Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Category Archive: Adaptation and Nature-based Solutions

  1. Review of research and future priorities to inform CA’s GHG emissions reductions plan: Agriculture and working lands

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    Byrnes R, Eviner V, Kebreab E, Horwath W, Jackson L, Jenkins B, Kaffka S, Kerr A, Lewis J, Mitloehner F, Mitchell J, Scow K, Steenwerth K, Wheeler S. 2017. Review of research to inform California’s climate scoping plan: Agriculture and working lands. California Agriculture 71(3):160-168. https://doi.org/10.3733/ca.2017a0031.

    This article grew out of conversations with state agencies concerning the need for a review of the current evidence base to inform emissions-reduction modeling and revisions to the state Climate Change Scoping Plan (CARB 2017b), which specifies net emissions reduction targets for each major sector of the California economy (table 1). It is important to note that the Scoping Plan states that work will continue through 2017 to estimate the range of potential sequestration benefits from natural and working lands (including agriculture and rangelands).

    Abstract: Agriculture in California contributes 8% of the state’s greenhouse gas (GHG) emissions. To inform the state’s policy and program strategy to meet climate targets, we review recent research on practices that can reduce emissions, sequester carbon and provide other co-benefits to producers and the environment across agriculture and rangeland systems. Importantly, the research reviewed here was conducted in California and addresses practices in our specific agricultural, socioeconomic and biophysical environment. Farmland conversion and the dairy and intensive livestock sector are the largest contributors to GHG emissions and offer the greatest opportunities for avoided emissions. We also identify a range of other opportunities including soil and nutrient management, integrated and diversified farming systems, rangeland management, and biomass-based energy generation. Additional research to replicate and quantify the emissions reduction or carbon sequestration potential of these practices will strengthen the evidence base for California climate policy.

    A no-till field with residue from a winter crop of triticale. Management practices can increase total soil carbon, but the magnitude and persistence of sequestration is dependent on inputs and time.A no-till field with residue from a winter crop of triticale. Management practices can increase total soil carbon, but the magnitude and persistence of sequestration is dependent on inputs and time.

    …soil carbon sequestration is highly dependent on annual carbon inputs and if management changes, soil carbon is prone to return to the atmosphere.Given the reality of inconsistent management, rates of soil carbon sequestration that can be expected in row crop systems practice are perhaps 10% of the values seen in these long-term research trials, namely in the range of 0.014 to 0.03 tons per acre per year (unpublished data). If soil carbon sequestration and storage are priorities, management plans and incentive structures should account for the wide variability of California soils and the need for consistent management over time.

    While any single soil and nutrient management practice may have limited impact on GHG emissions, many have well-documented co-benefits, including reductions in erosion, improved air quality (Madden et al. 2008), reduced farm machinery fossil fuel use (West et al. 2002), reduced nitrogen leaching (Poudel et al. 2002), enhanced water infiltration and reduced soil water evaporation (Mitchell 2012), and increased carbon stocks below the root zone to improve carbon sequestration (Suddick et al. 2013)

    The research above points to the magnitude of opportunity from alternative rangeland practices and the need to identify socioeconomic opportunities and barriers to greater participation in range management incentive programs

    Priorities for future research

    Here we identify cross-cutting priorities that will enable scaling and, equally important, the integration of multiple practices to achieve more substantial progress toward both climate change mitigation and adaption in agriculture. Among the priorities we identify are:

