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  • richardmitnick 11:33 am on July 24, 2017 Permalink | Reply
    Tags: , Climate Change, , ,   

    From CSIRO: “Extreme El Niño events to stay despite stabilisation” 

    CSIRO bloc

    Commonwealth Scientific and Industrial Research Organisation

    25 Jul 2017
    Chris Gerbing
    Communication Manager, Oceans And Atmosphere
    Phone +61 3 9545 2312
    Chris.Gerbing@csiro.au

    The frequency of extreme El Niño events is projected to increase for a further century after global mean temperature is stabilised at 1.5°C above pre-industrial levels.

    1
    Yale.

    Research published today in Nature Climate Change by an international team shows that if warming was halted to the aspirational 1.5°C target from the Paris Agreement, the frequency of extreme El Niño events could continue to increase, due to a continuation of faster warming in the eastern equatorial Pacific.

    CSIRO researcher and lead author Dr Guojian Wang said the growing risk of extreme El Niño events did not stabilise in a stabilised climate.

    “Currently the risk of extreme El Niño events is around five events per 100 years,” Dr Wang said.

    “This doubles to approximately 10 events per 100 years by 2050, when our modelled emissions scenario (RCP 2.6) reaches a peak of 1.5°C warming.

    “After this, as faster warming in the eastern equatorial Pacific persists, the risk of extreme El Niño continues upwards to about 14 events per 100 years by 2150.

    “This result is unexpected and shows that future generations will experience greater climate risks associated with extreme El Niño events than seen at 1.5°C warming.”

    The research was based on five climate models that provided future scenarios past the year 2100.

    The models were run using the Intergovernmental Panel on Climate Change’s lowest emissions scenario (RCP2.6), which requires negative emissions late in the century.

    Director of the Centre for Southern Hemisphere Oceans Research and report co-author, Dr Wenju Cai, said that this research continues important work on the impacts of climate change on the El Niño-Southern Oscillation which is a significant driver of global climate.

    “The most severe previous extreme El Niño events occurred in 1982/83, 1997/98 and 2015/16, years associated with worldwide climate extremes,” Dr Cai said.

    “Extreme El Niño events occur when the usual El Niño Pacific rainfall centre is pushed eastward toward South America, sometimes up to 16,000 kilometres, causing massive changes in the climate. The further east the centre moves, the more extreme the El Niño.

    “This pulls rainfall away from Australia bringing conditions that have commonly resulted in intense droughts across the nation. During such events, other countries like India, Ecuador, and China have experienced extreme events with serious socio-economic consequences.”

    Dr Cai added that while previous research suggested that extreme La Niña events would double under a 4.5°C warming scenario, results here indicated that under a scenario of climate stabilisation (i.e. 1.5°C warming) there was little or no change to these La Niña events.

    The research was conducted by researchers at the Hobart based Centre for Southern Hemisphere Oceans Research, an international collaboration between CSIRO, Qingdao National Laboratory for Marine Science and Technology, the University of New South Wales, and the University of Tasmania.

    The National Environmental Science Programme’s Earth System and Climate Change Hub co-funded this research.

    See the full article here .

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    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

     
  • richardmitnick 11:01 am on July 13, 2017 Permalink | Reply
    Tags: , Climate Change, , , The calving of a massive iceberg in Antarctica is not a sign of climate doom but it may weaken the remainder of the Larsen C ice shelf, What the trillion-tonne Larsen C iceberg means   

    From COSMOS: “What the trillion-tonne Larsen C iceberg means” 

    Cosmos Magazine bloc

    COSMOS

    13 July 2017
    Adrian Luckman

    The calving of a massive iceberg in Antarctica is not a sign of climate doom, but it may weaken the remainder of the Larsen C ice shelf.

    One of the largest icebergs ever recorded has just broken away from the Larsen C Ice Shelf in Antarctica. Over the past few years I’ve led a team that has been studying this ice shelf and monitoring change. We spent many weeks camped on the ice investigating melt ponds and their impact – and struggling to avoid sunburn thanks to the thin ozone layer. Our main approach, however, is to use satellites to keep an eye on things.

    ESA/Sentinal 1


    The SENTINEL-1 mission comprises a constellation of two polar-orbiting satellites, operating day and night performing C-band synthetic aperture radar imaging, enabling them to acquire imagery regardless of the weather.

    We’ve been surprised by the level of interest in what may simply be a rare but natural occurrence. Because, despite the media and public fascination, the Larsen C rift and iceberg “calving” is not a warning of imminent sea level rise, and any link to climate change is far from straightforward. This event is, however, a spectacular episode in the recent history of Antarctica’s ice shelves, involving forces beyond the human scale, in a place where few of us have been, and one which will fundamentally change the geography of this region.

    1
    The iceberg would barely fit inside Wales. Adrian Luckman / MIDAS, Author provided

    Ice shelves are found where glaciers meet the ocean and the climate is cold enough to sustain the ice as it goes afloat. Located mostly around Antarctica, these floating platforms of ice a few hundred meters thick form natural barriers which slow the flow of glaciers into the ocean and thereby regulate sea level rise. In a warming world, ice shelves are of particular scientific interest because they are susceptible both to atmospheric warming from above and ocean warming from below.

    2
    The ice shelves of the Antarctic peninsula. Note Larsen A and B have largely disappeared. AJ Cook & DG Vaughan, 2014, CC BY-SA

    Back in the 1890s, a Norwegian explorer named Carl Anton Larsen sailed south down the Antarctic Peninsula, a 1,000km long branch of the continent that points towards South America. Along the east coast he discovered the huge ice shelf which took his name.

    For the following century, the shelf, or what we now know to be a set of distinct shelves – Larsen A, B, C and D – remained fairly stable. However the sudden disintegrations [Science] of Larsen A and B in 1995 and 2002 respectively, and the ongoing speed-up [Geophysical Research Letters] of glaciers which fed them, focused scientific interest on their much larger neighbour, Larsen C, the fourth biggest ice shelf in Antarctica.

    This is why colleagues and I set out in 2014 to study the role of surface melt [Cambridge Core] on the stability of this ice shelf. Not long into the project, the discovery by our colleague, Daniela Jansen, of [The Cryosphere]a rift growing rapidly through Larsen C, immediately gave us something equally significant to investigate.

    Nature at work

    The development of rifts and the calving of icebergs is part of the natural cycle of an ice shelf. What makes this iceberg unusual is its size – at around 5,800 km² it’s the size of a small US state. There is also the concern that what remains of Larsen C will be susceptible to the same fate as Larsen B, and collapse almost entirely.

    3
    Larsen B once extended hundreds of kilometres over the ocean. Today, one of its glaciers runs straight into the sea. Armin Rose / shutterstock

    Our work has highlighted significant similarities [Nature Communications] between the previous behaviour of Larsen B and current developments at Larsen C, and we have shown that stability may be compromised. Others, however, are confident that Larsen C will remain stable [Nature Climate Change].

