoking gun for oyster larvae,” said Richard Feely, an oceanographer and leading marine-chemistry researcher with the National Oceanic and Atmospheric Administration in Seattle and one of the paper’s authors.
Said Alan Barton, another of the paper’s authors: “It’s now an incontrovertible fact that ocean chemistry is affecting our larvae.”
In a paper published this week in the journal Limnology and Oceanography, the scientists studied the water that gets pumped from the Pacific Ocean into the Whiskey Creek Hatchery, which supplies baby shellfish for most of the West Coast’s $110 million-a-year oyster industry.
Here’s why: Since 2005, wild oysters along the Washington coast and at the hatchery had been dying inexplicably in their larval stages. At first the suspect was a bacterial disease, but hatchery workers soon noticed that the die-offs only occurred after high winds drew water from the ocean deep.
Unlike the complex mechanics of climate change, ocean acidification is just basic chemistry. Scientists long had predicted that as carbon dioxide from fossil fuels gets taken up by the seas, ocean waters — typically slightly alkaline — would slide closer to the acidic side of the pH scale. They just expected it would take 50 to 100 years.
But Feely and other top researchers in 2007 and 2008 had discovered that the pH of marine waters along the West Coast had dropped decades earlier than expected.
Read more from The Seattle Times
by Deep Green Resistance News Service | Mar 27, 2012 | Climate Change
By Nina Chestney / Reuters
The world is close to reaching tipping points that will make it irreversibly hotter, making this decade critical in efforts to contain global warming, scientists warned on Monday.
Scientific estimates differ but the world’s temperature looks set to rise by six degrees Celsius by 2100 if greenhouse gas emissions are allowed to rise uncontrollably.
As emissions grow, scientists say the world is close to reaching thresholds beyond which the effects on the global climate will be irreversible, such as the melting of polar ice sheets and loss of rainforests.
“This is the critical decade. If we don’t get the curves turned around this decade we will cross those lines,” said Will Steffen, executive director of the Australian National University’s climate change institute, speaking at a conference in London.
Despite this sense of urgency, a new global climate treaty forcing the world’s biggest polluters, such as the United States and China, to curb emissions will only be agreed on by 2015 – to enter into force in 2020.
“We are on the cusp of some big changes,” said Steffen. “We can … cap temperature rise at two degrees, or cross the threshold beyond which the system shifts to a much hotter state.”
TIPPING POINTS
For ice sheets – huge refrigerators that slow down the warming of the planet – the tipping point has probably already been passed, Steffen said. The West Antarctic ice sheet has shrunk over the last decade and the Greenland ice sheet has lost around 200 cubic km (48 cubic miles) a year since the 1990s.
Most climate estimates agree the Amazon rainforest will get drier as the planet warms. Mass tree deaths caused by drought have raised fears it is on the verge of a tipping point, when it will stop absorbing emissions and add to them instead.
Around 1.6 billion tonnes of carbon were lost in 2005 from the rainforest and 2.2 billion tonnes in 2010, which has undone about 10 years of carbon sink activity, Steffen said.
One of the most worrying and unknown thresholds is the Siberian permafrost, which stores frozen carbon in the soil away from the atmosphere.
“There is about 1,600 billion tonnes of carbon there – about twice the amount in the atmosphere today – and the northern high latitudes are experiencing the most severe temperature change of any part of the planet,” he said.
In a worst case scenario, 30 to 63 billion tonnes of carbon a year could be released by 2040, rising to 232 to 380 billion tonnes by 2100. This compares to around 10 billion tonnes of CO2 released by fossil fuel use each year.
Increased CO2 in the atmosphere has also turned oceans more acidic as they absorb it. In the past 200 years, ocean acidification has happened at a speed not seen for around 60 million years, said Carol Turley at Plymouth Marine Laboratory.
From Scientific American:
by Deep Green Resistance News Service | Mar 25, 2012 | Climate Change
By Agence France-Presse
Climate change has accelerated in the past decade, the UN weather agency said Friday, releasing data showing that 2001 to 2010 was the warmest decade on record.
The 10-year period was also marked by extreme levels of rain or snowfall, leading to significant flooding on all continents, while droughts affected parts of East Africa and North America.
“The decade 2001-2010 was the warmest since records began in 1850, with global land and sea surface temperatures estimated at 0.46 degrees Celsius above the long term average of 14.0 degrees Celsius (57.2 degrees Fahrenheit),” said the World Meteorological Organisation.
Nine of the 10 years also counted among the 10 warmest on record, it added, noting that “climate change accelerated” during the first decade of the 21st century.
The trend continued in 2011, which was the warmest year on record despite La Nina — a weather pattern which has a cooling effect.
The average temperature in 2011 was 0.40 degrees Celsius above the long term average, said the WMO.
“This 2011 annual assessment confirms the findings of the previous WMO annual statements that climate change is happening now and is not some distant future threat,” said WMO Secretary-General Michel Jarraud.
“The world is warming because of human activities and this is resulting in far-reaching and potentially irreversible impacts on our Earth, atmosphere and oceans,” he added.
The UN weather agency noted that during the decade, “numerous weather and climate extremes affected almost every part of the globe with flooding, droughts, cyclones, heat waves and cold waves.”
Historical floods hit Eastern Europe in 2001 and 2005, Africa in 2008, Asia and Australia in 2010.Global precipitation — including rain or snow — reached the second highest average since 1901. The highest average was recorded for the decade 1951-1960.
Meanwhile for the North Atlantic basin, the 10 years marked the highest level of tropical cyclone activity, including Hurricane Katrina which struck the United States in 2005 and Cyclone Nargis which hit Myanmar in 2008.
From PhysOrg: http://www.physorg.com/news/2012-03-warmest-decade-wmo.html