    • Replication and longer-term studies to quantify the GHG mitigation or carbon sequestration associated with specific practices.
    • Quantification of synergies from stacking multiple practices over time and scale (e.g., field to region) to address efficacies for carbon sequestration, emissions reductions and nitrogen use.
    • Characterization and, where possible, quantification of co-benefits (water, economic, air quality) from soil management practices, livestock grazing and manure management, and biomass-based fuels.
    • Using social and political science research to identify socioeconomic factors that either create barriers or promote adoption of practices (e.g., social networks, gender, social norms, and values).
    • Validation of metrics for soil health parameters, including calibration of models for California conditions that may be used to estimate metrics, such as:
    • Potential use of remote sensing to measure adoption of specific practices outlined above.
    • Validation and/or calibration of models for estimating GHG emissions, including the crop and soil process model, DAYCENT (Del Grosso et al. 2005), and the USDA’s whole farm and ranch carbon and GHG accounting system, which uses the DAYCENT model (COMET-Farm; http://cometfarm.nrel.colostate.edu/ ).
    • Research into the design of incentives (such as payments, tax credits, low interest loans, etc.) to leverage private investment and promote adoption of emissions-reduction practices in agriculture.
    • Development of metrics and sampling or survey tools to assess adoption of emissions-reduction practices.
    • Development of farmer demonstration and evaluation networks for scaling up the adoption of improved performance systems.
  2. Forest grazing counteracts the effectiveness of trees to reduce flood risk

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    • Planting trees can reduce flood risk, but a high intensity forest land use, such as grazing, can counteract the positive effect
    • Infiltration rates were between ten and a hundred times higher under trees, when the forested area remained relatively undisturbed, compared with adjacent pasture
    • Forest buffer zones, with restricted access, strategically placed to intercept surface runoff before it reaches the stream may be more effective than larger scale planting when the forested areas are used for other purposes

    October 10, 2017 Lancaster University read full ScienceDaily article here

    As the frequency and severity of flooding becomes an increasing problem, land managers are turning to natural flood management measures, such as tree planting, to reduce the risk. When rainfall exceeds the rate at which water can enter the soil it flows rapidly over the land’s surface into streams and rivers. Trees can help to reduce the risk of surface runoff by increasing the number of large pores in the soil through which water can drain more easily. Land use, such as grazing, also affects the soil’s ability to absorb water; however, while the effect of land use on surface runoff has been well studied in grasslands, little is known about the effect of land use in forests.

    …Researchers found that infiltration rates were between ten and a hundred times higher under trees, when the forested area remained relatively undisturbed, compared with adjacent pasture. Where sheep were allowed to graze under the trees there was no observable difference from the pasture.

    They also compared forest types — conifer forest planted with Scots Pine and broadleaved forest planted with sycamore — and found that infiltration rates were significantly higher under Scots Pine than under sycamore, but only when the forest was ungrazed…

    …”Tree planting can make an important contribution to flood risk management, but forest buffer zones, with restricted access, strategically placed to intercept surface runoff before it reaches the stream may be more effective than larger scale planting when the forested areas are used for other purposes.”…

    K.R.Chandler, C.J.Stevens, A.Binley, A.M.Keith. Influence of tree species and forest land use on soil hydraulic conductivity and implications for surface runoff generation. Geoderma, 2017 DOI: 10.1016/j.geoderma.2017.08.011

  3. What would an entirely flood-proof city look like? From China to New Jersey

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    • As the recent floods from Bangladesh to Texas show, it’s not just the unprecedented magnitude of storms that can cause disaster: it’s urbanisation.
    • From sponge cities in China to ‘berms with benefits’ in New Jersey and floating container classrooms in the slums of Dhaka, we look at a range of projects that treat storm water as a resource rather than a hazard.

    by Sophie Knight Sept. 25 2017 read full GuardianUK article here

    They call it “pave, pipe, and pump”: the mentality that has dominated urban development for over a century. Along with the explosion of the motorcar in the early 20th century came paved surfaces. Rainwater – instead of being sucked up by plants, evaporating, or filtering through the ground back to rivers and lakes – was suddenly forced to slide over pavements and roads into drains, pipes and sewers. Their maximum capacities are based on scenarios such as 10-year storms. And once they clog, the water – with nowhere else to go – simply rises.

    The reality of climate change and more frequent and intense downpours has exposed the hubris of this approach. As the recent floods from Bangladesh to Texas show, it’s not just the unprecedented magnitude of storms that can cause disaster: it’s urbanisation.

