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  • richardmitnick 3:55 pm on April 24, 2016 Permalink | Reply
    Tags: , Climate Change, , , New Maps Chart Greenland Glaciers' Melting Risk   

    Fron JPL: “New Maps Chart Greenland Glaciers’ Melting Risk” 

    NASA JPL Banner

    JPL-Caltech

    April 21, 2016
    Alan Buis
    Jet Propulsion Laboratory, Pasadena, California
    818-354-0474
    Alan.buis@jpl.nasa.gov

    Brian Bell
    University of California, Irvine
    949-824-8249
    bpbell@uci.edu

    Written by Carol Rasmussen
    NASA Earth Science News Team

    1
    The new maps show that the seafloor under Store Glacier, shown here, is almost 2,000 feet (600 meters) deeper than previously thought. Credits: NASA/JPL-Caltech/Ian Fenty

    Many large glaciers in Greenland are at greater risk of melting from below than previously thought, according to new maps of the seafloor around Greenland created by an international research team. Like other recent research findings, the maps highlight the critical importance of studying the seascape under Greenland’s coastal waters to better understand and predict global sea level rise.

    Researchers from the University of California, Irvine; NASA’s Jet Propulsion Laboratory, Pasadena, California; and other research institutions combined all observations their various groups had made during shipboard surveys of the seafloors in the Uummannaq and Vaigat fjords in west Greenland between 2007 and 2014 with related data from NASA’s Operation Icebridge and the NASA/U.S. Geological Survey Landsat satellites.

    NASA/Landsat 8
    NASA/Landsat 8

    They used the combined data to generate comprehensive maps of the ocean floor around 14 Greenland glaciers. Their findings show that previous estimates of ocean depth in this area were as much as several thousand feet too shallow.

    Why does this matter? Because glaciers that flow into the ocean melt not only from above, as they are warmed by sun and air, but from below, as they are warmed by water.

    2
    A comparison of the newly compiled map of the Uummannaq fjord area (left) and an older map (right). Red areas indicate shallower depths, blues and purples deeper.
    Credits: UCI/NASA/JPL-Caltech

    In most of the world, a deeper seafloor would not make much difference in the rate of melting, because typically ocean water is warmer near the surface and colder below. But Greenland is exactly the opposite. Surface water down to a depth of almost a thousand feet (300 meters) comes mostly from Arctic river runoff. This thick layer of frigid, fresher water is only 33 to 34 degrees Fahrenheit (1 degree Celsius). Below it is a saltier layer of warmer ocean water. This layer is currently more than more than 5 degrees F (3 degrees C) warmer than the surface layer, and climate models predict its temperature could increase another 3.6 degrees F (2 degrees C) by the end of this century.

    About 90 percent of Greenland’s glaciers flow into the ocean, including the newly mapped ones. In generating estimates of how fast these glaciers are likely to melt, researchers have relied on older maps of seafloor depth that show the glaciers flowing into shallow, cold seas. The new study shows that the older maps were wrong.

    “While we expected to find deeper fjords than previous maps showed, the differences are huge,” said Eric Rignot of UCI and JPL, lead author of a paper on the research. “They are measured in hundreds of meters, even one kilometer [3,300 feet] in one place.” The difference means that the glaciers actually reach deeper, warmer waters, making them more vulnerable to faster melting as the oceans warm.

    Coauthor Ian Fenty of JPL noted that earlier maps were based on sparse measurements mostly collected several miles offshore. Mapmakers assumed that the ocean floor sloped upward as it got nearer the coast. That’s a reasonable supposition, but it’s proving to be incorrect around Greenland.

    Rignot and Fenty are co-investigators in NASA’s five-year Oceans Melting Greenland (OMG) field campaign, which is creating similar charts of the seafloor for the entire Greenland coastline. Fenty said that OMG’s first mapping cruise last summer found similar results. “Almost every glacier that we visited was in waters that were far, far deeper than the maps showed.”

    The researchers also found that besides being deeper overall, the seafloor depth is highly variable. For example, the new map revealed one pair of side-by-side glaciers whose bottom depths vary by about 1,500 feet (500 meters). “These data help us better interpret why some glaciers have reacted to ocean warming while others have not,” Rignot said.

    The lack of detailed maps has hampered climate modelers like Fenty who are attempting to predict the melting of the glaciers and their contribution to global sea level rise. “The first time I looked at this area and saw how few data were available, I just threw my hands up,” Fenty said. “If you don’t know the seafloor depth, you can’t do a meaningful simulation of the ocean circulation.”

    The maps are published in a paper titled “Bathymetry data reveal glaciers vulnerable to ice-ocean interaction in Uummannaq and Vaigat glacial fjords, west Greenland,” in the journal Geophysical Research Letters. The other collaborating institutions are Durham University and the University of Cambridge, both in the U.K.; GEOMAR Helmholtz Center for Ocean Research, Kiel, Germany; and the University of Texas at Austin.

    For more information on OMG, visit:

    https://omg.jpl.nasa.gov/portal/

    NASA uses the vantage point of space to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth’s interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

    For more information about NASA’s Earth science activities, visit:

    http://www.nasa.gov/earth

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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 10:28 am on April 23, 2016 Permalink | Reply
    Tags: , Climate Change,   

    From Scientific American: “Earth Flirts with a 1.5-Degree Celsius Global Warming Threshold” 

    Scientific American

    Scientific American

    April 20, 2016
    Climate Central

    1
    Credit: Liam Moloney/Flickr, CC BY-SA 2.0

    Global leaders are meeting in New York this week to sign the Paris climate agreement. One of the expressed purposes of the document is to limit warming to “well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C.”

