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  • richardmitnick 11:03 am on March 3, 2015 Permalink | Reply
    Tags: ABC News, Climate Change,   

    From ABC News: “The Big Melt: Antarctica’s Retreating Ice May Re-Shape Earth” 

    ABC News bloc

    ABC News

    Feb 27, 2015,
    Luis Andres Henao
    Seth Borenstein

    1
    In this Jan. 22, 2015 photo, a zodiac carrying a team of international scientists heads to Chile’s station Bernardo O’Higgins, Antarctica. Water is eating away at the Antarctic ice, melting it where it hits the oceans. As the ice sheets slowly thaw, water pours into the sea, 130 billion tons of ice (118 billion metric tons) per year for the past decade, according to NASA satellite calculations. (AP Photo/Natacha Pisarenko)

    From the ground in this extreme northern part of Antarctica, spectacularly white and blinding ice seems to extend forever. What can’t be seen is the battle raging thousands of feet (hundreds of meters) below to re-shape Earth.

    Water is eating away at the Antarctic ice, melting it where it hits the oceans. As the ice sheets slowly thaw, water pours into the sea — 130 billion tons of ice (118 billion metric tons) per year for the past decade, according to NASA satellite calculations. That’s the weight of more than 356,000 Empire State Buildings, enough ice melt to fill more than 1.3 million Olympic swimming pools. And the melting is accelerating.

    In the worst case scenario, Antarctica’s melt could push sea levels up 10 feet (3 meters) worldwide in a century or two, recurving heavily populated coastlines.

    Parts of Antarctica are melting so rapidly it has become “ground zero of global climate change without a doubt,” said Harvard geophysicist Jerry Mitrovica.

    Here on the Antarctic peninsula, where the continent is warming the fastest because the land sticks out in the warmer ocean, 49 billion tons of ice (nearly 45 billion metric tons) are lost each year, according to NASA. The water warms from below, causing the ice to retreat on to land, and then the warmer air takes over. Temperatures rose 5.4 degrees Fahrenheit (3 degrees Celsius) in the last half century, much faster than Earth’s average, said Ricardo Jana, a glaciologist for the Chilean Antarctic Institute.

    As chinstrap penguins waddled behind him, Peter Convey of the British Antarctic Survey reflected on changes he could see on Robert Island, a small-scale example and perhaps early warning signal of what’s happening to the peninsula and rest of the continent as a whole.

    “I was last here 10 years ago,” Convey said during a rare sunny day on the island, with temperatures just above freezing. “And if you compare what I saw back then to now, the basic difference due to warming is that the permanent patches of snow and ice are smaller. They’re still there behind me, but they’re smaller than they were.”

    Robert Island hits all the senses: the stomach-turning smell of penguin poop; soft moss that invites the rare visitor to lie down, as if on a water bed; brown mud, akin to stepping in gooey chocolate. Patches of the moss, which alternates from fluorescent green to rust red, have grown large enough to be football fields. Though 97 percent of the Antarctic Peninsula is still covered with ice, entire valleys are now free of it, ice is thinner elsewhere and glaciers have retreated, Convey said.

    Dressed in a big red parka and sky blue hat, plant biologist Angelica Casanova has to take her gloves off to collect samples, leaving her hands bluish purple from the cold. Casanova says she can’t help but notice the changes since she began coming to the island in 1995. Increasingly, plants are taking root in the earth and stone deposited by retreating glaciers, she says.

    “It’s interesting because the vegetation in some way responds positively. It grows more,” she said, a few steps from a sleeping Weddell seal. “What is regrettable is that all the scientific information that we’re seeing says there’s been a lot of glacier retreat and that worries us.”

    Just last month, scientists noticed in satellite images that a giant crack in an ice shelf on the peninsula called Larsen C had grown by about 12 miles (20 kilometers) in 2014. Ominously, the split broke through a type of ice band that usually stops such cracks. If it keeps going, it could cause the breaking off of a giant iceberg somewhere between the size of Rhode Island and Delaware, about 1,700 to 2,500 square miles (4,600 to 6,400 square kilometers), said British Antarctic Survey scientist Paul Holland. And there’s a small chance it could cause the entire Scotland-sized Larsen C ice shelf to collapse like its sister shelf, Larsen B, did in a dramatic way in 2002.

    A few years back, scientists figured Antarctica as a whole was in balance, neither gaining nor losing ice. Experts worried more about Greenland; it was easier to get to and more noticeable, but once they got a better look at the bottom of the world, the focus of their fears shifted. Now scientists in two different studies use the words “irreversible” and “unstoppable” to talk about the melting in West Antarctica. Ice is gaining in East Antarctica, where the air and water are cooler, but not nearly as much as it is melting to the west.