    …With climate change both a reality and threat, many architects and urbanists are pushing creative initiatives for cities that treat stormwater as a resource, rather than a hazard….

    …In China, the government has commissioned the construction of 16 “Sponge Cities” to pilot solutions for the freshwater scarcity and flooding suffered in many cities as a result of rapid urbanisation. Chicago architectural firm UrbanLab was commissioned to design the masterplan for Yangming Archipelago in Hunan province: a new centre within the larger city of Changde, devised as a “new model for the future”.

    The area, a low-lying land river basin that experiences heavy rainfall, is regularly flooded. Instead of incorporating defences against water, UrbanLab put space for it to flow at the centre of its urban plan, putting major buildings on islands in an enormous central lake. Canal-lined streets that UrbanLab call “Eco-boulevards” connect the eight districts – the process is visualised in this video.

    UrbanLab says their vision combines a dense metropolis with a nature setting: “As a functional center, Yangming Archipelago will serve as an urban model, we expect it to lead the way to a new way of thinking about the city of the future.”

    The two-mile Pilsen Sustainable Street, commissioned by the Chicago Department of Transportation to improve the urban ecosystemPermeable pavements: Chicago’s ‘green alleys’

     

    The bioswale, an environmentally-friendly form of drainage through landscape, at the Pilsen Sustainable Street on Cermak Rd.
    Bioswale along cermak road
    • Rainwater travels through the self-cleaning, pollution-reducing sidewalk before going on to feed surrounding plants…

    …In New Jersey and New York…in response to Sandy, ZUS partnered with MIT’s Center for Advanced Urbanism and De Urbanisten to devise New Meadowlands: a masterplan for combining flood resilience with recreational amenities through marshes and a system of parallel raised banks called berms.

    Between the outer berm and the sea, the restored wetlands would soak up seawater and slow down tidal waves, preventing them from hitting the dikes at high speed. The stretch of berms would serve as a wildlife refuge, filling up with rainwater during periods of heavy rain before draining out. And on the insider of the inner berm, ditches and ponds would retain rainwater, preventing it from causing sewers to overflow….

    A terrace in Little Ferry, one of the first sites for the pilot project of New MeadowlandsBerms with benefits

     

    Floating pods – and beyond…

    Waterstudio’s Floating City Apps in a slum
  4. Climate solution in soil? Soil holds potential to slow global warming, researchers find

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    • Stanford scientists call for a renewed push to gather significantly more data on carbon in the soil and learn more about the role it plays in sequestering carbon
    • They call for an open, shared network for use by farmers, ranchers and other land managers as well as policymakers and organizations that need good data to inform land investments and conservation.
    • Improving how the land is managed could increase soil’s carbon storage enough to offset future carbon emissions from thawing permafrost with possible approaches including reduced tillage, year-round livestock forage, and compost application…planting more perennial crops, instead of annuals, could store more carbon and to reduce erosion by allowing roots to reach deeper into the ground.

    October 5, 2017 Stanford University read full ScienceDaily article here

    If you want to do something about global warming, look under your feet. Managed well, soil’s ability to trap carbon dioxide is potentially much greater than previously estimated, according to Stanford researchers who claim the resource could “significantly” offset increasing global emissions. They call for a reversal of federal cutbacks to related research programs to learn more about this valuable resource.

    The work, published in two overlapping studies Oct. 5 in Annual Review of Ecology, Evolution and Systematics and Global Change Biology, emphasizes the need for more research into how soil — if managed well — could mitigate a rapidly changing climate.

    Organic matter in soil, such as decomposing plant and animal residues, stores more carbon than do plants and the atmosphere combined. Unfortunately, the carbon in soil has been widely lost or degraded through land use changes and unsustainable forest and agricultural practices, fires, nitrogen deposition and other human activities. The greatest near-term threat comes from thawing permafrost in Earth’s northern reaches, which could release massive amounts of carbon into the atmosphere.