    What is not disputed by scientists is that it will take many years to know what will happen to the remainder of Larsen C as it begins to adapt to its new shape, and as the iceberg gradually drifts away and breaks up [The Conversation]. There will certainly be no imminent collapse, and unquestionably no direct effect on sea level because the iceberg is already afloat and displacing its own weight in seawater.

    This means that, despite much speculation [On The Verge], we would have to look years into the future for ice from Larsen C to contribute significantly to sea level rise. In 1995 Larsen B underwenta similar calving event [Nature Communications]. However, it took a further seven years of gradual erosion of the ice-front before the ice shelf became unstable enough to collapse, and glaciers held back by it were able to speed up [Geophysical Research Letters], and even then the collapse process may have depended on the presence of surface melt ponds [Geophysical Research Letters].

    Even if the remaining part of Larsen C were to eventually collapse, many years into the future, the potential sea level rise is quite modest [Journal of Geophysical Research]. Taking into account only the catchments of glaciers flowing into Larsen C, the total, even after decades, will probably be less than a centimetre.

    Is this a climate change signal?

    This event has also been widely but over-simplistically linked to climate change [The Guardian]. This is not surprising because notable changes in the earth’s glaciers and ice sheets are normally associated with rising environmental temperatures. The collapses of Larsen A and B have previously been linked to regional warming [Letters to Nature], and the iceberg calving will leave Larsen C at its most retreated position in records going back over a hundred years.

    However, in satellite images from the 1980s, the rift was already clearly a long-established feature, and there is no direct evidence to link its recent growth to either atmospheric warming, which is not felt deep enough within the ice shelf, or ocean warming, which is an unlikely source of change given that most of Larsen C has recently been thickening [Science]. It is probably too early to blame this event directly on human-generated climate change.

    See the full article here .

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  • richardmitnick 8:05 am on May 8, 2017 Permalink | Reply
    Tags: , Climate Change, , , JISUNG PARK   

    From Harvard: “Making sense of climate costs” 

    Harvard University
    Harvard University

    April 28, 2017
    Colin Durrant

    1
    JISUNG PARK
    PhD Candidate in Economics
    Department of Economics
    Harvard University
    1805 Cambridge St
    Cambridge, MA 02138


    Video by Joe Sherman & Kai-Jae Wang

    Growing up between Lawrence, Kan., and Seoul, South Korea, gave Jisung Park different and distinct insights into how humans and nature intersect. Park recalls as a young boy spending every waking hour exploring the Kansas outdoors. Still a youngster when he moved to Seoul, living in its dense, urban environment revealed the toll that industrialization exacts on air and water quality.

    “I was always acutely aware of how human beings and society both affect and are affected by the natural environment,” said Park, who will graduate in May with a Ph.D. in economics from the Harvard Graduate School of Arts and Sciences. “Through experiencing the diversity of living in such different places, I grew to appreciate how much commonality there is in the basic humanity that we share.”

    His introductory economics class in high school gave him an entirely new lens with which to view the world — and think about studying it. In his undergraduate coursework at Columbia University, Park recognized that economics could be a tool for generating a greater understanding of the intersection of humans and nature.

    After his Rhodes Scholarship at Oxford University, Park joined the environmental economics program at Harvard to focus specifically on how the impacts of climate change will affect human productivity and economic health.

    “He has broken new ground with his research on weather, climate, and human capital, and will soon be moving on to a great career as an innovative scholar,” said Robert Stavins, the Albert Pratt Professor of Business & Government at Harvard Kennedy School and director of the Harvard Environmental Economics Program.

    Park says the motivation for his research is the fundamental disconnect in the public’s mind between recognizing climate change as a problem in the abstract sense but not being able to relate to the immediate impacts that may already be affecting the local community or region.

    “I was frustrated by this phenomenon that climate change was becoming an issue that, unless you are an ardent environmentalist, you weren’t allowed to comment about or care about,” said Park. “I wanted to use language and tools of economics to try and quantify the more direct impacts of climate change on human beings and human economy, to try and make it a little more real.”

    At a time when much attention is on rising sea levels and extreme weather events, Park eagerly took on the challenge of developing a greater understanding of the correlation between long-term economic vitality and rising temperatures due to global warming. As one of the first grantees of the President’s Climate Change Solutions Fund, Park explored the affect heat stress will have on labor productivity. According to Park, a year with 10 or more 90-degree-plus days in the United States could reduce income or output per capita by 3 percent. For context, he points to the fact that the Great Recession led to a percentage drop in GDP of that magnitude.

    Park says the grant opened doors and allowed him to engage with a wide variety of research institutions inside and outside of Harvard, including presenting his research to the World Bank and New York City government agencies.

    “It’s good to know there is institutional support for interdisciplinary research like this and that the support comes close to the top,” Park said. “It speaks to the direction in which the university wants to move in terms of priorities.”

    While at Harvard, Park presented what New York Times columnist Nicholas Kristof called a “clever new working paper” exploring the impact of hotter temperatures on student test scores and academic performance in New York City schools. He found that students taking a test on a 90-degree day relative to a 72-degree day have a 12 percent higher likelihood of failing. “You may not have seen a polar bear but you’ve definitely been in a classroom that was hot,” said Park.

    Park brought with him from Oxford a podcast project called Sense & Sustainability that started as a series of conversations with fellow students on topics related to sustainability. At Harvard, the organization took off, receiving a Student Sustainability Grant from the Harvard Office for Sustainability and expanding to a lively blog and weekly meetings of undergraduate and graduate fellows to share ideas.

    “It’s hard to have conversations across disciplines but also very rewarding, because it forces you to think outside your disciplinary focus or bias,” said Park. “It’s amazing how different our conceptions are of what sustainability is, and it opened me up to the diversity of ways one can conceptualize sustainability.”

    Park will complete a postdoc at Harvard Kennedy School on climate policy, then join the faculty at UCLA as part of a joint public policy and public health program, where he will continue his research into the environmental determinants of economic mobility.

    “The more you look at direct economic impacts of climate change, the more it begins to become clear it will be disadvantaged segments of society — both within countries but also across the world — that are going to be disproportionately affected,” said Park. “Climate change is the ultimate global public good problem, and that certainly is a motivation for me.”

    See the full article here .

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    Harvard University campus
    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 6:59 am on April 25, 2017 Permalink | Reply
    Tags: , Climate Change, , Nile River   

    From MIT: “Nile faces greater variability” 

    MIT News

    MIT Widget

    MIT News

    April 24, 2017
    David L. Chandler

    1
    Researchers at MIT have found that climate change may drastically increase the variability in Nile’s annual output.

    Climate change could lead to overall increase in river flow, but more droughts and floods, study shows.

    The unpredictable annual flow of the Nile River is legendary, as evidenced by the story of Joseph and the Pharaoh, whose dream foretold seven years of abundance followed by seven years of famine in a land whose agriculture was, and still is, utterly dependent on that flow. Now, researchers at MIT have found that climate change may drastically increase the variability in Nile’s annual output.

