Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Archive: Oct 2017

  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. Diversity of large animals plays an important role in carbon cycle

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    • We have to maintain the diversity and abundance of animals, especially mammals, in order to ensure a well-functioning carbon cycle and the retention of carbon in soils
    • To increase carbon sequestration, we have to preserve not only high numbers of animals but also many different species

    October 10, 2017 Stanford University read full ScienceDaily article here

    With abundant data on plants, large animals and their activity, and carbon soil levels in the Amazon, research suggests that large animal diversity influences carbon stocks and contributes to climate change mitigation….

    …”It’s not enough to worry about the trees in the world holding carbon. That’s really important but it’s not the whole story,” said Fragoso. “We also have to worry about maintaining the diversity and abundance of animals, especially mammals at this point, in order to ensure a well-functioning carbon cycle and the retention of carbon in soils.”

    Although scientists have long understood that animals — through ingestion, digestion, breathing and decomposition — are part of the carbon cycle, the work, published Oct. 9 in Nature Ecology and Evolution is the first to suggest the importance of animal biodiversity rather than just animal numbers in the carbon cycle.

    If we want to increase carbon sequestration, we have to preserve not only high numbers of animals but also many different species, the authors said.

    …The researchers found that soil had the highest carbon concentrations where they saw the most vertebrate species. When they looked for a mechanism that could explain this relationship, it turned out that the areas with highest animal diversity had the highest frequency of feeding interactions, such as animals preying on other animals or eating fruit, which results in organic material on and in the ground. The researchers suggest that these meal remnants bump up diversity and abundance of soil microbes, which convert the remains into stored carbon

    Mar Sobral, Kirsten M. Silvius, Han Overman, Luiz F. B. Oliveira, Ted K. Rabb, José M. V. Fragoso. Mammal diversity influences the carbon cycle through trophic interactions in the Amazon. Nature Ecology & Evolution, 2017; DOI: 10.1038/s41559-017-0334-0

  3. Herbivores help protect ecosystems from climate change

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    • In the summer, when temperatures were at their warmest in the intertidal zone, biological communities could fare well even if they were heated, but only if limpets were present

    October 11, 2017 University of British Columbia read full ScienceDaily article here

    Plant-eating critters are the key ingredient to helping ecosystems survive global warming, finds new research that offers some hope for a defense strategy against climate change.

    The herbivores created space for other plants and animals to move in and we saw much more diversity and variety in these ecosystems,” said Rebecca Kordas, the lead author of the study who completed this research as a PhD student in zoology at UBC. “We want variety because we found it helps protect the ecosystem when you add a stressor like heat.”

    …The researchers found that in the summer, when temperatures were at their warmest, communities could fare well even if they were heated, but only if limpets were present. “When limpets were part of the community, the effects of warming were less harsh,” she said….

    …The researchers were studying life in the intertidal zone, the area of the shore between the low tide and high tide. This area is home to a community of starfish, anemones, mussels, barnacles and seaweed. As the tide moves in and out, the plants and animals must cope with huge variation in temperature every day, sometimes as much as 20 to 25 degrees Celsius.

    These creatures are already living at their physiological limits, so a two-degree change –– a conservative prediction of the warming expected over the next 80 years or so — can make a big difference,” said Kordas. “When heat waves come through B.C. and the Pacific Northwest, we see mass mortality of numerous intertidal species.”…

    Rebecca L. Kordas, Ian Donohue, Christopher D. G. Harley. Herbivory enables marine communities to resist warming. Science Advances, 2017; 3 (10): e1701349 DOI: 10.1126/sciadv.1701349

  4. The world’s first “negative emissions” plant has begun operation—turning carbon dioxide into stone

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    Akshat Rathi October 12, 2017 read full Quartz article here

    …We produce 40 trillion kg of carbon dioxide each year, and we’re on track to cross a crucial emissions threshold that will cause global temperature rise to pass the dangerous 2°C limit set by the Paris climate agreement.
    …On Oct. 11, at a geothermal power plant in Iceland, the startup inaugurated the first system that does direct air capture and verifiably achieves negative carbon emissions. Although it’s still at pilot scale—capturing only 50 metric tons CO2 from the air each year, about the same emitted by a single US household—it’s the first system to convert the emissions into stone, thus ensuring they don’t escape back into the atmosphere for the next millions of years.
    …Climeworks and Global Thermostat have piloted systems in which they coat plastics and ceramics, respectively, with an amine, a type of chemical that can absorb CO2. Carbon Engineering uses a liquid system, with calcium oxide and water. …
    …Each of the startups has built a functional pilot plant to prove their technology, with the ability to capture hundreds of kg of CO2. And all boast that their tech is modular, meaning they can build a direct air capture plant as small or large as somebody is ready to pay for. Even at $50 per metric ton of capturing emissions, if we have to capture as much as 10 billion metric tons by 2050, we are looking at spending $500 billion each year capturing carbon dioxide from the air. It seems outrageous, but it may not be if climate change’s other damages are put in perspective—and that’s what these startups are betting on….
  5. Northern California firestorm ‘literally exploded’; 2015 study found warming climate to make “Diablo” offshore winds more frequent and stronger, fueling more destructive fires