    Improving how the land is managed could increase soil’s carbon storage enough to offset future carbon emissions from thawing permafrost, the researchers find. Among the possible approaches: reduced tillage, year-round livestock forage and compost application. Planting more perennial crops, instead of annuals, could store more carbon and to reduce erosion by allowing roots to reach deeper into the ground….

    ….”Dirt is not exciting to most people,” said earth system science professor Rob Jackson, lead author of the Annual Review of Ecology, Evolution and Systematics article and coauthor of the Global Change Biology paper. “But it is a no-risk climate solution with big cobenefits. Fostering soil health protects food security and builds resilience to droughts, floods and urbanization.”

    ….Jackson, Harden and their colleagues call for a renewed push to gather significantly more data on carbon in the soil and learn more about the role it plays in sequestering carbon. They envision an open, shared network for use by farmers, ranchers and other land managers as well as policymakers and organizations that need good data to inform land investments and conservation.

    If we lose momentum on carbon research, it will stifle our momentum for solving both climate and land sustainability problems,” Harden said.

    Robert B. Jackson, Kate Lajtha, Susan E. Crow, Gustaf Hugelius, Marc G. Kramer, Gervasio Piñeiro. The Ecology of Soil Carbon: Pools, Vulnerabilities, and Biotic and Abiotic Controls. Annual Review of Ecology, Evolution, and Systematics, 2014; 48 (1) DOI: 10.1146/annurev-ecolsys-112414-054234

  5. Finally, a focus on saving the great forests of the Sierra. But is it too late? SacBee Editorial

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    • “There is an urgent need to reform policy and management to ensure that Californians continue to benefit from these forests for generations to come,” a new Public Policy Institute of California report says
    • Reducing forest density could have the side benefit of increasing run-off by as much as 9 percent, filling streams and rivers for the good of fisheries and for residential, agriculture and industrial use, the PPIC report says.

    Sacramento Bee Editorial  September 21, 2017 read full SacBee editorial here

    We Californians take for granted the great forests of the Sierra Nevada. It is where we ski and hike, and breathe fresh air, and it’s the primary source of our water.

    It’s all at risk. Drought and bark beetle infestation are the proximate cause of death of more than 100 million trees in California since 2010. But the forests were weakened by climate change, combined with mismanagement that includes well-intentioned wildfire prevention efforts and logging in past decades of old-growth trees, which are most resistant to fire and disease.

    [Governor] Brown and the Legislature approved another $225 million in cap-and-trade revenue, reserved for the fight against climate change, for forests. That underscored one of California’s inconvenient truths. Like refineries, diesel engines and cars powered by internal combustion, burning and decaying forests spew greenhouse gases.

    In April, the Governor’s Tree Mortality Task Force reported that the 2013 Rim Fire at Yosemite emitted 12.06 million tons of carbon dioxide, three times more than all the greenhouse gas reductions achieved that year in all other sectors in California. Worse, the detritus decomposing in the burn area will unleash four times that amount of greenhouse gas in coming decades.

    In much of the 15 million acres of mountains from Kern to Siskiyou counties, forests are choking with 400 sickly trees per acre, four times the number in healthy forests. Tools to heal the forests are at hand, but forest management is fraught.

    …Some environmentalists oppose logging, while some conservative politicians advocate unraveling environmental restrictions to allow for far more logging. Neither extreme is helpful. Flexibility is needed. The Clean Air Act could, for example, allow for the use of prescribed fires.

    …Reducing forest density could have the side benefit of increasing run-off by as much as 9 percent, filling streams and rivers for the good of fisheries and for residential, agriculture and industrial use, the PPIC report says.

    The report says the cost of wise forest management might not be astronomical. In time, it might pay for itself, assuming mills are retooled or built to accommodate smaller and mid-size timber. Such mills could provide jobs in parts of the state where unemployment is chronically high.