    Being able to predict the amount of flow variability, and even to forecast likely years of reduced flow, will become ever more important as the population of the Nile River basin, primarily in Egypt, Sudan, and Ethiopia, is expected to double by 2050, reaching nearly 1 billion. The new study, based on a variety of global climate models and records of rainfall and flow rates over the last half-century, projects an increase of 50 percent in the amount of flow variation from year to year.

    The study, published in the journal Nature Climate Change, was carried out by professor of civil and environmental engineering Elfatih Eltahir and postdoc Mohamed Siam. They found that as a result of a warming climate, there will be an increase in the intensity and duration of the Pacific Ocean phenomenon known as the El Niño/La Niña cycle, which they had previously shown is strongly connected to annual rainfall variations in the Ethiopian highlands and adjacent eastern Nile basins. These regions are the primary sources of the Nile’s waters, accounting for some 80 percent of the river’s total flow.

    The cycle of the Nile’s floods has been “of interest to human civilization for millennia,” says Eltahir, the Breene M. Kerr Professor of Hydrology and Climate. Originally, the correlation he showed between the El Niño/La Niña cycle and Ethiopian rainfall had been aimed at helping with seasonal and short-term predictions of the river’s flow, for planning storage and releases from the river’s many dams and reservoirs. The new analysis is expected to provide useful information for much longer-term strategies for placement and operation of new and existing dams, including Africa’s largest, the Grand Ethiopian Renaissance Dam, now under construction near the Ethiopia-Sudan border.

    While there has been controversy about that dam, and especially about how the filling of its reservoir will be coordinated with downstream nations, Eltahir says this study points to the importance of focusing on the potential impacts of climate change and rapid population growth as the most significant drivers of environmental change in the Nile basin. “We think that climate change is pointing to the need for more storage capacity in the future,” he says. “The real issues facing the Nile are bigger than that one controversy surrounding that dam.”

    Using a variety of global circulation models under “business as usual” scenarios, assuming that major reductions in greenhouse gas emissions do not take place, the study finds that the changing rainfall patterns would likely lead to an average increase of the Nile’s annual flow of 10 to 15 percent. That is, it would grow from its present 80 cubic kilometers per year to about 92 or more cubic kilometers per year averaged over the 21st century, compared to the 20th century average.

    The findings also suggest that there will be substantially fewer “normal” years, with flows between 70 and 100 cubic kilometers per year. There will also be many more extreme years with flows greater than 100, and more years of drought. (Statistically, the variability is measured as the standard deviation of the annual flow rates, which is the number that is expected to see a 50 percent rise).

    The pattern has in fact played out over the last two years — 2015, an intense El Niño year, saw drought conditions in the Nile basin, while the La Niña year of 2016 saw high flooding. “It’s not abstract,” Eltahir says. “This is happening now.”

    As with Joseph’s advice to Pharaoh, the knowledge of such likely changes can help planners to be prepared, in this case by storing water in huge reservoirs to be released when it is really needed.

    “Too often we focus on how climate change might influence average conditions, to the exclusion of thinking about variability,” says Ben Zaitchik, an associate professor of earth and planetary sciences at Johns Hopkins University, who was not involved in this work. “That can be a real problem for a place like the Eastern Nile basin, where average rainfall and streamflow might increase with climate change, suggesting that water will be plentiful. But if variability increases as well, then there could be as frequent or more frequent stress events, and significant planning — in infrastructure or management strategies — might be required to ensure water security.”

    Already, Eltahir’s earlier work on the El Niño/La Niña correlation with Nile flow is making an impact. “It’s used operationally in the region now in issuing seasonal flood forecasts, with a significant lead time that gives water resources engineers enough time to react. Before, you had no idea,” he says adding that he hopes the new information will enable even better long-term planning. “By this work, we at least reduce some of the uncertainty.”

    See the full article here .

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    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

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  • richardmitnick 10:45 am on April 20, 2017 Permalink | Reply
    Tags: , Climate Change,   

    From NYT: “Is It O.K. to Tinker With the Environment to Fight Climate Change?” 

    New York Times

    The New York Times

    APRIL 18, 2017
    JON GERTNER

    Scientists are investigating whether releasing tons of particulates into the atmosphere might be good for the planet. Not everyone thinks this is a good idea.

    1

    For the past few years, the Harvard professor David Keith has been sketching this vision: Ten Gulfstream jets, outfitted with special engines that allow them to fly safely around the stratosphere at an altitude of 70,000 feet, take off from a runway near the Equator. Their cargo includes thousands of pounds of a chemical compound — liquid sulfur, let’s suppose — that can be sprayed as a gas from the aircraft. It is not a one-time event; the flights take place throughout the year, dispersing a load that amounts to 25,000 tons. If things go right, the gas converts to an aerosol of particles that remain aloft and scatter sunlight for two years. The payoff? A slowing of the earth’s warming — for as long as the Gulfstream flights continue.

    Keith argues that such a project, usually known as solar geoengineering, is technologically feasible and — with a back-of-the-envelope cost of under $1 billion annually — ought to be fairly cheap from a cost-benefit perspective, considering the economic damages potentially forestalled: It might do good for a world unable to cut carbon-dioxide emissions enough to prevent further temperature increases later this century.

    What surprised me, then, as Keith paced around his Harvard office one morning in early March, was his listing all the reasons humans might not want to hack the environment. “Actually, I’m writing a paper on this right now,” he said. Most of his thoughts were related to the possible dangers of trying to engineer our way out of a climate problem of nearly unimaginable scientific, political and moral complexity. Solar geoengineering might lead to what some economists call “lock-in,” referring to the momentum that a new technology, even one with serious flaws, can assume after it gains a foothold in the market. The qwerty keyboard is one commonly cited example; the internal combustion engine is another. Once we start putting sulfate particles in the atmosphere, he mused, would we really be able to stop?

    Another concern, he said, is “just the ethics about messing with nature.” Tall, wiry and kinetic, with thinning hair and a thick beard that gives him the look of the backcountry skier he is, Keith proudly showed me the framed badge that his father, a biologist, wore when he attended the landmark United Nations Conference on the Human Environment in Stockholm in 1972. Now 53, Keith has taken more wilderness trips — hiking, rock climbing, canoeing — than he can properly recall, and for their recent honeymoon, he and his wife were dropped off by helicopter 60 miles from the nearest road in northern British Columbia. “It was quite rainy,” he told me, “and that ended up making it even better.” So the prospect of intentionally changing the climate, he confessed, is not just unpleasant — “it initially struck me as nuts.”

    It still strikes him as a moral hazard, to use a term he borrows from economics. A planet cooled by an umbrella of aerosol particles — an umbrella that works by reflecting back into space, say, 1 percent of the sun’s incoming energy — might give societies less incentive to adopt greener technologies and radically cut carbon emissions. That would be disastrous, Keith said. The whole point of geoengineering is not to give us license to forget about the buildup of CO₂. It’s to lessen the ill effects of the buildup and give us time to transition to cleaner energy.