    A Climate Central analysis shows that the world will have to dramatically accelerate emissions reductions if it wants to meet that goal. The average global temperature change for the first three months of 2016 was 1.48°C, essentially equaling the 1.5°C warming threshold agreed to by COP 21 negotiators in Paris last December.

    February exceeded the 1.5°C target at 1.55°C, marking the first time the global average temperature has surpassed the sobering milestone in any month. March followed suit checking in at 1.5°C. January’s mark of 1.4°C, put the global average temperature change from early industrial levels for the first three months of 2016 at 1.48°C.

    1

    Climate Central scientists and statisticians made these calculations based on an average of global temperature data reported by NASA and the National Oceanic and Atmospheric Administration (NOAA). But rather than using the baselines those agencies employ, Climate Central compared 2016’s temperature anomalies to an 1881-1910 average temperature baseline, the earliest date for which global temperature data are considered reliable. NASA reports global temperature change in reference to a 1951-1980 climate baseline, and NOAA reports the anomaly in reference to a 20th century average temperature.

    NASA’s data alone showed a February temperature anomaly of 1.63°C above early industrial levels with March at 1.54°C.

    Calculating a baseline closer to the pre-industrial era provides a useful measure of global temperature for policymakers and the public to better track how successful the world’s efforts are in keeping global warming below agreed-upon thresholds.

    A similar adjustment can be applied to some of the temperature change projections in the most recent IPCC report.

    The IPCC AR5 Working Group 1 Report contains projections of future global surface temperature change according to several scenarios of future socio-economic development, most of which are presented using a baseline of 1986 to 2005. The IPCC chose this baseline in order to provide its readers a more immediate base of comparison, the climate of the present world, which people are familiar with. But these representations may suggest that the Paris goals are easier to reach than is true.

    The IPCC’s presentation of these scenarios was not designed to inform the discussion about warming limits (e.g., 1.5°C, 2°C goals of the Paris COP21 agreements). But the Panel does provide a way to make its projections of future warming consistent with discussions about targets.

    3

    IPCC estimates, using the best and longest record available, show that the difference between the 1986-2005 global average temperature value used in most of the Panel’s projections, and pre-industrial global average temperature, is 0.61°C (0.55-0.67). Neglecting 0.61°C warming is not trivial, and makes a significant difference for the assessment of the goals established in Paris. In fact, 0.61°C amounts to about half the warming already experienced thus far.

    To capture this warming and display the IPCC warming time series relative to the pre-industrial period, Climate Central adjusted a well known IPCC projection (SPM7(a)) to reflect a 1880-1910 baseline. This adjustment has a significant effect on the dates at which the 1.5 and 2°C thresholds are crossed, moving them up by about 15-20 years.

    If current emissions trends continue (RCP8.5) we could cross the 1.5°C threshold in 10 to 15 years, somewhere between the years 2025-2030, compared to 2045-2050 when a 1985-2005 baseline is used.

    The dramatic global hot streak that kicked off 2016 doesn’t mean the world has already failed to meet the goals in the Paris agreement. Three months do not make a year, and it is unlikely that 2016 will exceed the 1881-1910 climate-normal by 1.5°C. This year is also in the wake of a strong El Niño, when higher-than-average temperatures would be expected.

    And of course, exceeding the 1.5°C threshold for even an entire year would not mean that global temperatures had in fact risen to that point, never (at least within our lifetime) to drop back below it as it’s too short of a timeframe to make that determination.

    But the hot start for 2016 is a notable symbolic milestone. The day the world first crossed the 400 parts per million (ppm) threshold for atmospheric carbon dioxide heralded a future of ever increasing carbon dioxide. So too, do the first three months of 2016 send a clear signal of where our world is headed and how fast we are headed there if drastic actions to reduce carbon emissions are not taken immediately.
    Background

    On Dec.12, 2015, the 21st Conference of the Parties to the U.N. Framework Convention on Climate Change approved the Paris Agreement committing 195 nations of the world to “holding the increase in the global average temperature to well below 2°C above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5°C.” The pact commits the world to adopt nationally determined policies to limit greenhouse gas emissions in accord with those goals.

    The 2°C goal represents a temperature increase from a pre-industrial baseline that scientists believe will maintain the relatively stable climate conditions that humans and other species have adapted to over the previous 12,000 years. It will also minimize some of the worst impacts of climate change: drought, heat waves, heavy rain and flooding, and sea level rise. Limiting the global surface temperature increase to 1.5°C would lessen these impacts even further.

    1.5 and 2°C are not hard and fast limits beyond which disaster is imminent, but they are now the milestones by which the world measures all progress toward slowing global warming. And yet it is surprisingly difficult to find objective measures that answer the question, where are we today on the path toward meeting the 1.5 or 2°C goals?

    Every month NOAA and NASA update their global surface temperature change analysis, using data from the Global Historical Climate Network, and methods validated in the peer-reviewed literature (Hansen et al. 2010; NCDC). The monthly updates are posted on their websites, and made available to the public along with the underlying data and assumptions that go into their calculations.

    These calculations are enormously useful for understanding the magnitude and pace of global warming. In fact, they are the bedrock measurements validating the fact that our planet is warming at all.

    But none present their results in comparison to a pre-industrial climate normal.
    Methods and Results

    The NASA and NOAA monthly updates are presented as anomalies, or as the deviation from a baseline climate normal, calculated as an average of a 30-year reference period, or the 20th century average; they do not represent an absolute temperature increase from a specific date. NASA presents their results in reference to a 1951 to 1980 average temperature, NOAA in reference to a 20th century average temperature.

    The NASA results, calculated by Goddard Institute for Space Studies are published monthly on the NASA/GISS website (GISTEMP). NOAA methods and monthly updates are published via the National Centers for Environmental Information here.