    “Before Antarctica was much of a wild card,” said University of Washington ice scientist Ian Joughin. “Now I would say it’s less of a wild card and more scary than we thought before.”

    Over at NASA, ice scientist Eric Rignot said the melting “is going way faster than anyone had thought. It’s kind of a red flag.”

    What’s happening is simple physics. Warm water eats away at the ice from underneath. Then more ice is exposed to the water, and it too melts. Finally, the ice above the water collapses into the water and melts.

    Climate change has shifted the wind pattern around the continent, pushing warmer water farther north against and below the western ice sheet and the peninsula. The warm, more northerly water replaces the cooler water that had been there. It’s only a couple degrees Fahrenheit warmer than the water that used to be there, but that makes a huge difference in melting, scientists said.

    The world’s fate hangs on the question of how fast the ice melts.

    At its current rate, the rise of the world’s oceans from Antarctica’s ice melt would be barely noticeable, about one-third of a millimeter a year. The oceans are that vast.

    But if all the West Antarctic ice sheet that’s connected to water melts unstoppably, as several experts predict, there will not be time to prepare. Scientists estimate it will take anywhere from 200 to 1,000 years to melt enough ice to raise seas by 10 feet, maybe only 100 years in a worst case scenario. If that plays out, developed coastal cities such as New York and Guangzhou could face up to $1 trillion a year in flood damage within a few decades and countless other population centers will be vulnerable.

    “Changing the climate of the Earth or thinning glaciers is fine as long as you don’t do it too fast. And right now we are doing it as fast as we can. It’s not good,” said Rignot, of NASA. “We have to stop it; or we have to slow it down as best as we can. ”

    See the full article here.

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  • richardmitnick 4:04 am on February 24, 2015 Permalink | Reply
    Tags: , Climate Change, ,   

    From Huff Post: “Here’s What Will Happen To New York City If The World’s Ice Sheets Melt” 

    Huffington Post
    The Huffington Post

    02/23/2015
    Christopher Mathias

    1

    A disconcerting report released last week revealed that New York City could see a 6-foot rise in sea levels by the end of this century. It would make nearly half a million New Yorkers vulnerable to flooding, and waterfront properties would be virtually uninhabitable.

    But what if climate change continues unabated for even longer? What will New York City look like if, say, both the Antarctic and Greenland ice sheets melt completely, raising sea levels an estimated 260 feet?

    Urban planner and cartographer Jeffrey Linn used computerized mapping to make a GIF demonstrating just that. Watch the city’s five boroughs disappear, with only the lofty heights of New Jersey’s Pallisades left as an island:

    2

    Linn, who posted the GIF on his blog Spatialities, told The Huffington Post he wanted to show people what the city would look like after “the terminal point for ice caps melting,” which some scientists estimate could happen in 1,000 to 10,000 years.

    “What would the world around me look like, where I live, if in thousands of years, this is supposed to happen?” Linn said he wondered.

    Linn also made this mesmerizing map of New York City after only 100 feet of sea level rise. The city’s neighborhoods and parks are cleverly rechristened with more nautical nomenclatures: Central Park is Central Shark, Bushwick is Flushwick, the West Village is Wet Village, and so on:

    3

    He’s made similarly alarming maps for his hometown of Seattle, as well as London and Montreal, among other cities.

    The polar ice caps are melting at an alarming rate, as manmade greenhouse gas emissions continue to trap the sun’s heat. Here, for example, is a 2012 video showing a lower Manhattan-sized piece of ice breaking off from the Greenland ice sheet:

    See the full article here.

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  • richardmitnick 4:15 am on February 18, 2015 Permalink | Reply
    Tags: , Climate Change,   

    From Rutgers: “Climate Change Driving Brutal Winter?” 

    Rutgers University
    Rutgers University

    February 18, 2015
    Kirk Moore

    1

    Prolonged cold snaps on the East Coast, California drought and frozen mornings in the South all have something in common – the atmospheric jet stream which transports weather systems that’s taken to meandering all over North America.

    Rutgers University climate scientist Jennifer Francis and colleagues link that wavy jet stream to a warming Arctic, where climate changes near the top of the world are happening faster than in Earth’s middle latitudes.

    A new study from Francis and University of Wisconsin-Madison scientist Stephen Vavrus, published in IOPscience, backs up that theory, with evidence linking regional and seasonal conditions in the Arctic to deeper north-south jet stream waves which will lead to more extreme weather across the country.

    “The real story is how persistent the pattern has been. It’s been this way nearly continually since December 2013…Warm in the west, cold in the east,” Francis said. “We think with the warming Arctic these types of very wavy patterns, although probably not in the same locations, will happen more often in the future.”