    …Our re-engineered state of 40 million people faces many problems. The water delivery system is oversubscribed and antiquated. Billions of dollars should be spent to reinforce California against floods.

    But there is cause for optimism. Laird last month announced the Tahoe-Central Sierra Initiative with other top officials, and some significant environmental groups are joining longtime advocates to focus on Sierra restoration. There is some support in Congress for wiser forest management.

    And now comes an infusion of state money, not to be taken for granted, and none too soon.

  6. Maximizing successful forest restoration in tropical dry forests

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    • tests maximizing success of tree replanting efforts in degraded soils in tropics
    • tree species that were drought tolerant did better
    • soil amendments only helped to get seedlings off to good start

    September 21, 2017 University of Minnesota read full ScienceDaily article here

    A new study has uncovered some valuable information on ways to maximize the success of replanting efforts [in tropical dry forests], bringing new hope for restoring these threatened ecosystems.

    …Over the past century most of these forests, which help keep water clean and provide valuable habitat for wildlife, were replaced by farms and cattle pastures. Now, as conservationists work to replant deforested areas, they’re finding that the already challenging, high-clay soils underlying them have been degraded to an extent that makes it hard for tree seedlings to sink their roots.

    …To find out what works best for reestablishing tropical dry forests, the researchers planted seedlings of 32 native tree species in degraded soil or degraded soil amended with sand, rice hulls, rice hull ash or hydrogel (an artificial water-holding material). After two years, they found that tree species known for traits that make them drought tolerant, such as enhanced ability to use water and capture sunlight, survived better than other species. Some of the soil amendments helped get seedlings off to a good start, but by the end of the experiment there was no difference in survival with respect to soil condition

    Leland K. Werden, Pedro Alvarado J., Sebastian Zarges, Erick Calderón M., Erik M. Schilling, Milena Gutiérrez L., Jennifer S. Powers. Using soil amendments and plant functional traits to select native tropical dry forest species for the restoration of degraded Vertisols. Journal of Applied Ecology, 2017; DOI: 10.1111/1365-2664.12998

  7. A better farm future starts with the soil; Opinion on the next Farm Bill

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    • With extreme weather events on the rise and farmers and foresters feeling the effects of a changing climate, however, soil health is now at the forefront of our national conversation.
    • Within the next year, the new 5 year Farm Bill will be reauthorized with implications for every aspect of food and agriculture in the US
    • the next farm bill should ensure an ongoing and growing focus on improving soil health and should make sure that USDA has the authority and funding it needs to measure and report on program outcomes…

    Within the next year Congress will reauthorize the massive amalgamation of legislation we commonly refer to as “the farm bill.” The farm bill, which is reauthorized every five years, has major implications for every part of our food and farm system and covers issues including but certainly not limited to: conservation, nutrition, local food, credit and finance, research and commodity subsidies.

    Although healthy soil is one of the essential building blocks of agriculture, historically the issue has not been a major focus of the farm bill – as some farmers would say, soil has been treated like dirt. With extreme weather events on the rise and farmers and foresters feeling the effects of a changing climate, however, soil health is now at the forefront of our national conversation.

    ….As our most significant package of food and farm legislation approaches expiration on September 30, 2018, many are asking: How can the farm bill support resilient farms, address natural resource concerns and increase productivity? A key part of the answer: promote soil health.….The next farm bill should enhance the long-term funding base for both working lands programs and ensure an ongoing and growing focus on improving soil health. In addition, the farm bill should make sure that USDA has the authority and funding it needs to measure and report on program outcomes….

    ….The Sustainable Agriculture Research and Education (SARE) program is one of the only USDA research programs with a clear and consistent focus on farmer-driven research. SARE is the leader in cutting-edge on-farm research to develop and test soil enhancement methods, such as regionally specific cover cropping or grazing management systems. The next farm bill should reauthorize and secure direct farm bill funding for SARE to ensure the program’s continued success.