    Climate Central used data from NASA and NOAA to create an 1881 to 1910 climate normal for the months of January, February, and March. We then compared the reported monthly 2016 anomaly for each of these months to this “early-industrial” baseline reference period. These anomalies were then averaged to produce a mean monthly NASA/NOAA anomaly for each month. The results are presented below.

    The NASA anomaly is considerably higher than the anomaly reported by NOAA. This reflects the fact the NASA’s calculations are tuned to account for temperature changes at the poles, where there are far fewer monitoring stations. NOAA relies only on historical station data and makes no adjustment to account for sparse records at the poles, where warming has been more rapid relative to non-polar regions.

    4

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  • richardmitnick 8:40 am on April 21, 2016 Permalink | Reply
    Tags: , , Climate Change,   

    From AAAS: “Climate catastrophe? A half a degree warming could make the difference” 

    AAAS

    AAAS

    Apr. 21, 2016
    Christina Reed

    1
    The reduction in annual water availability will be far more pronounced in a 2°C world compared with 1.5°C global warming. This file photo from 2007, shows a drought-stricken reservoir in the Alassa village near Limassol, Cyprus. P. Karadjias/AP

    Last December in Paris, 195 nations agreed to slow the planet’s warming trend by cutting their greenhouse gas emissions. Their goal was to prevent more than 2°C of additional warming. But even before the meeting, scientists questioned whether that target was too high. A study presented here today at the European Geophysical Union’s (EGU) annual meeting backs up those concerns, providing new evidence that such warming could still lead to catastrophic droughts and sea level rise. But reducing the threshold by just half a degree, to 1.5°C, the scientists say, would make a world of difference.

    To conduct the study, Carl Schleussner, a scientific adviser at Climate Analytics in Berlin, and an international team of researchers analyzed 11 different indicators of climate impacts, including extreme weather events, water availability, crop yields, coral reef degradation, and sea-level rise for 26 non-polar areas around the world. To do this, they compiled simulations from a wealth of existing climate models, including those used by the Intergovernmental Panel on Climate Change and an ensemble of general ocean and atmosphere circulation models.

    The results of these simulations confirmed that areas already known to be vulnerable to climate change will be at even greater risk if the planet warms by 2 ̊C than by 1.5 ̊C, the team reports in the study, also published today in Earth System Dynamics. For example, warm spells in the tropics would last up to 50% longer—so that virtually all coral reefs in warmer tropical waters would be at risk of severe degradation after 2050. Under a 1.5 ̊C warming scenario, the threat to those reefs wouldn’t be significantly different before 2050—in both situations an expected degradation of the tropical coral ecosystems is likely to begin by 2030 regardless. But more of them—about 30%—would survive until 2100.

    “Some researchers have argued that there is little difference in climate change impacts between 1.5°C and 2°C,” said study co-author Jacob Schewe, a climate physicist at the Potsdam Institute for Climate Impact Research in Germany. He acknowledges that certain factors such as natural variability and model uncertainties need to be accounted for because they can obscure the picture. “We did that in our study, and by focusing on key indicators at the regional level, we clearly show that there are significant differences in impacts between 1.5°C and 2°C,” he added in a statement to the press.

    Certain places are particularly vulnerable, Schewe says. “There are tipping points in the system such as the Greenland ice sheet where if it were to melt, the mechanisms there are irreversible.” Scientists can’t say with certainty where that tipping point is exactly, he adds—but they estimate that it’s somewhere between 1.5 ̊C and 2.5 ̊C. “So going for 1.5 ̊C is much safer.”

    The paper cites a number of ways to assess the significance of an extra half-degree of warming. Crop yields of maize and wheat in Central America and West Africa, for example, would dwindle by twice as much under 2°C, when compared with 1.5°C, the team found. And sea levels would rise an extra 10 centimeters by 2100 (due both to the physical expansion of ocean waters as they warm, as well as to water added from melting ice sheets). “Sea level rise will slow down during the 21st century only under a 1.5°C scenario,” Schleussner explained.

    Slowing sea-level rise also has a significant impact on regions frequently inundated by storm surges due to tropical storms, such as the Philippines. “Typhoon Haiyan in 2013 set a new benchmark for storm surges,” says geologist Janneli Lea Soria of the Earth Observatory of Singapore, who was not involved in the new study. A poster she presented at EGU this week showed that the typhoon pushed beach and ocean sediments inland by nearly 2 kilometers in some locations.

    In the Mediterranean, 2 ̊C warming would cut water availability by 20% by the late 21st century, compared with a 10% reduction from 1.5 ̊C warming, the team found. A separate study, also presented today at EGU by paleoclimatologist Joel Guiot of CNRS, CEREGE, in Aix-en-Provence, France, puts that into historical context. Looking back over the last 10,000 years of pollen data for the Mediterranean, Guiot found that severe drought has changed vegetated areas in the region by 10% to 15%—often pushing margins of the land cover in other directions.

    Projecting forward, Guiot found little difference in changes to vegetation cover between 1.5 ̊C and 2 ̊C until 2050. After that, however, a 1.5 ̊C threshold keeps land changes in the realm of droughts seen in the past, Guiot says. NASA identifies the current drought in the Mediterranean as the worst in 900 years. “But if we go to 2 ̊C, we see we are at the maximum range of change seen during the Holocene [dating back about 10,000 years]. And if we go to 3 ̊C we will reach a situation that never existed [in the Holocene] before.”