    This research has been controversial since the Hurricane Sandy disaster, when the wavy jet stream steered the storm on its sharp left turn and smack into the Jersey Shore. Francis and other researchers say the jet stream’s configuration was a key ingredient in the monster storm.

    Very wavy jet-stream patterns have been occurring more often since the 1990s, Francis says, and are now affecting weather around the northern hemisphere. This mid-February cold snap, for example, that has left millions of people waking up to below-zero and single-digit temperatures, might not be as deep as some southward dips, called troughs, in the jet stream. But the overall pattern has been around for weeks, and is also responsible for Boston’s record snowfall this winter and the worsening drought in western states.

    In contrast, an opposite pattern in winter 2012 led to more than 3,000 high winter temperature records being broken in the eastern U.S., Francis notes.

    “California is still dealing with this record-breaking drought, and Alaska is having one of its warmest winters on record,” Francis said.

    In Florida, orange growers have not had to deal with freezing temperatures for the past two years. But they are looking at their smallest harvest on record because of citrus disease and watching the southward cold outbreaks closely. “We’ve been fortunate that those jet streams have not reached into our citrus production areas,” said Andrew Meadows, a spokesman for Florida Citrus Mutual, the industry’s biggest trade group.

    On the West Coast, the Pacific Ocean water temperatures off California are much warmer than normal, holding at uncanny 64- to 65-degree levels this winter, according to Mike Conroy of West Coast Fisheries Consultants, who works with commercial fishermen still catching bluefin tuna on the Cortes Bank 100 miles off San Diego.

    2
    Rutgers University climate scientist Jennifer Francis

    Francis says these conditions make sense because water temperature trends in the eastern Pacific have reversed from the past decade and could be contributing to California’s warmer and drier weather as the jet stream takes an unusually large swing to the north.

    The phenomenon called Arctic amplification – defined as the enhanced sensitivity of the Arctic region to warming compared to lower latitudes – is changing large-scale upper level flows in the atmosphere, the paper suggests. Looking back at records dating to the late 1940s, it is evident that Arctic amplification of global warming is now continuing through all four seasons of the year, according to Francis and Vavrus.

    One challenge addressed by the new study is measuring the extent and strength of those jet stream waves, Vavrus said.

    While using a traditional measure of surface air temperature changes between Arctic regions and lower latitudes, Francis and Vavrus also present an alternative measure of the thickness of temperature layers higher in the atmosphere.

    Even scientists who are skeptical of the findings say it’s a good effort to resolve the problem of differentiating real changes in the jet stream’s behavior from random noise. This is an issue inherent in climate research – teasing out real long-term climate change from mere year-to-year variability of weather.

    Francis and Vavrus acknowledge criticism that their work is looking at relatively recent years since Arctic amplification emerged as a clear signal. Still, the researchers say there is no mistaking the trend since the 1990s: the Arctic probably hasn’t been this warm since the last major inter-glacial period 125,000 years ago.

    Back then, Francis said, the Earth was several degrees warmer than now and sea levels were several meters higher. “The recent changes we’ve seen are clearly linked to increasing greenhouse gases, and there’s no sign of abatement in our use of fossil fuels. This does not bode well for impacts of extreme weather and the ecosystem as a whole,” she said.

    “The biggest challenge in our research,” Francis said. “Is that rapid Arctic warming started very recently, so detecting a clear atmospheric response and linking it to a particular cause may take another decade. In the meantime, Mother Nature seems to be acting out.”

    See the full article here.

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    Rutgers, The State University of New Jersey, is a leading national research university and the state’s preeminent, comprehensive public institution of higher education. Rutgers is dedicated to teaching that meets the highest standards of excellence; to conducting research that breaks new ground; and to providing services, solutions, and clinical care that help individuals and the local, national, and global communities where they live.

    Founded in 1766, Rutgers teaches across the full educational spectrum: preschool to precollege; undergraduate to graduate; postdoctoral fellowships to residencies; and continuing education for professional and personal advancement.

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  • richardmitnick 6:47 pm on February 9, 2015 Permalink | Reply
    Tags: , Climate Change, ,   

    From New Scientist: “Melting ice spells volcanic trouble” 

    NewScientist

    New Scientist

    05 February 2015
    Fred Pearce

    1
    Melting glaciers could lead to volcanic eruptions (Image: Image Broker/REX)

    Melting ice is causing the land to rise up in Iceland – and perhaps elsewhere. The result, judging by new findings on the floor of the Southern Ocean, could be a dramatic surge in volcanic eruptions.

    Last week, researchers at the University of Arizona in Tucson showed that a recent dramatic uplift of the Earth’s crust in parts of Iceland coincided with the rapid melting of nearby glaciers.

