Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Tag Archive: sea level rise

  1. ‘Extreme’ Changes Underway in Some of Antarctica’s Biggest Glaciers

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    • The grounding line, where the glaciers become floating ice shelves, is receding as much as 600 feet per year, bolstering fears of a worst-case Antarctic meltdown scenario, with global sea level rising 10 feet by 2100.
    • Eight of the frozen continent’s 65 major ice streams had retreated by more than 410 feet per year—five times the average rate of retreat since the end of the last ice age. The grounding line of some of the glaciers emptying into the Amundsen Sea had retreated by up to 600 feet per year.
  2. Dramatic increase in flooding on East Coast roads

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    • roads along the East Coast have experienced a 90 percent increase in flooding over the past 20 years

    March 28, 2018 University of New Hampshire read full ScienceDaily article here

    Researchers have found that in the past 20 years roads along the East Coast have experienced a 90 percent increase in flooding — often making the roads in these communities impassable, causing delays, as well as stress, and impacting transportation of goods and services.

    ….They estimate that this causes over 100 million hours of delays each year for drivers on those roads and that number could rise to more than 3.4 billion hours by 2100. By the middle of the century (2056 -2065), they predict nuisance flooding could occur almost daily at specific sites along the shores of Connecticut, New Jersey, Maryland, the District of Columbia, North Carolina, and Florida under an intermediate sea-level-rise scenario….

    Photo: Roads closed due to high tide floods in Portsmouth, N.H.
    Credit: Lisa Graichen/UNH

    Jennifer M. Jacobs, Lia R. Cattaneo, William Sweet, Theodore Mansfield. Recent and Future Outlooks for Nuisance Flooding Impacts on Roadways on the US East Coast. Transportation Research Record: The Journal of the Transportation Research Board, 2018; 036119811875636 DOI: 10.1177/0361198118756366

  3. Sinking land will exacerbate flooding from sea level rise in Bay Area

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    • Subsidence combined with sea level rise around San Francisco Bay could double flood-risk area

    March 7, 2018 University of California – Berkeley

    …A new study of subsidence around San Francisco Bay shows that for conservative estimates of sea level rise, twice the area is in danger of flooding by 2100 than previously thought. Some landfill is sinking 10 mm per year, threatening the airport and parts of Silicon Valley…

    [Note: The USGS CoSMoS modeling that underlies the Our Coast Our Future tool (developed by Point Blue, USGS, and others) accounts for uncertainty in spatially variable vertical land motion for the SF Bay Region– see “Flood Potential” topic in section 1 in OCOF flood map. The vertical land motion component that went into understanding the uncertainty of the flood mapping for original SF Bay OCOF work (image below) was developed by the same author, Roland Burgmann, through the NOAA’s National Estuarine Research Reserve. This new paper is a refinement of these data.]

    “We are only looking at a scenario where we raise the bathtub water a little bit higher and look where the water level would stand,” said senior author Roland Bürgmann, a UC Berkeley professor of earth and planetary science. “But what if we have a 100-year storm, or king tides or other scenarios of peak water-level change? We are providing an average; the actual area that would be flooded by peak rainfall and runoff and storm surges is much larger.”

    …”Accurately measuring vertical land motion is an essential component for developing robust projections of flooding exposure for coastal communities worldwide,” said Patrick Barnard, a research geologist with the U.S. Geological Survey in Menlo Park [and OCOF PI]. “This work is an important step forward in providing coastal managers with increasingly more detailed information on the impacts of climate change, and therefore directly supports informed decision-making that can mitigate future impacts.”….

    Sf Bay Flood potential

  4. Sea level rise urgently requires new forms of decision making- social choice model

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    • A new decision-making model — a social choice model — adds additional criteria to the economic– including environmental, cultural, or recreational, through public discussion.
    • By using a social choice model, the city would have a richer source of options and ideas to work with. Something that puts all available options on the table and requires that they be evaluated with a more comprehensive and long-term perspective.
    • In the research study, the option of relocating coastal infrastructure would likely provide the most benefit to the city in the long-run, as it would protect both the beach and vulnerable infrastructure.