    On 22 April—Earth Day—the climate agreement signed in Paris will be available for the signatures of heads of state around the world at the United Nations’ headquarters in New York City for one year. At least 55 countries representing 55% of the world’s emissions need to ratify the final agreement that came out of the December climate conference in order to see it put into force. That agreement reflects the urging from Pacific island nations and others calling themselves “most vulnerable” to climate change to aim for a more stringent target of 1.5°C, “recognizing that this would significantly reduce the risks and impacts of climate change.”

    For most of the indicators, “It’s not the timing, but the level of warming,” Schewe says. “And as soon as we reach that warming we see the impacts associated with it.”

    See the full article here .

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  • richardmitnick 10:50 am on April 16, 2016 Permalink | Reply
    Tags: Ancient volcanoes could be key to predicting impact of climate change, , Climate Change, ,   

    From USC: “Ancient volcanoes could be key to predicting impact of climate change” 

    USC bloc

    University of Southern California

    April 13, 2016
    Andrew Good

    1
    Researchers think emissions from volcanos, such as the one seen here, may have led to a dramatic rise in CO2 leading to a mass extinction 200 million years ago. (Photo/NASA Earth Observatory)

    Just over 200 million years ago, long before the demise of the dinosaurs, a cataclysm killed off a significant chunk of the planet’s animal life. The leading theory implicates massive volcanic eruptions, triggered when the supercontinent of Pangea was ripped apart into separate continents.

    A new study co-authored by USC researchers strengthens evidence for that theory and has wider implications for how rapid climate change can affect life on Earth. Along with lava flows, the volcanic eruptions released massive amounts of the greenhouse gas carbon dioxide, creating havoc in the ecosystem.

    The study*, published April 6 in Nature Communications, charts the sharp escalation of the element mercury in samples of rock preserved from the Triassic-Jurassic extinction event. It isn’t the ordinary mercury you’d find on the surface of the planet: Isotopic data suggests it can be traced to the eruptions.

    Frank Corsetti, a geobiologist at the USC Dornsife College of Letters, Arts & Sciences, was a co-author on the study along with USC professors David Bottjer, Josh West and William Berelson; current USC graduate student Joyce Yager; and a host of current and past graduate students, including Kathleen Ritterbush, now an assistant professor at the University of Utah, and Yadira Ibarra, now a postdoctoral research fellow at Stanford University.

    Mercury rising

    Corsetti said the rise in mercury seems to match changes in the planet’s biosphere during the era. As the mercury was found to rise in the rock samples, it matched a wave of animal extinctions on the planet’s surface and in its seas. The mass extinction peaks just as the level of mercury does; biodiversity begins to return once the mercury level recedes, about 700,000 years after the event began.

    The mercury, Corsetti said, serves as a kind of fingerprint for a massive volcanic eruption in what’s known as the Central Atlantic Magmatic Province (CAMP). Essentially, CAMP was the spot in Pangea where the Atlantic Ocean would later appear after the land mass split.

    CAMP’s appearance was a cataclysm on its own.

    “If that much material erupted today, it would cover the contiguous United States with about 400 meters of lava — it was an enormous series of eruptions,” Corsetti said.

    But the reason CAMP is suspected of being the culprit in the mass extinction has to do with carbon dioxide — the gas that climate change experts now worry is being released into the atmosphere in rapid and massive quantities.

    “By some estimates, it rose nearly as rapidly as we’re putting CO2 into the atmosphere today,” Corsetti said. “We wanted to see how the Earth system responded from a rapid rise of CO2. The spoiler alert is there was a mass extinction. What we’ve been able to do is use this mercury as a fingerprint to tie the event to the volcanos, and therefore the emissions.”

    The Triassic-Jurassic extinction is particularly pertinent because it was selective, Corsetti said. It preferentially affected coral reefs and animals most similar to the ones common in today’s oceans. An earlier and more severe event, the Permian extinction — sometimes called “the mother of all extinctions” — was even bigger, but the dominant organisms affected were different from the ones common today.

    That makes the T-J event perhaps the most relevant mass extinction to study when trying to predict what might happen with rising CO2 levels, Corsetti said.

    The study was sponsored by the National Science Foundation, the Roger E. Deane Postdoctoral Fellowship, the Geological Society of America, the Society for Sedimentary Geology, the American Philosophical Society, the Natural Sciences and Engineering Research Council of Canada and the Canadian Institute for Advanced Research.

    *Science paper:
    Mercury anomalies and the timing of biotic recovery following the end-Triassic mass extinction

    Science team and affiliations:

    Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada
    Alyson M. Thibodeau & Bridget A. Bergquist
    Department of Earth Sciences, Dickinson College, Carlisle, Pennsylvania 17013, USA
    Alyson M. Thibodeau
    Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84103, USA
    Kathleen Ritterbush
    Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA
    Joyce A. Yager, A. Joshua West, David J. Bottjer, William M. Berelson & Frank A. Corsetti
    Department of Earth System Science, Stanford University, Stanford, California 94305, USA
    Yadira Ibarra

    Contributions

    D.J.B., F.A.C. and A.J.W. conceived the study and designed it with A.M.T. and B.A.B. K.R., J.A.Y. and Y.I. collected the samples. A.M.T. and J.A.Y. collected, analysed and interpreted the mercury and carbon data, respectively, with B.A.B., A.J.W., W.M.B. and F.A.C. K.R. provided the stratigraphic and paleoenvironmental context as well as the paleoecological data. K.R., Y.I. and F.A.C. were responsible for paleoenvironmental interpretation. F.A.C., J.A.Y., A.J.W. and A.M.T. conceived and drafted the figures. F.A.C. and A.M.T. wrote the paper with contributions from all other co-authors.