    Beyond these conceivable dangers, though, a more fundamental problem lurks: Solar geoengineering simply might not work. It has been a subject of intense debate among climate scientists for roughly a decade. But most of what we know about its potential effects derives from either computer simulations or studies on volcanic eruptions like that of Mount Pinatubo in 1991, which generated millions of tons of sunlight-scattering particulates and might have cooled the planet by as much as 0.5 degrees Celsius, or nearly 1 degree Fahrenheit. The lack of support for solar geoengineering’s efficacy informs Keith’s thinking about what we should do next. Actively tinkering with our environment — fueling up the Gulfstream jets and trying to cool things down — is not something he intends to try anytime soon, if ever. But conducting research is another matter.

    A decade ago, when Keith was among the few American scientists to advocate starting a geoengineering research program, he was often treated at science conferences as an outlier. “People would sort of inch away or, really, tell me I shouldn’t be doing this,” he said. Geoengineering was seen as a scientific taboo and Keith its dark visionary. “The preconception was that I was some kind of Dr. Strangelove figure,” he told me — “which I didn’t like.”

    Attitudes appear to have changed over the past few years, at least in part because of the continuing academic debates and computer-modeling studies. The National Academy of Sciences endorsed the pursuit of solar geoengineering research in 2015, a stance also taken in a later report by the Obama administration. A few influential environmental groups, like the Natural Resources Defense Council and the Environmental Defense Fund, now favor research.

    In the meantime, Keith’s own work at Harvard has progressed. This month, he is helping to start Harvard’s Solar Geoengineering Research Program, a broad endeavor that begins with $7 million in funding and intends to reach $20 million over seven years. One backer is the Hewlett Foundation; another is Bill Gates, whom Keith regularly advises on climate change. Keith is planning to conduct a field experiment early next year by putting particles into the stratosphere over Tucson.

    The new Harvard program is not merely intent on getting its concepts out of the lab and into the field, though; a large share of its money will also be directed to physical and social scientists at the university, who will evaluate solar geoengineering’s environmental dangers — and be willing to challenge its ethics and practicality. Keith told me, “It’s really important that we have a big chunk of the research go to groups whose job will be to find all the ways that it won’t work.” In other words, the technology that Keith has long believed could help us ease our predicament — “the nuclear option” for climate, as one opponent described it to me, to be considered only when all else has failed — will finally be investigated to see whether it is a reasonable idea. At the same time, it will be examined under the premise that it may in fact be a very, very bad one.

    Climate change already presents a demoralizing array of challenges — melting ice sheets and species extinctions — but the ultimate severity of its impacts depends greatly on how drastically technology and societies can change over the next few decades. The growth of solar and wind power in recent years, along with an apparent decrease in coal use, suggest that the global community will succeed in curtailing CO₂ emissions. Still, that may not happen nearly fast enough to avert some dangerous consequences. As Keith likes to point out, simply reducing emissions doesn’t reverse global warming. In fact, even if annual global CO₂ emissions decrease somewhat, the total atmospheric CO₂ may continue to increase, because the gas is so slow to dissipate. We may still be living with damaging amounts of atmospheric carbon dioxide a half-century from now, with calamitous repercussions. The last time atmospheric CO₂ levels were as elevated as they are today, three million years ago, sea levels were most likely 45 feet higher, and giant camels roamed above the Arctic Circle.

    Recently, I met with Daniel Schrag, who is the head of the Harvard University Center for the Environment, an interdisciplinary teaching and research department. Schrag, who helped recruit Keith to Harvard, painted a bleak picture of our odds of keeping global temperatures from rising beyond levels considered safe by many climate scientists. When you evaluate the time scales involved in actually switching our energy systems to cleaner fuels, Schrag told me, “the really depressing thing is you start to understand why any of these kinds of projections — for 2030 or 2050 — are absurd.” He went on: “Are they impossible? No. I want to give people hope, too. I’d love to make this happen. And we have made a lot of progress on some things, on solar, on wind. But the reality is we haven’t even started doing the hard stuff.”

    Schrag described any kind of geoengineering as “at best an imperfect solution that is operationally extremely challenging.” Yet to Schrag and Keith, the political and technical difficulties associated with a rapid transition to a zero-carbon-emissions world make it sensible to look into geoengineering research. There happens to be a number of different plans for how to actually do it, however — including the fantastical (pumping seawater onto Antarctica to combat sea-level rise) and the impractical (fertilizing oceans with iron to foster the growth of algae, which would absorb more CO₂). Some proposals involve taking carbon out of the air, using either immense plant farms or absorption machines. (Keith is involved with such sequestration technology, which faces significant hurdles in terms of cost and feasibility.) Another possible approach would inject salt crystals into clouds over the ocean to brighten them and cool targeted areas, like the dying Great Barrier Reef. Still, the feeling among Keith and his colleagues is that aerosols sprayed into the atmosphere might be the most economically and technologically viable approach of all — and might yield the most powerful global effect.

    It is not a new idea. In 2000, Keith published a long academic paper on the history of weather and climate modification, noting that an Institute of Rainmaking was established in Leningrad in 1932 and that American engineers began a cloud-seeding campaign in Vietnam a few decades later. A report issued in 1965 by President Lyndon B. Johnson’s administration called attention to the dangers of increasing concentrations of CO₂ and, anticipating Keith’s research, speculated that a logical response might be to change the albedo, or reflectivity, of the earth. To Keith’s knowledge, though, there have been only two actual field experiments so far. One, by a Russian scientist in 2009, released aerosols into the lower atmosphere via helicopter and appears to have generated no useful data. “It was a stunt,” Keith says. Another was a modest attempt at cloud brightening a few years ago by a team at the Scripps Institution of Oceanography at the University of California, San Diego.

    Downstairs from Keith’s Harvard office, there is a lab cluttered with students fiddling with pipettes and arcane scientific instruments. When I visited in early March, Zhen Dai, a graduate student who works with Keith, was engaged with a tabletop apparatus, a maze of tubes and pumps and sensors, meant to study how chemical compounds interact with the stratosphere. For the moment, Keith’s group is leaning toward beginning its field experiments with ice crystals and calcium carbonate — limestone — that has been milled to particles a half-micron in diameter, or less than 1/100th the width of a human hair. They may eventually try a sulfur compound too. The experiment is called Scopex, which stands for Stratospheric Controlled Perturbation Experiment. An instrument that can disperse an aerosol of particles — say, several ounces of limestone dust — will be housed in a gondola that hangs beneath a balloon that ascends to 70,000 feet. The whole custom-built contraption, whose two small propellers will be steered from the ground, will also include a variety of sensors to collect data on any aerosol plume. Keith’s group will measure the sunlight-scattering properties of the plume and evaluate how its particles interact with atmospheric gases, especially ozone. The resulting data will be used by computer models to try to predict larger-scale effects.

    But whether a scientist should be deliberately putting foreign substances into the atmosphere, even for a small experiment like this, is a delicate question. There is also the difficulty of deciding on how big the atmospheric plumes should get. When does an experiment become an actual trial run? Ultimately, how will the scientists know if geoengineering really works without scaling it up all the way?