    Kathleen Compton’s team used data from GPS receivers that have been attached to rocks since 1995 to show that some parts of south-central Iceland, where five of the country’s largest glaciers are melting fast, have been rising by around 3.5 centimetres a year. Away from the glaciers, the rates of land rise were much lower.

    Their explanation is that the disappearance of the ice is relieving pressure on rocks beneath and allowing them to spring up.

    Rapid rebound

    It has long been known that the Earth’s crust falls and rises as ice caps grow and melt. But the speed of the rebound is surprising, says Compton.

    Richard Katz of the University of Oxford finds the discovery “very exciting”. “The measurements show that there is a response even at a very short time-scale of 30 years,” he says.

    The land uplift could be handy to protect some coastal areas from rising sea levels as the melting ice flows into the oceans. But there is a growing fear among geologists that climate-induced changes to water and ice levels could trigger more dangerous events, such as volcanic eruptions.

    The evidence is mostly from the past. For instance, during the last great melt 12,000 years ago, volcanic activity on Iceland was up to 50 times greater than the activity observed over the past century, says Bill McGuire, a volcanologist at University College London. Iceland has suffered three major volcanic eruptions in the past five years – although no one has shown a certain link with climate change.

    Seabed clue

    And today, fresh evidence of climatic cues for volcanic eruptions emerges from an analysis of thousands of kilometres of ridges on the floor of the Southern Ocean. The ridges were created by huge eruptions.

    Through detailed analysis of the topography of the seabed, John Crowley of the University of Oxford shows that the eruptions coincided with phases of orbital wobbles known as Milankovitch cycles, which trigger ice ages.

    He concludes that glaciations caused the increase in eruptions. By locking up much of the world’s water in ice sheets on land, they lowered sea levels and so reduced the ocean’s pressure on the seabed enough to allow magma to escape from the Earth’s mantle. “Our work reinforces the link between climate change and volcanism,” says Katz, a co-author of the Crowley paper.

    So it seems that glaciation can trigger submarine eruptions, while deglaciation may lead to magma outflows on land.

    “Both these studies reinforce the idea that the wholesale redistribution of water that accompanies major climate change elicits a significant response from the solid earth in the form of potentially hazardous phenomena such as earthquakes and volcanic eruptions,” says McGuire. “We saw this very dramatically at the end of the last ice age, and we are seeing it again today in Iceland and elsewhere.”

    See the full article here.

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  • richardmitnick 1:29 pm on December 24, 2014 Permalink | Reply
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    From AAAS: “China confirms its southern glaciers are disappearing” 

    AAAS

    AAAS

    22 December 2014
    Christina Larson

    Glaciers in China that are a critical source of water for drinking and irrigation in India are receding fast, according to a new comprehensive inventory. In the short term, retreating glaciers may release greater meltwater, “but it will be exhausted when glaciers disappear under a continuous warming,” says Liu Shiyin, who led the survey for the Cold and Arid Regions Environmental and Engineering Research Institute in Lanzhou.

    f
    Midui Glacier in Tibet (Jan Reurink/Wikimedia Commons (CC BY 2.0))

    In 2002, Chinese scientists released the first full inventory of the country’s glaciers, the largest glacial area outside of Antarctica and Greenland. The data came from topographical maps and aerial photographs of western China’s Tibet and Xinjiang regions taken from the 1950s through the 1980s. That record showed a total glacial area of 59,425 square kilometers. The Second Glacier Inventory of China, unveiled here last week, is derived from high-resolution satellite images taken between 2006 and 2010. The data set is freely available online.

    Liu and his colleagues calculated China’s total glacial area to be 51,840 square kilometers—13% less than in 2002. That figure is somewhat uncertain because the previous inventory used coarser resolution images that may have mistaken extensive snow cover for permanent ice, says Raymond Bradley, director of the Climate System Research Center at the University of Massachusetts, Amherst, who was not involved in the project.

    Methodological quibbles aside, the latest inventory flags a marked retreat of glaciers in the southern and eastern fringes of the Tibetan Plateau. “We found the fastest shrinking glaciers are those in the central upper reach of the Brahmaputra River, between the central north Himalaya [and] the source region of the tributary of the Indus River,” Liu says.

    Matthias Huss, a glaciologist at the University of Fribourg in Switzerland, applauds the openness in sharing data, which hasn’t always been the norm in China. “It is highly useful that the colleagues from China have made their data set available to the community. It will feed directly into global efforts to compile a worldwide glacier inventory and is a major improvement,” he says. “It will, for example, greatly support the effort of global glacier modeling to improve our understanding of glaciers’ response to climate change.”

    See the full article here.