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    The University of Southern California is one of the world’s leading private research universities. An anchor institution in Los Angeles, a global center for arts, technology and international business, USC’s diverse curricular offerings provide extensive opportunities for interdisciplinary study, and collaboration with leading researchers in highly advanced learning environments. With a strong tradition of integrating liberal and professional education, USC fosters a vibrant culture of public service and encourages students to cross academic as well as geographic boundaries in their pursuit of knowledge.

     
  • richardmitnick 1:28 pm on February 8, 2016 Permalink | Reply
    Tags: , , Climate Change, , Sea level rise and global warming   

    From LLNL: “Consequences of today’s carbon emissions will linger for thousands of years, study finds” 


    Lawrence Livermore National Laboratory

    Feb. 8, 2016
    Anne M Stark
    stark8@llnl.gov
    925-422-9799

    Carbon emissions
    Carbon emissions in carbon dioxide

    The Earth may suffer irreversible damage that could last tens of thousands of years because of the rate humans are emitting carbon into the atmosphere.

    In a new study in Nature Climate Change, researchers at Oregon State University, Lawrence Livermore National Laboratory and collaborating institutions found that the longer-term impacts of climate change go well past the 21st century.

    “Much of the carbon we are putting in the air from burning fossil fuels will stay there for thousands of years — and some of it will be there for more than 100,000 years,” said Peter Clark, an Oregon State University paleoclimatologist and lead author on the article. “People need to understand that the effects of climate change on the planet won’t go away, at least not for thousands of generations.”

    LLNL’s Benjamin Santer said the focus on climate change at the end of the 21st century needs to be shifted toward a much longer-term perspective.

    “Our greenhouse gas emissions today produce climate-change commitments for many centuries to come,” Santer said. “Today’s actions — or inaction — will have long-term climate consequences for generations of our descendants.”

    “The long-term view sends the chilling message what the real risks and consequences are of the fossil fuel era,” said Thomas Stocker of the University of Bern in Switzerland, who is past co-chair of the Intergovernmental Panel on Climate Change’s (IPCC) Working Group I. “It will commit us to massive adaptation efforts so that for many, dislocation and migration becomes the only option.”

    Sea level rise is one of the most noticeable impacts of global warming, yet its effects are just starting to be seen, according to the article. The latest IPCC report calls for sea level rise of one meter by the year 2100. In the new study, however, the authors look at four different sea level-rise scenarios based on different rates of warming, from a low rate that could only be reached with massive efforts to eliminate fossil fuel use over the next few decades, to a higher rate based on the consumption of half the remaining fossil fuels over the next few centuries.

    With just two degrees (Celsius) warming in the low-end scenario, sea levels are predicted to eventually rise by about 25 meters. With seven degrees warming at the high-end scenario, the rise is estimated at 50 meters, although over a period of several centuries to millennia.

    “It takes sea level rise a very long time to react — on the order of centuries,” Clark said. “It’s like heating a pot of water on the stove; it doesn’t boil for quite a while after the heat is turned on — but then it will continue to boil as long as the heat persists. Once carbon is in the atmosphere, it will stay there for tens or hundreds of thousands of years, and the warming, as well as the higher seas, will remain.”

    For the low-end scenario, an estimated 122 countries have at least 10 percent of their population in areas that will be directly affected by rising sea levels, and some 1.3 billion people — or 20 percent of the global population — may be directly affected. The impacts become greater as the warming and sea level rise increases.

    The new paper makes the fundamental point that considering the long time scales of the carbon cycle and of climate change means that reducing emissions slightly or even significantly is not sufficient. “To spare future generations from the worst impacts of climate change, the target must be zero — or even negative carbon emissions — as soon as possible,” Clark said.

    The researchers’ work was supported by the U.S. National Science Foundation, the U.S. Department of Energy, the Natural Sciences and Engineering Research Council of Canada, the German Science Foundation and the Swiss National Science Foundation.

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  • richardmitnick 12:10 pm on January 26, 2016 Permalink | Reply
    Tags: , Climate Change, , East African Rift zone,   

    From Eos: “Scientists Discover a New Source of Atmospheric Carbon Dioxide” 

    Eos news bloc

    Eos

    1.26.16
    JoAnna Wendel

    Rift zone faults cut across the East African rift
    Faults cut across the East African Rift zone, where the slow motion of the Nubian and Somalian plates of Earth’s crust pulls the continent apart. Scientists have found that faults in this zone contribute significant amounts of carbon dioxide to the atmosphere every year. To give a sense of scale, the vegetated (green) valley floor at the lower right is 17 kilometers long. Credit: ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center

    Researchers have discovered a previously unknown source of carbon dioxide leaking into the atmosphere. The gas emerges from faults where the slow separation of plates of the planet’s continental crust is cracking and deforming the Earth.

    Techtonic plates
    The tectonic plates of the world were mapped in the second half of the 20th century.

    Faults in the East African Rift zone release about 71 megatons of carbon dioxide (CO2) into the atmosphere every year—a value comparable to CO2 leaking from volcanic chains that stitch across the sea beds of many of Earth’s oceans and mark where new oceanic crust is forming—according to a new study published last week in Nature Geoscience.

    Although researchers have long investigated the East African Rift, none of them have explored if “the Rift could release CO2 along the faults,” said Hyunwoo Lee, lead author on the paper and a doctoral student at the University of New Mexico.

    The discovery of a new significant source of CO2 gives scientists a more complete picture of natural sources of atmosphere-warming CO2, said James Muirhead, a doctoral student at the University of Idaho, Moscow, and a coauthor on the study. In addition to the East African Rift zone, a handful of other continental rift zones dot the planet, such as the Basin and Range in the southwestern United States and the Eger Rift in central Europe.