    ….The farm bill must also underscore the connection between healthy soils and reduced risks for farmers, and ensure that federal crop insurance programs reward producers for advanced conservation activities and provide the appropriate incentives for those who are not currently engaged.

    Collectively, reforms to conservation, research and the farm safety net present an enormous opportunity to improve the health of our soils. …

    Alyssa Charney is a policy specialist at the National Sustainable Agriculture Coalition, and staffs the Coalition’s Conservation, Energy, and Environment Committee.

  8. Quantifying soil carbon measurement for agricultural soils management: 11 white papers

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    • Regardless of what approach is pursued, reliable and cost effective quantification methods are critical to designing and implementing improved management of soil organic matter including soil organic carbon, and C sequestration policies in the land use sector.
    Together the group, including Point Blue, produced a set of 11 white papers related to soil organic carbon quantification– see here and below.

    Quantifying soil carbon measurement for agricultural soils management: A consensus view from science

    Building a 21st-century soil information platform for US and world soils

    Soil Carbon Accounting – the Australian example

    Integrating soil carbon stocks across point to continental scales

    How do we get the most out of soil data? The opportunities and challenges of developing open soil data

    Measurement of Soil Carbon Stocks

    Meeting local/state/national/international climate change mitigation goals

    Case Study of Soil C Quantification: Alberta GHG Offset System

    EPIC model based search of agronomic strategies for increasing SOC

    Gridded agroecosystem and SOC modeling with EPIC model

    Land Management

    • There is heightened interest in increasing soil organic carbon (SOC) stocks to improve
    performance of working soils especially under drought or other stressors, to increase
    agricultural resilience, fertility and reduce greenhouse gas emissions from agriculture.
    • There are many improved management practices that can be and are currently being
    applied to cropland and grazing lands to increase SOC.
    • Farmers and ranchers are decisionmakers who operate in larger contexts that often
    determine or at least bound their agricultural and financial decisions (e.g., crop insurance, input subsidies, etc.). Any effort to value improvements in the performance of agricultural soils through enhanced levels of SOC will require feasible, credible and
    creditable assessment of SOC stocks, which are governed by dynamic and complex soil
    processes and properties.
    • This paper provides expert consensus evaluation of currently accepted methods of
    quantifying SOC that could provide the basis for a modern soil information system.
  9. Los Angeles is Painting its Streets with Light Gray ‘CoolSeal’ to Combat Climate Change; 6.6C (12F) drop in temperature in test areas

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    • Los Angeles is coating its streets with a special paint that will reduce the temperature of the city. It’s the latest step the city has taken to combat the effects of climate change alongside the state’s plans.
    • Test areas resulted in a 6.6 degrees Celsius (12 degrees Fahrenheit) drop in temperature

    September 2017 read full Futurism article here

    ….Black is a color that’s prone to absorbing heat from the sun, so black asphalt that covers a city like L.A. is sure to increase the city’s overall temperature, as proven by the record-breaking heat California has had to deal with this early September.

    Los Angeles is now coating its streets with a new gray paint called CoolSeal that will, as its name indicates, keep pavements cooler. California-based company GuardTop produces the paint, which the city tested in certain areas back in August, resulting in a 6.6 degrees Celsius (12 degrees Fahrenheit) drop in temperature….

    …Mayor Garcetti has pledged to reduce the city’s average temperature by 3 degrees Fahrenheit over the next 20 years, and he seems to be on track to do just that.

    CoolSeal being applied to Canoga Park in Los Angeles. Image Credit: GuardTop
    CoolSeal being applied to Canoga Park in Los Angeles. Image Credit: GuardTop
  10. Expect the Unexpected: SF Baylands and Climate Change – Point Blue post for Resilient by Design

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    Expecting the unexpected (originally posted for the Bay Area: Resilient By Design)

    2015-03-04 RMApano.jpgPoint Blue photos

    Trying to predict the future of our baylands could seem foolhardy given uncertainty in climate change, ecological “tipping points,” and how people prepare for these changes. Despite this, the region’s shoreline will be transformed in response to climate change and a growing human population. As we plan for the future, we must consider how to manage this transformation for people and wildlife, minimizing negative impacts and maximizing benefits.