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  • richardmitnick 8:40 am on September 16, 2014 Permalink | Reply
    Tags: , , Climate Change   

    From astrobio.net: “Microscopic Diamonds Suggest Cosmic Impact Responsible for Major Period of Climate Change” 

    Astrobiology Magazine

    Astrobiology Magazine

    Sep 16, 2014
    From University of Chicago
    Emily Murphy / University of Chicago Press / emurphy@press.uchicago.edu

    A new study published in The Journal of Geology provides support for the theory that a cosmic impact event over North America some 13,000 years ago caused a major period of climate change known as the Younger Dryas stadial, or “Big Freeze.”

    freeze
    Credit: iStockphoto/Trevor Hunt

    Around 12,800 years ago, a sudden, catastrophic event plunged much of the Earth into a period of cold climatic conditions and drought. This drastic climate change—the Younger Dryas—coincided with the extinction of Pleistocene megafauna, such as the saber-tooth cats and the mastodon, and resulted in major declines in prehistoric human populations, including the termination of the Clovis culture.

    With limited evidence, several rival theories have been proposed about the event that sparked this period, such as a collapse of the North American ice sheets, a major volcanic eruption, or a solar flare.

    However, in a study published in The Journal of Geology, an international group of scientists analyzing existing and new evidence have determined a cosmic impact event, such as a comet or meteorite, to be the only plausible hypothesis to explain all the unusual occurrences at the onset of the Younger Dryas period.

    Researchers from 21 universities in 6 countries believe the key to the mystery of the Big Freeze lies in nanodiamonds scattered across Europe, North America, and portions of South America, in a 50-million-square-kilometer area known as the Younger Dryas Boundary (YDB) field.

    Microscopic nanodiamonds, melt-glass, carbon spherules, and other high-temperature materials are found in abundance throughout the YDB field, in a thin layer located only meters from the Earth’s surface. Because these materials formed at temperatures in excess of 2200 degrees Celsius, the fact they are present together so near to the surface suggests they were likely created by a major extraterrestrial impact event.

    In addition to providing support for the cosmic impact event hypothesis, the study also offers evidence to reject alternate hypotheses for the formation of the YDB nanodiamonds, such as by wildfires, volcanism, or meteoric flux.

    The team’s findings serve to settle the debate about the presence of nanodiamonds in the YDB field and challenge existing paradigms across multiple disciplines, including impact dynamics, archaeology, paleontology, limnology, and palynology.

    See the full article here.

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  • richardmitnick 7:31 am on August 26, 2014 Permalink | Reply
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    From M.I.T.- “Study: Cutting emissions pays for itself” 


    MIT News

    August 24, 2014
    Audrey Resutek | Joint Program on the Science and Policy of Global Change

    Lower rates of asthma and other health problems are frequently cited as benefits of policies aimed at cutting carbon emissions from sources like power plants and vehicles, because these policies also lead to reductions in other harmful types of air pollution.

    But just how large are the health benefits of cleaner air in comparison to the costs of reducing carbon emissions? MIT researchers looked at three policies achieving the same reductions in the United States, and found that the savings on health care spending and other costs related to illness can be big — in some cases, more than 10 times the cost of policy implementation.

    scales
    Illustration: Christine Daniloff/MIT

    “Carbon-reduction policies significantly improve air quality,” says Noelle Selin, an assistant professor of engineering systems and atmospheric chemistry at MIT, and co-author of a study published today in Nature Climate Change. “In fact, policies aimed at cutting carbon emissions improve air quality by a similar amount as policies specifically targeting air pollution.”

    Selin and colleagues compared the health benefits to the economic costs of three climate policies: a clean-energy standard, a transportation policy, and a cap-and-trade program. The three were designed to resemble proposed U.S. climate policies, with the clean-energy standard requiring emissions reductions from power plants similar to those proposed in the Environmental Protection Agency’s Clean Power Plan.

    Health savings constant across policies

    The researchers found that savings from avoided health problems could recoup 26 percent of the cost to implement a transportation policy, but up to to 10.5 times the cost of implementing a cap-and-trade program. The difference depended largely on the costs of the policies, as the savings — in the form of avoided medical care and saved sick days — remained roughly constant: Policies aimed at specific sources of air pollution, such as power plants and vehicles, did not lead to substantially larger benefits than cheaper policies, such as a cap-and-trade approach.

    Savings from health benefits dwarf the estimated $14 billion cost of a cap-and-trade program. At the other end of the spectrum, a transportation policy with rigid fuel-economy requirements is the most expensive policy, costing more than $1 trillion in 2006 dollars, with health benefits recouping only a quarter of those costs. The price tag of a clean energy standard fell between the costs of the two other policies, with associated health benefits just edging out costs, at $247 billion versus $208 billion.

    “If cost-benefit analyses of climate policies don’t include the significant health benefits from healthier air, they dramatically underestimate the benefits of these policies,” says lead author Tammy Thompson, now at Colorado State University, who conducted the research as a postdoc in Selin’s group.