    “This relevant result highlights how diffuse degassing along continental rifts is a main source of carbon dioxide to the atmosphere, not considered until now, which in the past, such as in the Cretaceous during widespread continental rifting, could have dramatically modified the climate of the Earth,” said Giovanni Chiodini, a researcher at the National Institute of Geophysics and Volcanology in Naples, Italy, who was not involved in the research. “Despite [CO2’s] major role in modulating Earth’s climate, we remain largely unaware of the processes governing the natural fluxes of carbon between Earth reservoirs and the atmosphere.”

    However, the new source doesn’t play as major a role in influencing climate as human-driven emissions of greenhouse gases, Muirhead noted. “Even though this is a large amount, it’s still on the order of 500 times smaller than human outputs” of CO2, which exceeded 36 gigatons in 2013.

    Deep Magma Bodies

    Previous research found CO2 seeping from faults in Italy, which inspired Lee and his colleagues to look at the East African Rift zone (EAR). Because the EAR is so large—stretching thousands of kilometers across northeastern Africa—it offers many more faults to study.

    A lot of magma can build up beneath such an extensive rift zone, “so you have the potential to produce a lot more CO2 coming into the atmosphere,” said Muirhead.

    The researchers collected CO2 samples from fault zones around the Natron-Magadi region of the rift valley, at the border between Kenya and Tanzania, to assess “diffuse degassing”—seepage of small amounts of CO2 over a large area. They then analyzed the samples to determine their origins. Carbon dioxide from magma sources generally contains a higher ratio of the heavier carbon isotope, carbon-13 (13C), compared to the lighter isotope, carbon-12 (12C). Conversely, more 12C compared to 13C indicates biogenic origins. In this case, the researchers found more of the heavier isotope, which means the CO2 was originating from magma deep below the Earth’s surface.

    Simultaneously, the researchers tracked seismic activity in the region, Lee said. Using an already established network of seismic instruments, the researchers observed constant earthquakes occurring deep below the crust—sometimes as deep as 30 kilometers, Muirhead said, indicating that CO2 seepage from the rift valley comes from deeper within the Earth than the CO2 spewed by active volcanoes, which are powered by magma closer to the surface. The researchers suspect that the magma bodies supplying the CO2 lie in the lower portion of the Earth’s crust or even in the upper mantle.

    The researchers found that the Natron-Magadi region of the EAR releases about 4 megatons of CO2 every year. If that’s typical of the entire rift valley, then the system is releasing 71 megatons per year, the team calculated.

    Mid-ocean ridges across the globe pump out about 53–97 megatons of carbon dioxide per year, but most of it dissolves into the ocean or recycles back into the Earth’s crust through subduction, Muirhead said. On land, CO2 degassing from continental rifting has no such buffer and enters the atmosphere directly.

    According to Lee and his colleagues, that the EAR rivals the output of all mid-ocean ridges means that continental rifting could be a significant player in long-term shifts of Earth’s climate and that active volcanoes aren’t the only places where CO2 emerges naturally.

    Citation: Wendel, J. (2016), Scientists discover a new source of atmospheric carbon dioxide, Eos, 97, doi:10.1029/2016EO044671. Published on 26 January 2016.

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    Eos is the leading source for trustworthy news and perspectives about the Earth and space sciences and their impact. Its namesake is Eos, the Greek goddess of the dawn, who represents the light shed on understanding our planet and its environment in space by the Earth and space sciences.

     
  • richardmitnick 10:18 am on January 19, 2016 Permalink | Reply
    Tags: , Climate Change, Deep Ocean Waters Trapping Vast Stores of Heat, ,   

    From SA: “Deep Ocean Waters Trapping Vast Stores of Heat” 

    Scientific American

    Scientific American

    January 19, 2016
    John Upton

    Temp 1
    ©iStock.com

    A new generation of scientific instruments has begun scouring ocean depths for temperature data, and the evidence being pinged back via satellite warns that the consequences of fossil fuel burning and deforestation are accumulating far below the planet’s surface.

    More than 90 percent of the heat trapped by greenhouse gas pollution since the 1970s has wound up in the oceans, and research published Monday revealed that a little more than a third of that seafaring heat has worked its way down to depths greater than 2,300 feet (700 meters).

    Plunged to ocean depths by winds and currents, that trapped heat has eluded surface temperature measurements, fueling claims of a “hiatus” or “pause” in global warming from 1998 to 2013. But by expanding cool water, the deep-sea heat’s impacts have been indirectly visible in coastal regions by pushing up sea levels, contributing to worsening high-tide flooding.

    “The heat’s going in at the surface, so it’s getting down pretty deep,” said Glen Gawarkiewicz, a Woods Hole Oceanographic Institution scientist who was not involved with the study. “With 35 percent of the heat uptake going below 700 meters, it really points out the importance of continued deep ocean sampling. It was a surprise to me that it was that large of a fraction.”

    The research, published in Nature Climate Change, was led by Lawrence Livermore National Laboratory. It compared modeling results with data from a mishmash of sources, most notably from a nascent fleet of monitoring devices called deep Argo floats.

    The researchers concluded that half of overall ocean warming has occurred since 1997—a date that they noted in their paper was “nearly coincident with the beginning of the observed surface warming hiatus.”

    Temp 2
    Credit: Lawrence Livermore/Nature Climate Change

    A combination of climate pollution, a recent change in a long-running cycle of the Pacific Ocean and the current El Niño has led to a spike in warming rates recorded at the surface of the planet. That followed a surface warming slowdown; 2014 and 2015 were the warmest years on record globally.

    Research groups from around the world have deployed thousands of Argo floats to measure since around the year 2000 to take temperature, salinity and other measurements. Technological advances have allowed a small fleet of deeper-diving floats to be deployed more recently. Some of those have been built to dive as deep as 20,000 feet.