    Keith cites precedents for his thinking: a company that scatters cremation ashes from a high-altitude balloon, and jet engines, whose exhaust contains sulfates. But the crux of the problem that Harvard’s Solar Geoengineering Research Program wrestles with is intentionality. Frank Keutsch, a professor of atmospheric sciences at Harvard who is designing and running the Scopex experiments with Keith, told me: “This effort with David is very different from all my other work, because for those other field experiments, we’ve tried to measure the atmosphere and look at processes that are already there. You’re not actually changing nature.” But in this case, Keutsch agrees, they will be.

    During one of our conversations, Keith suggested that I try to flip my thinking for a moment. “What if humanity had never gotten into fossil fuels,” he posed, “and the world had gone directly to generating energy from solar or wind power?” But then, he added, what if in this imaginary cleaner world there was a big natural seep of a heat-trapping gas from within the earth? Such events have happened before. “It would have all the same consequences that we’re worried about now, except that it’s not us doing the CO₂ emissions,” Keith said. In that case, the reaction to using geoengineering to cool the planet might be one of relief and enthusiasm.

    In other words, decoupling mankind’s actions — the “sin,” as Keith put it, of burning fossil fuels — from our present dilemma can demonstrate the value of climate intervention. “No matter what, if we emit CO₂, we are hurting future generations,” Keith said. “And it may or may not be true that doing some solar geo would over all be a wise thing to do, but we don’t know yet. That’s the reason to do research.”

    There are risks, undeniably — some small, others potentially large and terrifying. David Santillo, a senior scientist at Greenpeace, told me that some modeling studies suggest that putting aerosols in the atmosphere, which might alter local climates and rain patterns and would certainly affect the amount of sunlight hitting the earth, could have a significant impact on biodiversity. “There’s a lot more we can do in theoretical terms and in modeling terms,” Santillo said of the Harvard experiments, “before anyone should go out and do this kind of proof-of-concept work.” Alan Robock, a professor of atmospheric sciences at Rutgers, has compiled an exhaustive list of possible dangers. He thinks that small-scale projects like the Scopex experiment could be useful, but that we don’t know the impacts of large-scale geoengineering on agriculture or whether it might deplete the ozone layer (as volcanic eruptions do). Robock’s list goes on from there: Solar geoengineering would probably reduce solar-electricity generation. It would do nothing to reduce the increasing acidification of the oceans, caused by seawater absorbing carbon dioxide. A real prospect exists, too, that if solar geoengineering efforts were to stop abruptly for any reason, the world could face a rapid warming even more dangerous than what’s happening now — perhaps too fast for any ecological adaptation.

    Keith is well aware of Robock’s concerns. He also makes the distinction that advocating research is not the same as advocating geoengineering. But the line can blur. Keith struck me as having a fair measure of optimism that his research can yield insights into materials and processes that can reduce the impacts of global warming while averting huge risks. For instance, he is already encouraged by computer models that suggest the Arctic ice cap, which has shrunk this year to the smallest size observed during the satellite era, could regrow under cooler conditions brought on by light-scattering aerosols. He also believes that the most common accusation directed against geoengineering — that it might disrupt precipitation patterns and lead to widespread droughts — will prove largely unfounded.

    But Keith is not trained as an atmospheric scientist; he’s a hands-on physicist-engineer who likes to take machinery apart. There are deep unknowns here. Keutsch, for one, seems uncertain about what he will discover when the group actually tries spraying particulates high above the earth. The reduction of sunlight could adversely affect the earth’s water cycle, for example. “It really is unclear to me if this approach is feasible,” he says, “and at this point we know far too little about the risks. But if we want to know whether it works, we have to find out.”

    Finally, what if something goes wrong either in research or in deployment? David Battisti, an atmospheric scientist at the University of Washington, told me, “It’s not obvious to me that we can reduce the uncertainty to anywhere near a tolerable level — that is, to the level that there won’t be unintended consequences that are really serious.” While Battisti thought Keith’s small Scopex experiment posed little danger — “The atmosphere will restore itself,” he said — he noted that the whole point of the Harvard researchers’ work is to determine whether solar geoengineering could be done “forever,” on a large-scale, round-the-clock basis. When I asked Battisti if he had issues with going deeper into geoengineering research, as opposed to geoengineering itself, he said: “Name a technology humans have developed that they haven’t used. I can’t think of any. So we can work on this for sure. But we are in this dilemma: Once we do develop this technology, it will be tempting to use it.”

    Suppose Keith’s research shows that solar geoengineering works. What then? The world would need to agree where to set the global thermostat. If there is no consensus, could developed nations impose a geoengineering regimen on poorer nations? On the second point, if this technology works, it would arguably be unethical not to use it, because the world’s poorest populations, facing drought and rising seas, may suffer the worst effects of a changing climate.

    In recent months, a group under the auspices of the Carnegie Council in New York, led by Janos Pasztor, a former United Nations climate official, has begun to work through the thorny international issues of governance and ethics. Pasztor told me that this effort will most likely take four years. And it is not lost on him — or anyone I spoke with in Keith’s Harvard group — that the idea of engineering our environment is taking hold as we are contemplating the engineering of ourselves through novel gene-editing technologies. “They both have an effect on shaping the pathway where human beings are now and where will they be,” says Sheila Jasanoff, a professor of science and technology studies at Harvard who sometimes collaborates with Keith. Jasanoff also points out that each technology potentially enables rogue agents to act without societal consent.

    This is a widespread concern. We might reach a point at which some countries pursue geoengineering, and nothing — neither costs nor treaties nor current technologies — can stop them. Pasztor sketched out another possibility to me: “You could even have a nightmare scenario, where a country decides to do geoengineering and another country decides to do counter-geoengineering.” Such a countermeasure could take the form of an intentional release of a heat-trapping gas far more potent than CO₂, like a hydrochlorofluorocarbon. One of Schrag’s main concerns, in fact, is that geoengineering a lower global temperature might preserve ecosystems and limit sea-level rise while producing irreconcilable geopolitical frictions. “One thing I can’t figure out,” he told me, “is how do you protect the Greenland ice sheet and still have Russia have access to its northern ports, which they really like?” Either Greenland and Siberia will melt, or perhaps both can stay frozen. You probably can’t split the difference.

    For the moment, and perhaps for 10 or 20 years more, these are mere hypotheticals. But the impacts of climate change were once hypotheticals, too. Now they’ve become possibilities and probabilities. And yet, as Tom Ackerman, an atmospheric scientist at the University of Washington, said at a recent discussion among policy makers that I attended in Washington: “We are doing an experiment now that we don’t understand.” He was not talking about geoengineering; he was observing that the uncertainty about the potential risks of geoengineering can obscure the fact that there is uncertainty, too, about the escalating disasters that may soon result from climate change.

    His comment reminded me of a claim made more than a half-century ago, long before the buildup of CO₂ in the atmosphere had become the central environmental and economic problem of our time. Two scientists, Roger Revelle and Hans Suess, wrote in a scientific paper, “Human beings are now carrying out a large-scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future.”