    Most detailed assessment to date

    The study is the most detailed assessment to date of the interwoven effects of climate policy on the economy, air pollution, and the cost of health problems related to air pollution. The MIT group paid especially close attention to how changes in emissions caused by policy translate into improvements in local and regional air quality, using comprehensive models of both the economy and the atmosphere.

    In addition to carbon dioxide, burning fossil fuels releases a host of other chemicals into the atmosphere. Some of these substances interact to form ground-level ozone, as well as fine particulate matter. The researchers modeled where and when these chemical reactions occurred, and where the resulting pollutants ended up — in cities where many people would come into contact with them, or in less populated areas.

    The researchers projected the health effects of ground-level ozone and fine particulate matter, two of the biggest health offenders related to fossil-fuel emissions. Both pollutants can cause asthma attacks and heart and lung disease, and can lead to premature death.

    In 2011, 231 counties in the U.S. exceeded the EPA’s regulatory standards for ozone, the main component of smog. Standards for fine particulate matter — airborne particles small enough to be inhaled deep into the lungs and even absorbed into the bloodstream — were exceeded in 118 counties.

    While cutting carbon dioxide from current levels in the U.S. will result in savings from better air quality, pollution-related benefits decline as carbon policies become more stringent. Selin cautions that after a certain point, most of the health benefits have already been reaped, and additional emissions reductions won’t translate into greater improvements.

    “While air-pollution benefits can help motivate carbon policies today, these carbon policies are just the first step,” Selin says. “To manage climate change, we’ll have to make carbon cuts that go beyond the initial reductions that lead to the largest air-pollution benefits.”

    The study shows that climate policies can also have significant local benefits not related to their impact on climate, says Gregory Nemet, a professor of public affairs and environmental studies at the University of Wisconsin at Madison who was not involved in the study.

    “A particularly notable aspect of this study is that even though several recent studies have shown large co-benefits, this study finds large co-benefits in the U.S., where air quality is assumed to be high relative to other countries,” Nemet says. “Now that states are on the hook to come up with plans to meet federal emissions targets by 2016, you can bet they will take a close look at these results.”

    This research was supported by funding from the EPA’s Science to Achieve Results program.

    See the full article here.

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  • richardmitnick 10:00 pm on August 19, 2014 Permalink | Reply
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    From Livermore Lab: “New project is the ACME of addressing climate change” 


    Lawrence Livermore National Laboratory

    08/19/2014
    Anne M Stark, LLNL, (925) 422-9799, stark8@llnl.gov

    High performance computing (HPC) will be used to develop and apply the most complete climate and Earth system model to address the most challenging and demanding climate change issues.

    Eight national laboratories, including Lawrence Livermore, are combining forces with the National Center for Atmospheric Research, four academic institutions and one private-sector company in the new effort. Other participating national laboratories include Argonne, Brookhaven, Lawrence Berkeley, Los Alamos, Oak Ridge, Pacific Northwest and Sandia.

    The project, called Accelerated Climate Modeling for Energy, or ACME, is designed to accelerate the development and application of fully coupled, state-of-the-science Earth system models for scientific and energy applications. The plan is to exploit advanced software and new high performance computing machines as they become available.

    book

    The initial focus will be on three climate change science drivers and corresponding questions to be answered during the project’s initial phase:

    Water Cycle: How do the hydrological cycle and water resources interact with the climate system on local to global scales? How will more realistic portrayals of features important to the water cycle (resolution, clouds, aerosols, snowpack, river routing, land use) affect river flow and associated freshwater supplies at the watershed scale?
    Biogeochemistry: How do biogeochemical cycles interact with global climate change? How do carbon, nitrogen and phosphorus cycles regulate climate system feedbacks, and how sensitive are these feedbacks to model structural uncertainty?
    Cryosphere Systems: How do rapid changes in cryospheric systems, or areas of the earth where water exists as ice or snow, interact with the climate system? Could a dynamical instability in the Antarctic Ice Sheet be triggered within the next 40 years?

    Over a planned 10-year span, the project aim is to conduct simulations and modeling on the most sophisticated HPC machines as they become available, i.e., 100-plus petaflop machines and eventually exascale supercomputers. The team initially will use U.S. Department of Energy (DOE) Office of Science Leadership Computing Facilities at Oak Ridge and Argonne national laboratories.

    “The grand challenge simulations are not yet possible with current model and computing capabilities,” said David Bader, LLNL atmospheric scientist and chair of the ACME council. “But we developed a set of achievable experiments that make major advances toward answering the grand challenge questions using a modeling system, which we can construct to run on leading computing architectures over the next three years.”
    To address the water cycle, the project plan (link below) hypothesized that: 1) changes in river flow over the last 40 years have been dominated primarily by land management, water management and climate change associated with aerosol forcing; 2) during the next 40 years, greenhouse gas (GHG) emissions in a business as usual scenario may drive changes to river flow.