    “Knowing how much the ocean is warming and how fast and where are all important for knowing how much the atmosphere is going to warm and how much seas are going to rise,” said Gregory C. Johnson, a National Oceanic and Atmospheric Administration scientist who works on that agency’s Argo float program.

    Monday’s paper used the new deep-sea Argo data to expand on a paper published in 2014 by Lawrence Livermore and other researchers, which revealed high levels of warming in the ocean’s surface layer.

    “The oceans as an energy store are really doing a lot of the work,” said Lawrence Livermore researcher Paul Durack, who helped produce the studies that were published Monday and in 2014. “The actual temperature change is relatively small, but due to the huge heat capacity of the oceans this equates to a very, very large heat content change.”

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  • richardmitnick 9:22 am on January 18, 2016 Permalink | Reply
    Tags: , Climate Change, ,   

    From livescience: ” 727 People on Chesapeake Bay Island Could Become America’s First ‘Climate Refugees’ “ 

    Livescience

    December 11, 2015
    Stephanie Pappas

    Temp 1
    An aerial view of the town of Tangier on Tangier Island in Virginia’s Chesapeake Bay. Homes sit on yards bordered by estuarine marshes and tidal creeks. Most of the 700 or so inhabitants of Tangier get around on foot or by bicycle or golf cart. Credit: U.S. Army Corps of Engineers & David Schulte

    Rising seas will likely render the last inhabited island in Virginia uninhabitable in 50 years, a new study finds.

    The Chesapeake Bay’s Tangier Island, the site of the town of Tangier (population 727), will become uninhabitable under a midrange estimate of sea level rise due to climate change by 2063, researchers report in the Dec. 10 issue of the journal Scientific Reports.

    Already, more than 500 lower-level islands in the Chesapeake Bay have vanished since Europeans first arrived in the area in the 1600s, said study leader David Schulte, an oceanographer with the U.S. Army Corps of Engineers Norfolk District. Engineering efforts could shore up Tangier, Schulte told Live Science, but saving the island and its neighbors will ultimately require action on climate.

    “There are actions that we can take,” he said. “But obviously the best action we could take would be to do something about the bigger issue.”

    Tangier is one of the Tangier Islands, a series of grassy spits of land about 14 miles (22 kilometers) east of mainland Virginia, within the Chesapeake Bay. Tangier is the southernmost of the islands, which also include Goose Island, Uppards Island and Port Isobel.

    Temp 2
    A seawall protects the small airport at the town of Tangier on Tangier Island. Erected in 1989, this seawall keeps erosion from storms and sea level rise at bay on the western end of the island. New research, however, suggests that the island will be uninhabitable by 2063.
    Credit: U.S. Army Corps of Engineers & David Schulte

    Thirty-nine islands in the Chesapeake Bay were once habitable, Schulte said. Today, Tangier and Smith Island in Maryland are the only two that remain so. Erosion and sea level rise (and, to some extent, other factors like land subsidence due to groundwater pumping) have eaten away at the rest.

    Reliable maps of the Tangier Islands date back to the 1850s. Schulte and his colleagues compared these maps to the modern geography of the islands and then using projected rates of local sea level rise to estimate land loss in the future. Sea level has been rising globally between 0.04 and 0.1 inches (0.1 and 0.25 centimeters) per year, according to the National Oceanic and Atmospheric Administration, and that rate is accelerating. In addition, because of local geology, wind and ocean patterns, some regions will see relatively larger sea level increases. One such hotspot is along the U.S. East Coast from Boston, Massachusetts to Cape Hatteras, North Carolina, a stretch that includes the Chesapeake Bay.

    Already, 66.75 percent of the Tangier Islands’ 1850 land mass has been lost, Schulte and his colleagues found. On the west side of Tangier Island, erosion from large storms plays a big role in the loss, Schulte said. On the east side, gradual sea level rise is mostly to blame.

    A conservative, midrange estimate of sea level rise gives Tangier Island a mere 50 years to live, Schulte said. “If you take the more extreme high sea level rise, they’ve got about half the time, maybe 25 years,” he said.

    To the north, Goose Island is likely to be inundated by 2038 in the midrange sea level rise scenario, and Uppards will be mostly inundated by 2063 and gone by 2113. As firm land converts to sea marsh, the town of Tangiers will likely be uninhabitable by 2063.

    Climate displacement?

    That could make the 700 or so townspeople of Tangier the first climate refugees in the United States, Schulte said. And the loss of the islands has ecological and economic consequences, too. By 2063, an estimated $1.75 million per of “ecological services,” such as water filtration, bird nesting habitat and blue crab habitat, will be lost, Schulte said.

    A rock wall on Tangier Island, built in 1989, already protects a small airport from erosion. Other engineering solutions, like breakwaters and man-made dunes, could extend the life of the island by a few decades, Schulte said. The changes in the island, however, are already visible to the naked eye. A settlement on the island’s north end called Canaan was abandoned in the 1920s because of frequent flooding, but 10 years ago, visitors could still see old foundations and a graveyard, Schulte said. Today, it’s all gone.

    “What was land is now underwater,” Schulte said.

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  • richardmitnick 1:05 pm on December 15, 2015 Permalink | Reply
    Tags: , Climate Change,   

    From phys.org: “New research improves global climate models” 

    physdotorg
    phys.org

    December 15, 2015
    Leah Burrows

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    Clouds move over the Amazon rainforest. No image credit.

    When it comes to understanding climate change, there is the easy part and the hard part. The easy part is understanding how greenhouses gasses such as carbon dioxide and methane trap solar radiation and warm the planet. The hard part is figuring out how atmospheric particles impact cloud formation, which scatters solar radiation and cools the planet.