    March 6, 2018 Lund University read full ScienceDaily article here

    US cities facing sea level rise need to look beyond traditional strategies for managing issues such as critical erosion and coastal squeeze, according to new research. Civil society initiatives must now play a crucial role in adapting society to climate change, the study argues.

    The three options that have been considered in Flagler Beach are: constructing a sea wall, beach re-nourishment, or relocation of coastal infrastructure…

    ….The study instead proposes, that from a scientific, environmental and societal perspective, it is the option of relocating coastal infrastructure that would likely provide the most benefit to the city in the long-run, as it would protect both the beach and vulnerable infrastructure. Relocation has been promoted as the only viable long-term sustainable approach to beach management by coastal scientists; since it would provide for the beach to naturally adapt to sea level rise. Implementing this solution, however, is not likely to be an easy task.

    …The study argues that a new decision-making model — a social choice model — could be one way forward. By taking primarily economic criteria into account, a wide variety of other concerns citizens have, including those of far-away tax payers and future generations, are left out. Therefore additional criteria, whether environmental, cultural, or recreational, should be identified through reasonable public discussion.

    This would require not only more effective collaboration between federal, state and local governments, but also the ceding of more decision-making power to citizens and civil society organizations.

    “By using a social choice model, the city would have a richer source of options and ideas to work with. Something that puts all available options on the table and requires that they be evaluated with a more comprehensive and long-term perspective.”…

  5. Actions today will decide Antarctic ice sheet loss and sea level rise

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    • Each 5-year delay – a peak in 2025 instead of 2020, for example – most likely adds 20 cm of sea level rise by 2300, and could potentially add a full meter due to the uncertainty associated with the large ice sheets

    March 1 2018 by dana1981  read full SkepticalScience Post here

    A new study published in Nature looks at how much global sea level will continue to rise even if we manage to meet the Paris climate target of staying below 2°C hotter than pre-industrial temperatures. The issue is that sea levels keep rising for several hundred years after we stabilize temperatures, largely due to the continued melting of ice sheets in Antarctica and Greenland from the heat already in the climate system.

    The study considered two scenarios. In the first, human carbon pollution peaks somewhere between 2020 and 2035 and falls quickly thereafter, reaching zero between 2035 and 2055 and staying there. Global temperatures in the first scenario peak at and remain steady below 2°C. In the second scenario, we capture and sequester carbon to reach net negative emissions (more captured than emitted) between 2040 and 2060, resulting in falling global temperatures in the second half of the century….

    …The study also shows that it’s critical that our carbon pollution peaks soon. Each 5-year delay – a peak in 2025 instead of 2020, for example – most likely adds 20 cm of sea level rise by 2300, and could potentially add a full meter due to the uncertainty associated with the large ice sheets

    Another new study, published in the Proceedings of the National Academy of Sciences, found that sea level rise has been accelerating. If the rate of acceleration continues – which the lead author notes is a conservative estimate – we would see an additional 65 cm (close to a meter above pre-industrial sea level) of sea level rise by 2100.

    Yet another new study published in The Cryosphere using satellite data found that while the East Antarctic Ice Sheet has remained stable in recent years, ice loss from the West Antarctic Ice Sheet has accelerated….

    Matthias Mengel et al. Committed sea-level rise under the Paris Agreement and the legacy of delayed mitigation action Nature Communications volume 9, Article number: 601 (2018) doi:10.1038/s41467-018-02985-8

  6. Sea level rise accelerating per 25 years of observational satellite data

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    February 12, 2018 University of Colorado at Boulder  read full ScienceDaily article here

    Global sea level rise is not cruising along at a steady 3 mm per year, it’s accelerating a little every year, like a driver merging onto a highway, according to a powerful new assessment led by CIRES Fellow Steve Nerem. He and his colleagues harnessed 25 years of satellite data to calculate that the rate is increasing by about 0.08 mm/year every year — which could mean an annual rate of sea level rise of 10 mm/year, or even more, by 2100….

    From InsideClimateNews:

    …Congress may be catching on, said Rob Moore, a policy analyst with the Natural Resources Defense Council. Disaster relief provisions in the federal spending bill approved on Friday include significant funding to make communities more resilient to the long-term threat of climate change….