    Securing nature’s benefits for people and wildlife

    Bay Area residents deeply value the baylands for providing healthy bird and fish habitat, improved water quality, reduced flooding, and world-class recreational opportunities. Our community’s commitment has been demonstrated by the more than  $500 million invested in wetland conservation and restoration since 1985 (as tracked by the SF Bay Joint Venture). This dedication was on full display when a supermajority of voters recently opted to tax themselves for more Baylands restoration in the face of accelerating climate change.

    PIX-CR-BN 175.jpg

    Looking forward, we need to ensure that:

    • our investments in bayland conservation are resilient to rising seas and increasingly intense storm events;
    • human assets such as roads, buildings and bridges, are protected, or appropriately relocated or redesigned;
    • underserved communities are actively engaged; and,
    • these vital adaptation endeavors entail the least cost.

    Prepare for extremes for greatest resilience

    We must also recognize that ecological change will be continuous, with sudden spurts of significant transformation.  Studies of past geologic eras, for example, show that ecosystems shifted dramatically in relatively short periods of time.  Today, we are already experiencing ecosystem transformations on a human time scale in Alaska and other parts of Earth’s polar regions where temperatures have warmed twice as fast as in the Bay Area.

    In addition, rising seas, storm events (e.g., “Superstorm” Harvey), drought and other climate change impacts continue to exceed what the science projected just a few years ago.

    Thus, the most resilient adaptation solutions will be those that are flexible and sensitive to a range of future scenarios, including extreme events at the highest end of what we know to be plausible today.

    The US Navy, for example, is now investing in strategies to address the more extreme scenarios.  According to a Harvard Business Review assessment, the Navy is raising coastal infrastructure and “improving its ability to recover rapidly when damage occurs.”  They are requiring “planners to provide additional justification when a new building is to be situated within two meters [6.6 feet] of sea-level-rise forecasts.” And, “buildings that pass this new hurdle must incorporate flood barriers and backup systems to withstand rising sea levels and storm surges.” While this “bets” approach may cost more initially, it will be essential to avoiding catastrophic outcomes from extreme and difficult to predict events.

    Highway 37: a multi-benefit, long-term approach

    “the most resilient adaptation solutions will be those that are flexible and sensitive to a range of future scenarios”

    Future planning for the Bay Area would benefit from applying the Navy’s approach.  For example, a recent UC Davis analysis of adaptation alternatives for the Highway 37 corridor, stretching from Novato to Vallejo, found that a levee embankment (making the road higher and wider to prevent flooding) would cost less than one third of a raised causeway. Given the challenges with funding transportation infrastructure improvements, it is understandable that planners may desire this alternative.

    However, the embankment would have the greatest negative ecological impacts of any of the alternatives considered.  It might constrain other future restoration alternatives in San Pablo Baylands, and will not be resilient to the high end scenarios of sea level rise and storm surge events forecasted by scientists today.  Caltrans directed UC Davis to only evaluate the costs of construction needed to prevent overtopping from three feet of sea level rise (plus a 100-year storm surge and three feet of wave run-up). This is now considered low based on the most recent science report from the state and other new studies.

    Based on these higher sea level rise projections, it is likely that the costs for the levee embankment alternative could increase substantially while the cost of the raised causeway alternatives could remain close to the same. The raised causeway options – or a bridge that would avoid the baylands entirely- would also re-establish hydrological connectivity between the baylands north of Highway 37 and the bay, reintroducing physical processes that facilitate natural adaptation to sea level rise and provide other benefits to people and wildlife.

    We urge planners, policy makers and designers, as they help the Bay Area become more resilient and responsive to continuous climate change, increasingly extreme events and unexpected transformations, to embrace Oscar Wilde’s insightful words, “To expect the unexpected shows a thoroughly modern intellect!”