    Clouds, as you probably learned in grade school, are created as evaporated water forms droplets around airborne particles. Prior to the industrial revolution, these particles came from organic sources, like plants, or naturally occurring wildfires, dust storms, and sea spray. But beginning around 1750, humans have poured carbon, sulfate and other aerosols into the atmosphere, increasing atmospheric particulates up to 100-fold in many locations.

    How this increase is affecting global climate change is unclear, in part because little is known about the behavior of these particles.

    Now, research led by the John A. Paulson School of Engineering and Applied Sciences (SEAS) provides a new twist to a recently proposed theory about atmospheric particulates and paints a clearer picture of how these particles behave. The research, published in Nature Geoscience, found that atmospheric particles tied to plant life can be either solid or liquid depending on the environment in which they form. The findings expand on a previous study that posited such particles favor a solid state.

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    “These findings swing the scientific pendulum,” said Scot Martin, the Gordon McKay Professor of Environmental Chemistry, who led the research. “Clouds behave differently depending on whether they form on populations of solid or liquid particles. The state of the particles will determine which processes to include in models predicting climate change, enhancing the accuracy of these models.”

    The research was conducted in collaboration with Amazonas State University, University of São Paulo, and the National Institute of Amazonian Research as part of the GoAmazon2014/5 project supported by the Department of Energy.

    The previous research, which found that atmospheric particles over forests are in a solid or semisolid state, was conducted in a boreal (pine) forest in Finland. There, pine trees release alpha-pinene, an organic building block that reacts with other substances such as ozone to produce atmospheric organic particulate matter. (Alpha-pinene is also what we smell when we smell pine.)

    Martin and his team decided to test that theory in the Amazon rainforest, which has about 80 percent humidity, compared to the pine forest’s 30 percent. In the Amazon, the reaction products of the compound isoprene provides the basic building block for atmospheric organic particulate matter.

    The team found that 80 percent of the time, the atmospheric organic particles that formed in the Amazon were in a liquid state. Liquid particles absorb molecules from the gas phase and grow. Semi-solid particles, on the other hand, grow layer by layer and remain smaller, which affects the types of clouds that form and their propensity to rain.

    “Our study found that regionality plays an important role in the state of liquid and dry particles,” said Adam Bateman, a postdoctoral fellow at SEAS and first author of the study. “The state of the particles depends on where you are, the kind of biome you have, and what the trees are emitting. Pine trees emit different compounds and do so in drier conditions, with the net result of particles that are semi-solid, and climate modeling will be different as a result.”

    The research in the Amazon also provides a window back in time, to a pre-industrial world. Because the Amazon is so remote, it is protected from an influx of particles caused by industrial pollution.

    “The Amazon represents a natural laboratory to explore what the world was like in 1750,” Martin said. “Here, we can ask questions about how these particles occur naturally, how big they get and what kind of clouds they form—and then compare that to the modern world. This research touches on all the topics of climate change that we need to think about, whether particulates are organic or not.”

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 11:26 am on December 15, 2015 Permalink | Reply
    Tags: , Climate Change, , Water in the Andes   

    From Ohio State: “Innovation in the Andes” 

    OSU

    Ohio State University

    December 14, 2015
    No writer credit

    Ohio State is known around the world for its climate change research. Now, scientists are using new ideas to study melting glaciers in the Peruvian Andes.


    download mp4 video here.

    In Huaraz, Peru, it’s easy to see the potentially devastating effects of climate change.

    About 150,000 people in the town live and work alongside glaciers; the melting ice provides much of Huaraz’s water during the dry season. But as the melting continues, flooding and water shortages will be disastrous to a region economically dependent on farming.

    The Peruvian glaciers and wetlands tell the story of climate change, which is threatening the water supply for millions of people in Latin America and crops eaten around the world. But gathering data is difficult: Thin air and high altitudes pose problems for researchers.

    ”It’s really hard to get into these locations and requires a lot of hiking and investment of time,Off the cuff, I was thinking it would be cool to send something up to do the work while we could hang out in the valley.”–Oliver Wigmore, a doctoral student in geography at Ohio State.

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    Wigmore needed an innovative solution. So he designed aerial drones specifically to collect data at elevations above 4,000 meters.

    The drones — more formally known as unmanned aerial vehicles (UAVs) — have become critical tools in the Byrd Polar and Climate Research Center’s quest to create 3-D maps of glacier changes and water resources in the Cordillera Blanca mountain range.

    Before Wigmore’s idea, UAVs were not widely used. Off-the-shelf models were expensive, and researchers in the field would lose precious time waiting for repairs when UAVs crashed.

    Wigmore builds his own drones, tricking them out with high-speed motors and oversized propellers. He buys components on the cheap and builds them based on instructions he finds on the Internet.

    Using the data, Wigmore and his colleagues create highly detailed maps of glaciers and wetlands in Peru.

    The maps bridge the gap between high-level satellite views of the region and point measurements providing valuable knowledge for water resource planning for communities.

    “UAVs offer some of the only technology available today for gathering data on a scale to inform local water management decisions,” he said.

    Wigmore’s research has discovered dramatic changes in glaciers near Huaraz, including a 50-foot ice loss and collapse of the ice cliff. The maps also have uncovered a local groundwater system that is capturing and storing some of the meltwater in springs, where people will be able to access it even after the glaciers are gone.

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    “There will still be a significant drop in water supply eventually, but there may be some potential for the groundwater to buffer it,” Wigmore says.

    The research is good news for billions of people living in China and India, who rely on Himalayan glaciers for water. Following Wigmore’s example, scientists there can use UAVs to plan water for conservation in the face of climate change. Food, drinking water and energy resources depend on it.

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