    “A goal of ACME is to simulate the changes in the hydrological cycle, with a specific focus on precipitation and surface water in orographically complex regions such as the western United States and the headwaters of the Amazon,” the report states.

    To address biogeochemistry, ACME researchers will examine how more complete treatments of nutrient cycles affect carbon-climate system feedbacks, with a focus on tropical systems, and investigate the influence of alternative model structures for below-ground reaction networks on global-scale biogeochemistry-climate feedbacks.

    For cryosphere, the team will examine the near-term risks of initiating the dynamic instability and onset of the collapse of the Antarctic Ice Sheet due to rapid melting by warming waters adjacent to the ice sheet grounding lines.

    The experiment would be the first fully-coupled global simulation to include dynamic ice shelf-ocean interactions for addressing the potential instability associated with grounding line dynamics in marine ice sheets around Antarctica.

    Other LLNL researchers involved in the program leadership are atmospheric scientist Peter Caldwell (co-leader of the atmospheric model and coupled model task teams) and computer scientists Dean Williams (council member and workflow task team leader) and Renata McCoy (project engineer).

    Initial funding for the effort has been provided by DOE’s Office of Science.

    More information can be found in the Accelerated Climate Modeling For Energy: Project Strategy and Initial Implementation Plan.

    See the full article here.

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  • richardmitnick 2:23 pm on August 14, 2014 Permalink | Reply
    Tags: , Climate Change   

    From Astrobiology: "Snow has thinned on Arctic sea ice" 

    Astrobiology Magazine

    Astrobiology Magazine

    Aug 14, 2014

    From research stations drifting on ice floes to high-tech aircraft radar, scientists have been tracking the depth of snow that accumulates on Arctic sea ice for almost a century. Now that people are more concerned than ever about what is happening at the poles, research led by the University of Washington and NASA confirms that snow has thinned significantly in the Arctic, particularly on sea ice in western waters near Alaska.

    A new study, accepted for publication in the Journal of Geophysical Research:Oceans, a publication of the American Geophysical Union, combines data collected by ice buoys and NASA aircraft with historic data from ice floes staffed by Soviet scientists from the late 1950s through the early 1990s to track changes over decades.

    one
    UW graduate student Melinda Webster uses a probe to measure snow depth and verify NASA airborne data. She is walking on sea ice near Barrow, Alaska, in March 2012. Credit: Chris Linder / Univ. of Washington

    Historically, Soviets on drifting sea ice used meter sticks and handwritten logs to record snow depth. Today, researchers on the ground use an automated probe similar to a ski pole to verify the accuracy of airborne measurements.

    probe
    The probe, shaped like a ski pole, includes a basket that stays on top of the snow while the tip of the probe plunges down to the sea ice below. Credit: Chris Linder / Univ. of Washington

    “When you stab it into the ground, the basket move up, and it records the distance between the magnet and the end of the probe,” said first author Melinda Webster, “You can take a lot of measurements very quickly. It’s a pretty big difference from the Soviet field stations.”

    Webster verified the accuracy of airborne data taken during a March 15, 2012 NASA flight over the sea ice near Barrow, Alaska. The following day Webster followed the same track in minus 30-degree temperatures while stabbing through the snow every two to three steps.

    The authors compared data from NASA airborne surveys, collected between 2009 and 2013, with U.S. Army Corps of Engineers buoys frozen into the sea ice, and earlier data from Soviet drifting ice stations in 1937 and from 1954 through 1991. Results showed that snowpack has thinned from 14 inches to 9 inches (35 cm to 22 cm) in the western Arctic, and from 13 inches to 6 inches (33 cm to 14.5 cm) in the Beaufort and Chukchi seas, west and north of Alaska.

    That’s a decline in the western Arctic of about a third, and snowpack in the Beaufort and Chukchi seas less than half as thick in spring in recent years compared to the average Soviet-era records for that time of year.

    “Knowing exactly the error between the airborne and the ground measurements, we’re able to say with confidence, Yes, the snow is decreasing in the Beaufort and Chukchi seas,” said co-author Ignatius Rigor, an oceanographer at the UW’s Applied Physics Laboratory.

    The authors speculate the reason for the thinner snow, especially in the Beaufort and Chukchi seas, may be that the surface freeze-up is happening later in the fall so the year’s heaviest snowfalls, in September and October, mostly fall into the open ocean.

    What thinner snow will mean for the ice is not certain. Deeper snow actually shields ice from cold air, so a thinner blanket may allow the ice to grow thicker during the winter. On the other hand, thinner snow cover may allow the ice to melt earlier in the springtime.