    If anything could sway a fence-sitter to consider whether geoengineering research makes sense, perhaps it is this. The fact is, we are living through a test already.

    See the full article here .

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  • richardmitnick 8:24 am on April 19, 2017 Permalink | Reply
    Tags: Climate Change, Climate Change Reroutes a Yukon River in a Geological Instant, , , , Kaskawulsh Glacier, , Slims River Valley   

    From NYT: “Climate Change Reroutes a Yukon River in a Geological Instant” 

    New York Times

    The New York Times

    APRIL 17, 2017
    JOHN SCHWARTZ

    1
    An aerial view of the ice canyon that now carries meltwater from the Kaskawulsh Glacier, on the right, away from the Slims River. “River piracy” refers to one river capturing and diverting the flow of another. Credit Dan Shugar/University of Washington-Tacoma

    In the blink of a geological eye, climate change has helped reverse the flow of water melting from a glacier in Canada’s Yukon, a hijacking that scientists call “river piracy.”

    This engaging term refers to one river capturing and diverting the flow of another. It occurred last spring at the Kaskawulsh Glacier, one of Canada’s largest, with a suddenness that startled scientists.

    A process that would ordinarily take thousands of years — or more — happened in just a few months in 2016.

    Much of the meltwater from the glacier normally flows to the north into the Bering Sea via the Slims and Yukon Rivers. A rapidly retreating and thinning glacier — accelerated by global warming — caused the water to redirect to the south, and into the Pacific Ocean.

    Last year’s unusually warm spring produced melting waters that cut a canyon through the ice, diverting more water into the Alsek River, which flows to the south and on into Pacific, robbing the headwaters to the north.

    2
    Jim Best, a researcher, measuring water levels on the lower-flowing Slims River in early September. Credit Dan Shugar/University of Washington-Tacoma

    The scientists concluded that the river theft “is likely to be permanent.”

    Daniel Shugar, an assistant professor of geoscience at the University of Washington-Tacoma, and colleagues described the phenomenon in a paper published on Monday in the journal Nature Geoscience.

    River piracy has been identified since the 19th century by geologists, and has generally been associated with events such as tectonic shifts and erosion occurring thousands or even millions of years ago. Those earlier episodes of glacial retreat left evidence of numerous abandoned river valleys, identified through the geological record.

    In finding what appears to be the first example of river piracy observed in modern times, Professor Shugar and colleagues used more recent technology, including drones, to survey the landscape and monitor the changes in the water coursing away from the Kaskawulsh Glacier.

    2
    Kaskawulsh glacier junction from air
    29 August 2014
    Author Gstest

    The phenomenon is unlikely to occur so dramatically elsewhere, Professor Shugar said in a telephone interview, because the glacier itself was forming a high point in the landscape and serving as a drainage divide for water to flow one way or another. As climate change causes more glaciers to melt, however, he said “we may see differences in the river networks and where rivers decide to go.”

    Changes in the flow of rivers can have enormous consequences for the landscape and ecosystems of the affected areas, as well as water supplies. When the shift abruptly reduced water levels in Kluane Lake, the Canadian Broadcasting Corporation reported, it left docks for lakeside vacation cabins — which can be reached only by water — high and dry.

    The riverbed of the Slims River basin, now nearly dry, experienced frequent and extensive afternoon dust storms through the spring and summer of last year, the paper stated.

    3
    The ice-walled canyon at the terminus of the Kaskawulsh Glacier, with recently collapsed ice blocks. This canyon now carries almost all meltwater from the toe of the glacier down the Kaskawulsh Valley and toward the Gulf of Alaska. Credit Jim Best/University of Illinois

    The impacts of climate change, like sea level rise or the shrinkage of a major glacier, are generally measured over decades, not months as in this case. “It’s not something you could see if you were just standing on the beach for a couple of months,” Professor Shugar said.

    The researchers concluded that the rerouted flow from the glacier shows that “radical reorganizations of drainage can occur in a geologic instant, although they may also be driven by longer-term climate change.” Or, as a writer for the CBC put it in a story about the phenomenon last year, “It’s a reminder that glacier-caused change is not always glacial-paced.”

    4
    Looking up the Slims River Valley, from the south end of Kluane Lake. The river used to flow down the valley from the Kaskawulsh glacier. (Sue Thomas)

    The underlying message of the new research is clear, said Dr. Shugar in a telephone interview. “We may be surprised by what climate change has in store for us — and some of the effects might be much more rapid than we are expecting.”

    The Nature Geoscience paper is accompanied by an essay from Rachel M. Headley, an assistant professor of geoscience and glacier expert at the University of Wisconsin-Parkside.

    “That the authors were able to capture this type of event almost as it was happening is significant in and of itself,” she said in an interview via email. As for the deeper significance of the incident, she said, “While one remote glacial river changing its course in the Yukon might not seem like a particularly big deal, glacier melt is a source of water for many people, and the sediments and nutrients that glacier rivers carry can influence onshore and offshore ecological environments, as well as agriculture.”

    Her article in Nature Geoscience concludes that this “unique impact of climate change” could have broad consequences. “As the world warms and more glaciers melt, populations dependent upon glacial meltwater should pay special attention to these processes.”

    Another glacier expert not involved in the research, Brian Menounos of the University of Northern British Columbia, said that while glaciers have waxed and waned as a result of natural forces over the eons, the new paper and his own research underscore the fact that the recent large-scale retreat of glaciers shows humans and the greenhouse gases they produce are reshaping the planet. “Clearly, we’re implicated in many of those changes,” he said.

    See the full article here .

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  • richardmitnick 7:38 am on March 30, 2017 Permalink | Reply
    Tags: , Climate Change, ,   

    From U Washington: “Tackling resilience: Finding order in chaos to help buffer against climate change” 

    U Washington

    University of Washington

    March 29, 2017
    Michelle Ma

    1
    Lotus flowers on a delta island on the outer reaches of the Mississippi delta, which is in danger of drastically shrinking or disappearing. The islands are actually quite resilient, as seen in part by the vegetation growth. Britta Timpane-Padgham/NWFSC

    “Resilience” is a buzzword often used in scientific literature to describe how animals, plants and landscapes can persist under climate change. It’s typically considered a good quality, suggesting that those with resilience can withstand or adapt as the climate continues to change.

    But when it comes to actually figuring out what makes a species or an entire ecosystem resilient ― and how to promote that through restoration or management ― there is a lack of consensus in the scientific community.

    A new paper by the University of Washington and NOAA’s Northwest Fisheries Science Center aims to provide clarity among scientists, resource managers and planners on what ecological resilience means and how it can be achieved. The study, published this month in the journal PLOS ONE, is the first to examine the topic in the context of ecological restoration and identify ways that resilience can be measured and achieved at different scales.

    “I was really interested in translating a broad concept like resilience into management or restoration actions,” said lead author Britta Timpane-Padgham, a fisheries biologist at Northwest Fisheries Science Center who completed the study as part of her graduate degree in marine and environmental affairs at the UW.