    ….Some scientists also warn that a rapid disintegration of Antarctica’s ice sheets could push sea level up much faster and higher, by as much as 4 to 10 feet by 2100. “The largest uncertainty is really Antarctica,” said Ingo Sasgen, a climate researcher at the Alfred Wegener Institute in Germany. “The big question for planners is how to deal with the possible extremes.”

    The last time Earth was as warm as it is now was about 125,000 years ago, and we know sea level was 6 meters higher than it is today, Nerem said. “The big question is, now long will it take to get there.”

    R. S. Nerem, B. D. Beckley, J. T. Fasullo, B. D. Hamlington, D. Masters and G. T. Mitchum. Climate-change–driven accelerated sea-level rise detected in the altimeter era. PNAS, 2018 DOI: 10.1073/pnas.1717312115

     

    Average Sea Level Rise Over 25 Years, 1993-2017

     

  7. California cliffs identified that are at risk of collapse; erosion rates will increase with sea level rise

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    • A new study analyzes cliff erosion throughout California and provides a new hazard index for determining which areas are at most risk.

    December 21, 2017 UC San Diego read full ScienceDaily article here

    ….Actively eroding cliffs make up the majority of the California coastline, and sudden landslides and collapses have caused injuries and several fatalities in recent years. In addition, eroding cliffs currently threaten highways, houses, businesses, military bases, parks, power plants, and other critical facilities — all in all billions of dollars of development.

    Research suggests that erosion rates will increase as sea level rises, further exacerbating these problems….

    ….The study…. provides accurate erosion rates for 680 miles of the California coast, from the US-Mexico border to Bodega Head in Sonoma County. It identifies areas that have eroded faster than others, and introduces a new experimental hazard scale to identify areas that may be at greater risk of impending collapse. It is the first such large-scale study in California using LiDAR data — laser elevation data recorded in aerial surveys — which were used to create detailed 3D elevation maps….

    Adam P. Young. Decadal-scale coastal cliff retreat in southern and central California. Geomorphology, 2018; 300: 164 DOI: 10.1016/j.geomorph.2017.10.010

  8. Changing climate, changing cities: Jakarta Is Sinking So Fast, It Could End Up Underwater in 10 Years

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  9. Anticipate sea level rise extremes now: we could end up with 8 ft by 2100 but won’t know until after 2050 per new study

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    • The use of a physical model indicates that emissions matter more for 21st century sea-level change than previous projections showed
    • “We could end up with 8 feet of sea level-rise in 2100, but we’re not likely to have clear evidence for that by 2050.”
    • The world can make lower sea-level rise outcomes much more likely by meeting the 2015 Paris Agreement goal of bringing net greenhouse gas emissions to zero in the second half of this century, the study shows.
    • Another study found that a 1.5 degrees Celsius world would reach a peak rate of sea-level rise about 0.7 inches per decade less than in a 2 degrees Celsius world — a potentially life-saving reduction for some vulnerable coastal ecosystems.

    December 13, 2017 Rutgers University Read full ScienceDaily article here

    The Earth faces a broad range of possible outcomes with climate change. At the less severe end, 2 feet of global-average sea-level rise by 2100 would submerge land that’s currently home to about 100 million people. Toward the high end, 6 feet of rise would swamp the current homes of more than 150 million. Either scenario would have drastic impacts in New Jersey and other coastal states.

    But the study, published today in Earth’s Future, finds that scientists won’t be able to determine, based on measurements of large-scale phenomena like global sea level and Antarctic mass changes, which scenario the planet faces until the 2060s. So coastal communities should have flexible contingency plans for a broad range of outcomes by 2100 and beyond, the study concludes….

    …The world can make lower sea-level rise outcomes much more likely by meeting the 2015 Paris Agreement goal of bringing net greenhouse gas emissions to zero in the second half of this century, the study shows. Scientists may also become able to distinguish between different scenarios sooner by studying the physics of local ice-sheet changes and refining reconstructions of changes during warm periods in geological history.