    Thinner snow has other effects, Webster said, for animals that use the snow to make dens, and for low-light microscopic plants that grow underneath the sea ice and form the base of the Arctic food web.

    The new results support a 15-year-old UW-led study in which Russian and American scientists first analyzed the historic Arctic Ocean snow measurements. That paper detected a slight decline in spring snow depth that the authors believed, even then, was due to a shorter ice-covered season.

    “This confirms and extends the results of that earlier work, showing that we continue to see thinning snow on the Arctic sea ice,” said Rigor, who was also a co-author on the earlier paper.

    See the full article here.

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  • richardmitnick 6:28 pm on August 12, 2014 Permalink | Reply
    Tags: , , Climate Change   

    From Astrobiology: “A global temperature conundrum: cooling or warming climate? 

    Astrobiology Magazine

    Astrobiology Magazine

    Aug 12, 2014

    When the Intergovernmental Panel on Climate Change recently requested a figure for its annual report, to show global temperature trends over the last 10,000 years, the University of Wisconsin-Madison’s Zhengyu Liu knew that was going to be a problem.

    “We have been building models and there are now robust contradictions,” says Liu, a professor in the UW-Madison Center for Climatic Research. “Data from observation says global cooling. The physical model says it has to be warming.”

    cooling
    A fisherman walks toward open water in the Antarctic ice sheet. Conflicting research on the heating and cooling of Earth has led to a global temperature conundrum, which climate scientists plan to address further this fall. Photo: iStock Photo

    Writing in the journal Proceedings of the National Academy of Sciences today, Liu and colleagues from Rutgers University, the National Center for Atmospheric Research, the Alfred Wegener Institute for Polar and Marine Research, the University of Hawaii, the University of Reading, the Chinese Academy of Sciences, and the University of Albany describe a consistent global warming trend over the course of the Holocene, our current geological epoch, counter to a study published last year that described a period of global cooling before human influence.

    The scientists call this problem the Holocene temperature conundrum. It has important implications for understanding climate change and evaluating climate models, as well as for the benchmarks used to create climate models for the future. It does not, the authors emphasize, change the evidence of human impact on global climate beginning in the 20th century.

    zy
    Zhengyu Liu

    “The question is, ‘Who is right?’” says Liu. “Or, maybe none of us is completely right. It could be partly a data problem, since some of the data in last year’s study contradicts itself. It could partly be a model problem because of some missing physical mechanisms.”

    Over the last 10,000 years, Liu says, we know atmospheric carbon dioxide rose by 20 parts per million before the 20th century, and the massive ice sheet of the Last Glacial Maximum has been retreating. These physical changes suggest that, globally, the annual mean global temperature should have continued to warm, even as regions of the world experienced cooling, such as during the Little Ice Age in Europe between the 16th and 19th centuries.

    The three models Liu and colleagues generated took two years to complete. They ran simulations of climate influences that spanned from the intensity of sunlight on Earth to global greenhouse gases, ice sheet cover and meltwater changes. Each shows global warming over the last 10,000 years.

    Yet, the bio- and geo-thermometers used last year in a study in the journal Science suggest a period of global cooling beginning about 7,000 years ago and continuing until humans began to leave a mark, the so-called “hockey stick” on the current climate model graph, which reflects a profound global warming trend.

    In that study, the authors looked at data collected by other scientists from ice core samples, phytoplankton sediments and more at 73 sites around the world. The data they gathered sometimes conflicted, particularly in the Northern Hemisphere.

    Because interpretation of these proxies is complicated, Liu and colleagues believe they may not adequately address the bigger picture. For instance, biological samples taken from a core deposited in the summer may be different from samples at the exact same site had they been taken from a winter sediment. It’s a limitation the authors of last year’s study recognize.

    “In the Northern Atlantic, there is cooling and warming data the (climate change) community hasn’t been able to figure out,” says Liu.

    With their current knowledge, Liu and colleagues don’t believe any physical forces over the last 10,000 years could have been strong enough to overwhelm the warming indicated by the increase in global greenhouse gases and the melting ice sheet, nor do the physical models in the study show that it’s possible.

    “The fundamental laws of physics say that as the temperature goes up, it has to get warmer,” Liu says.

    Caveats in the latest study include a lack of influence from volcanic activity in the models, which could lead to cooling — though the authors point out there is no evidence to suggest significant volcanic activity during the Holocene — and no dust or vegetation contributions, which could also cause cooling.

    Liu says climate scientists plan to meet this fall to discuss the conundrum.

    “Both communities have to look back critically and see what is missing,” he says. “I think it is a puzzle.”

    See the full article here.

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