    “I wanted to do something that addressed impacts of climate change and connected the science with management and restoration efforts.”

    Timpane-Padgham scoured the scientific literature for all mentions of ecological resilience, then pared down the list of relevant articles to 170 examined for this study. She then identified in each paper the common attributes, or metrics, that contribute to resilience among species, populations or ecosystems. For example, genetic diversity and population density were commonly mentioned in the literature as attributes that help populations either recover from or resist disturbance.

    Timpane-Padgham along with co-authors Terrie Klinger, professor and director of the UW’s School of Marine and Environmental Affairs, and Tim Beechie, research biologist at Northwest Fisheries Science Center, grouped the various resilience attributes into five large categories, based on whether they affected individual plants or animals; whole populations; entire communities of plants and animals; ecosystems; or ecological processes. They then listed how many times each attribute was cited, which is one indicator of how well-suited a particular attribute is for measuring resilience.

    2
    The Kissimmee River in central Florida. This ecosystem-scale restoration project began two decades ago and is used as an example in the study. South Florida Water Management District

    “It’s a very nice way of organizing what was sort of a confused body of literature,” Beechie said. “It will at least allow people to get their heads around resilience and understand what it really is and what things you can actually measure.”

    The researchers say this work could be useful for people who manage ecosystem restoration projects and want to improve the chances of success under climate change. They could pick from the ordered list of attributes that relate specifically to their project and begin incorporating tactics that promote resilience from the start.

    “Specifying resilience attributes that are appropriate for the system and that can be measured repeatably will help move resilience from concept to practice,” Klinger said.

    or example, with Puget Sound salmon recovery, managers are asking how climate change will alter various rivers’ temperatures, flow levels and nutrient content. Because salmon recovery includes individual species, entire populations and the surrounding ecosystem, many resilience attributes are being used to monitor the status of the fish and recovery of the river ecosystems that support them.

    The list of attributes that track resilience can be downloaded and sorted by managers to find the most relevant measures for the type of restoration project they are tackling. It is increasingly common to account for climate change in project plans, the researchers said, but more foresight and planning at the start of a project is crucial.

    “The threat of climate change and its impacts is a considerable issue that should be looked at from the beginning of a restoration project. It needs to be its own planning objective,” Timpane-Padgham said. “With this paper, I don’t want to have something that will be published and collect dust. It’s about providing something that will be useful for people.”

    No external funding was used for this study.

    Download the spreadsheet to find the best resilience measures for your project (click on the second file in the carousal titled Interactive decision support table)

    See the full article here .

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  • richardmitnick 8:24 am on March 23, 2017 Permalink | Reply
    Tags: , Climate Change, Colorado, , , National Snow and Ice Data Center (NSIDC) in Boulder, Polar sea ice   

    From EarthSky: “Record low sea ice at both poles” 

    1

    EarthSky

    March 23, 2017
    Deborah Byrd

    Scientists at NASA and the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado said on March 22, 2017 that Arctic sea ice probably reached its 2017 maximum extent on March 7, and that this year’s maximum represents another record low. Meanwhile, on the opposite side of the planet, on March 3 sea ice around Antarctica hit its lowest extent ever recorded by satellites at the end of summer in the Southern Hemisphere. NASA called it:

    ” … a surprising turn of events after decades of moderate sea ice expansion.”

    Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland said:

    “It is tempting to say that the record low we are seeing this year is global warming finally catching up with Antarctica. However, this might just be an extreme case of pushing the envelope of year-to-year variability. We’ll need to have several more years of data to be able to say there has been a significant change in the trend.”

    Satellites have been continuously measuring sea ice in 1979, NASA said, and on February 13, the combined Arctic and Antarctic sea ice numbers were at their lowest point since.

    On February 13, total polar sea ice covered 6.26 million square miles (16.21 million square km). That’s 790,000 square miles (2 million square km) less than the average global minimum extent for 1981-2010 – the equivalent of having lost a chunk of sea ice larger than Mexico.

    1
    These line graphs plot monthly deviations and overall trends in polar sea ice from 1979 to 2017 as measured by satellites. The top line shows the Arctic; the middle shows Antarctica; and the third shows the global, combined total. The graphs depict how much the sea ice concentration moved above or below the long-term average. Arctic and global sea ice totals have moved consistently downward over 38 years. Antarctic trends are more muddled, but they do not offset the great losses in the Arctic. Image via Joshua Stevens/ NASA Earth Observatory.

    NASA explained the seasonal cycle of sea ice’s growth and shrinkage at Earth’s poles, and described specific weather events this year that led to the lower-than-average sea ice:

    The ice floating on top of the Arctic Ocean and surrounding seas shrinks in a seasonal cycle from mid-March until mid-September. As the Arctic temperatures drop in the autumn and winter, the ice cover grows again until it reaches its yearly maximum extent, typically in March. The ring of sea ice around the Antarctic continent behaves in a similar manner, with the calendar flipped: it usually reaches its maximum in September and its minimum in February.

    This winter, a combination of warmer-than-average temperatures, winds unfavorable to ice expansion, and a series of storms halted sea ice growth in the Arctic. This year’s maximum extent, reached on March 7 at 5.57 million square miles (14.42 million square km), is 37,000 square miles (97,00 square km) below the previous record low, which occurred in 2015, and 471,000 square miles (1.22 million square km) smaller than the average maximum extent for 1981-2010.

    Walt Meier added:

    “We started from a low September minimum extent. There was a lot of open ocean water and we saw periods of very slow ice growth in late October and into November, because the water had a lot of accumulated heat that had to be dissipated before ice could grow. The ice formation got a late start and everything lagged behind – it was hard for the sea ice cover to catch up.”

    NASA also said the Arctic’s sea ice maximum extent has dropped by an average of 2.8 percent per decade since 1979. The summertime minimum extent losses are nearly five times larger: 13.5 percent per decade. Besides shrinking in extent, the sea ice cap is also thinning and becoming more vulnerable to the action of ocean waters, winds and warmer temperatures.

    This year’s record low sea ice maximum extent might not necessarily lead to a new record low summertime minimum extent, since weather has a great impact on the melt season’s outcome, Meier said. But, he added:

    ” … it’s guaranteed to be below normal.”

    Meanwhile, in Antarctica, this year’s record low annual sea ice minimum of 815,000 square miles (2.11 million square km) was 71,000 square miles (184,000 square km) below the previous lowest minimum extent in the satellite record, which occurred in 1997. NASA explained:

    “Antarctic sea ice saw an early maximum extent in 2016, followed by a very rapid loss of ice starting in early September. Since November, daily Antarctic sea ice extent has continuously been at its lowest levels in the satellite record. The ice loss slowed down in February.”

    This year’s record low happened just two years after several monthly record high sea ice extents in Antarctica and decades of moderate sea ice growth. The Arctic and Antarctica are very different places; the Arctic is an ocean surrounded by northern continents, while Antarctica is a continent surrounded by ocean. In recent years, climage scientists have pointed to this difference to help explain why the poles were reacting to the trend of warming global temperatures differently.