    Sea-level rise poses a potentially existential risk to Earth’s low-lying cities and coastal areas, so any projected increase needs to be taken seriously by planners, environmental officials, property owners and others

    …Kopp is also a co-author of another study, led by Tufts University researcher Klaus Bittermann and published today in Environmental Research Letters, assessing the sea-level rise benefits of achieving the Paris Agreement’s more ambitious 1.5 degrees Celsius (2.7 degrees Fahrenheit) temperature target rather than its headline 2 degrees Celsius (3.6 degrees Fahrenheit) target. That study found that a 1.5 degrees Celsius world would reach a peak rate of sea-level rise about 0.7 inches per decade less than in a 2 degrees Celsius world — a potentially life-saving reduction for some vulnerable coastal ecosystems.

    Kopp et al. Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future (AGU). DOI: 10.1002/2017EF000663

    Summary: Recent ice-sheet modeling papers have introduced new physical mechanisms—specifically the hydrofracturing of ice shelves and the collapse of ice cliffs—that can rapidly increase ice-sheet mass loss from a marine-based ice-sheet, as exists in much of Antarctica. This paper links new Antarctic model results into a sea-level rise projection framework to examine their influence on global and regional sea-level rise projections and their associated uncertainties, the potential impact of projected sea-level rise on areas currently occupied by human populations, and the implications of these projections for the ability to constrain future changes from present observations. Under a high greenhouse gas emission future, these new physical processes increase median projected 21st century GMSL rise from ∼80 to ∼150 cm. Revised median RSL projections for a high-emissions future would, without protective measures, by 2100 submerge land currently home to more than 153 million people. The use of a physical model indicates that emissions matter more for 21st century sea-level change than previous projections showed. Moreover, there is little correlation between the contribution of Antarctic to sea-level rise by 2050 and its contribution in 2100 and beyond, so current sea-level observations cannot exclude future extreme outcomes.

  10. CA case studies on natural shoreline infrastructure for coastal resilience: NEW from NOAA, TNC, Point Blue and ESA

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    November, 2017 by Jenna Judge, NOAA Sentinal Site Cooperative (reprinted from an email)

    Case Studies of Natural Shoreline Infrastructure in California,” conducted with support from California’s Fourth Climate Change Assessment and led by Jenna Judge of the NOAA Sentinel Site Cooperative, in partnership with The Nature Conservancy, Point Blue, and Environmental Science Associates.

    Sea level rise and associated flooding will threaten nearly $100 billion worth of property along the California coast by 2100, and there is no question that coastal landowners and planners will act to protect their assets from these losses. In the absence of compelling reasons or guidance to do otherwise, they will overwhelmingly default to the industry standard – specifically, the construction of coastal armoring (seawalls, revetments, dikes, and levees).

    An alternative to coastal armoring is natural infrastructure, which has been shown to be a cost-effective approach to mitigating risk of floods, storms and sea level rise in many places. Natural infrastructure enhances the ability of natural systems to respond to sea level rise and migrate landward, ensuring their survival. In turn, these systems provide co-benefits for coastal communities: coastal ecosystems can serve as protective buffers against sea level rise and storm events while continuing to provide access, recreation opportunities, and other social benefits.

    Jenner Headlands, by Ryan DiGaudio, Point BlueJenner Headlands, Sonoma County, CA. Photo by Ryan DiGaudio/Point Blue

    In spite of the well-known advantages of natural infrastructure, property owners continue to default to coastal armoring to protect their assets. There are a number of obstacles in deploying natural infrastructure that result in this preference for coastal armoring, but among them is a documented lack of familiarity with what natural infrastructure is and how it works.

    This detailed case studies report is designed to fill this awareness gap. The case studies, highlighting projects ranging from sediment augmentation in Seal Beach to dune restoration in Humboldt, are designed to give coastal managers a sense of the breadth of approaches to coastal adaptation and what it takes to plan, permit, implement, and monitor them.

    The report can be accessed here (pdf).

    [NOTE: Point Blue scientists are also collaboratively addressing coastal resilience on a national scale with the National Fish and Wildlife Foundation, NOAA, US Army Corps of Engineers, the National Environmental Modeling and Analysis Center, and NatureServe.  We are addressing questions such as: How do we know which coastal species and which habitats will be most threatened by climate change impacts? Where will restoration and other habitat enhancement projects also benefit human communities?

    On December 13th and 14th we’re helping to bring coastal managers and stakeholders together to identify vulnerable species and areas, missing data sets, and priority restoration areas. Learn more here. Help us spread the word by sharing with coastal stakeholders you know.]