    But many had said they expected sea ice to begin decreasing in Antarctica, as Earth’s temperatures continue to warm. Claire Parkinson, a senior sea ice researcher at Goddard, said on March 22:

    “There’s a lot of year-to-year variability in both Arctic and Antarctic sea ice, but overall, until last year, the trends in the Antarctic for every single month were toward more sea ice.

    Last year was stunningly different, with prominent sea ice decreases in the Antarctic.

    To think that now the Antarctic sea ice extent is actually reaching a record minimum, that’s definitely of interest.”

    3
    There’s no real reason Earth’s poles should react in the same way, or at the same rate, to global warming. A fundamental difference between Arctic (left) and Antarctic (right) regions is that the Arctic is a frozen ocean surrounded by continents, while the Antarctic is a frozen continent surrounded by oceanic waters. Map via NOAA/ climate.gov/ researchgate.net.

    Bottom line: Considering both poles in February 2017, Earth essentially lost the equivalent of a chunk of sea ice larger than Mexico, in contrast to the average global minimum for 1981-2010.

    See the full article here .

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  • richardmitnick 10:31 am on March 21, 2017 Permalink | Reply
    Tags: Climate Change, , Heavy California rains par for the course for climate change,   

    From Stanford: “Heavy California rains par for the course for climate change” 

    Stanford University Name
    Stanford University

    March 21, 2017
    Ker Than

    Here’s a question that Stanford climatologist Noah Diffenbaugh gets asked a lot lately: “Why did California receive so much rain lately if we’re supposed to be in the middle of a record-setting drought?”

    When answering, he will often refer the questioner to a Discover magazine story published in 1988, when Diffenbaugh was still in middle school.

    The article, written by veteran science writer Andrew Revkin, detailed how a persistent rise in global temperatures would affect California’s water system. It predicted that as California warmed, more precipitation would fall as rain rather than snow, and more of the snow that did fall would melt earlier in the season. This in turn would cause reservoirs to fill up earlier, increasing the odds of both winter flooding and summer droughts.

    “It is amazing how the state of knowledge in 1988 about how climate change would affect California’s water system has played out in reality over the last three decades,” said Diffenbaugh, a professor of Earth System Science at Stanford’s School of Earth, Energy & Environmental Sciences.

    Diffenbaugh, who specializes in using historical observations and mathematical models to study how climate change affects water resources, agriculture, and human health, sees no contradiction in California experiencing one of its wettest years on record right on the heels of a record-setting extended drought.

    “When you look back at the historical record of climate in California, you see this pattern of intense drought punctuated by wet conditions, which can lead to a lot of runoff,” said Diffenbaugh, who is also the Kimmelman Family senior fellow at the Stanford Woods Institute for the Environment. “This is exactly what state-of-the-art climate models predicted should have happened, and what those models project to intensify in the future as global warming continues.”

    That intensifying cycle poses risks for many Western states in the decades ahead. “In California and throughout the Western U.S., we have a water system that was designed and built more than 50 years ago,” Diffenbaugh said. “We are now in a very different climate, one where we’re likely to experience more frequent occurrences of hot, dry conditions punctuated by wet conditions. That’s not the climate for which our water system was designed and built.”

    Viewed through this lens, the recent disastrous flooding at Oroville Dam and the flooding in parts of San Jose as a result of the winter rains could foreshadow what’s to come. “What we’ve seen in Oroville and in San Jose is that not only is our infrastructure old, and not only has maintenance not been a priority, but we’re in a climate where we’re much more likely to experience these kinds of extreme conditions than we were 50 or 100 years ago,” Diffenbaugh said.

    It’s not too late, however, for California to catch up or even leap ahead in its preparations for a changing climate, scientists say. Diffenbaugh argues that there are plenty of “win-win” investment opportunities that will not only make Americans safer and more secure in the present, but also prepare for the future.

    California could, for example, boost its groundwater storage capacity, which research at Stanford shows to be a very cost-effective method for increasing water supply. This would have the dual benefit of siphoning off reservoirs at risk of flooding and storing water for future dry spells. It would also help jurisdictions reach the groundwater sustainability targets mandated by the state’s Sustainable Groundwater Management Act.

    Diffenbaugh also sees opportunities to increase water recycling throughout the state. “Our technology has advanced to a point now where we can create clean, safe water from waste water,” he said. “In fact, work here at Stanford shows that this can now be done using the organic matter in the waste water to provide an energy benefit.”

    Diffenbaugh stresses that reaping the full benefits of these investments requires a recognition that the climate of California and the West has changed, and will continue to change in the future as long as global warming continues.

    See the full article here .

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  • richardmitnick 11:42 am on March 16, 2017 Permalink | Reply
    Tags: , Climate Change, , , Great Barrier Reef is dying   

    From EarthSky: “Great Barrier Reef is dying” 

    1

    EarthSky

    March 16, 2017
    Deborah Byrd

    1
    Bleached coral in 2016 on the northern Great Barrier Reef. Image via Terry Hughes et al./Nature.

    Great Barrier Reef – the world’s largest reef system – is being increasingly affected by climate change, according to the authors of a cover story in the March 15, 2017 issue of the peer-reviewed journal Nature. Large sections of the reef are now dead, these scientists report. Marine biologist Terry Hughes of the ARC Center of Excellence for Coral Reef Studies led a group that examined changes in the geographic footprint – that is, the area affected – of mass bleaching events on the Great Barrier Reef over the last two decades. They used aerial and underwater survey data combined with satellite-derived measurements of sea surface temperature. Editors at Nature reported:

    “They show that the cumulative footprint of multiple bleaching events has expanded to encompass virtually all of the Great Barrier Reef, reducing the number and size of potential refuges [for fish and other creatures that live in the reef]. The 2016 bleaching event proved the most severe, affecting 91% of individual reefs.”

    2
    The NY Times published this map on March 15, 2017, based on information from the ARC Centre of Excellence for Coral Reef Studies. It shows that individual reefs in each region of the Great Barrier Reef lost different amounts of coral in 2016. Numbers show the range of loss for the middle 50% of observations in each region. Study authors told the NY Times this level of destruction wasn’t expected for another 30 years.

    Hughes and colleagues said in their study [Nature]:

    “During 2015–2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s …

    The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016.

    Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.”

    According to the website CoralWatch.org:

    Many stressful environmental conditions can lead to bleaching, however, elevated water temperatures due to global warming have been found to be the major cause of the massive bleaching events observed in recent years. As the sea temperatures cool during winter, corals that have not starved may overcome a bleaching event and recover their [symbiotic dinoflagellates (algae)].

    However, even if they survive, their reproductive capacity is reduced, leading to long-term damage to reef systems.

    4
    In March 2016, researchers could see bleached coral in the northern Great Barrier Reef from the air. Image via James Kerry/ARC Center of Excellence for Coral Reef Studies.

    Bottom line: Authors of a cover story published on March 15, 2017 in the journal Nature called for action to curb warming, to help save coral reefs.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
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