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    • years of drought followed by record-breaking rainfall increased fuel load [after a century of fire-suppression combined with inappropriate siting of houses and other built infrastructure]
    • 2015 study found that a warming climate will likely make these “Diablo” offshore winds both more frequent and stronger, fueling potentially destructive fires

    Updated Oct 11 2017  Read full ClimateProgress article here

    …The fires ignited late Sunday night and into Monday morning and have since spread over 50,000 acres across Napa and Sonoma counties, destroying at least 3,500 structures and sending at least 100 to the hospital with injuries ranging from burns to smoke inhalation…

    …Fast-moving winds and low humidity aren’t rare in California, and neither are October wildfires, but it’s likely climate change made these fires even more destructive. After years of historic, prolonged drought, which studies have linked to climate change, California experienced record-setting rains that fueled the growth of grasses and underbrush — young vegetation that dries easily during the summer and is especially susceptible to ignition. Because warmer atmospheric temperatures can hold more water, experts have suggested that the cycle of drought followed by intense precipitation could be linked to climate change.

    Even the state’s characteristic winds — known in the northern part of the state as Diablo Winds and in the southern part of the state as Santa Ana winds — could be getting worse because of climate change. The Santa Ana and Diablo winds occur when high inland pressure pushes air down the sides of mountains (Mt. Diablo in northern California and Mt. Ana in southern California), whipping wind through the canyons and hillsides outside major population centers like Los Angeles and San Francisco. According to a 2015 study lead by researchers at University of California, Los Angles, UC Davis, UC Irvine, and the U.S. Forest Service, a warming climate will likely make these winds both more frequent and stronger, fueling potentially destructive fires….

    ….The National Wildfire Coordinating Group currently lists 179 active wildfire situations throughout much of the Western United States, from Colorado to Washington. The largest active fire in the United States is the Chetco Bar Fire in southern Oregon, which has burned over 191,121 acres and is 97 percent contained. As of October 6, wildfires have burned 8,469,590 acres across the United States — the third largest total acreage burned in the last 10 fire seasons….

  6. Slightly warmer temperatures and moderate CO2 [275 ppm] ~120,000 years ago led to superstorms and abrupt multi-meter sea-level rise

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    • geologic findings from the western Atlantic Ocean indicate ominous prospects for a warming Earth
    October 12, 2017  Elsevier read full ScienceDaily article here
    While strong seasonal hurricanes have devastated many of the Caribbean and Bahamian islands this year, geologic studies on several of these islands illustrate that more extreme conditions existed in the past..[per a] new analysis [showing] that the limestone islands of the Bahamas and Bermuda experienced climate changes … even more extreme.
    …[The study] demonstrates that during a global climate transition in the late last interglacial (approximately 120,000 years ago)… abrupt multi-meter sea-level changes occurred. Concurrently, coastlines of the Bahamas and Bermuda were impacted by massive storms generated in the North Atlantic Ocean…
    ….During the last interglacial, sea levels were about 3-9 meters higher than they are now. The geologic evidence indicates that the higher sea-levels were accompanied by intense “superstorms,” which deposited giant wave-transported boulders at the top of cliffed coastlines, formed chevron-shaped, storm beach ridges in lowland areas, and left wave runup deposits on older dunes more than 30 meters above sea level. These events occurred at a time of only slightly warmer global climate and CO2 (about 275 ppm) was much lower than today….
    …The authors emphasize “the LIG record reveals that strong climate forcing is not required to yield major impacts on the ocean and ice caps.” In our industrial world, rapidly increasing atmospheric CO2 has surpassed 400 ppm, levels not achieved since the Pliocene era about 3 million years ago, while global temperature has increased nearly 1 °C since the 1870s….

    P.J. Hearty, B.R. Tormey. Sea-level change and superstorms; geologic evidence from the last interglacial (MIS 5e) in the Bahamas and Bermuda offers ominous prospects for a warming Earth. Marine Geology, 2017; 390: 347 DOI: 10.1016/j.margeo.2017.05.009

  7. Even modest oil exposure can harm coastal and marine birds

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    • “Even birds with relatively limited exposure to oil from the Deepwater Horizon spill sustained damage to circulating red blood cells and had evidence of anemia, which can adversely affect reproduction and reduce survival.”

    October 12, 2017 Wiley read full ScienceDaily article here

    Many birds and other wildlife die following an oil spill, but there are also other potential long-terms effects of oil exposure on animals. study that examined blood samples from birds present in the Gulf of Mexico in 2010 and 2011 following the Deepwater Horizon oil spill, even birds with small amounts of oil present on their feathers experienced problems related to their red blood cells.

    The findings show that even modest oil exposure can cause problems for individual birds and bird populations.

    Jesse A. Fallon, Eric P. Smith, Nina Schoch, James D. Paruk, Evan A. Adams, David C. Evers, Patrick G.R. Jodice, Christopher Perkins, Shiloh Schulte, William A. Hopkins. Hematological indices of injury to lightly oiled birds from the deepwater horizon oil spill. Environmental Toxicology and Chemistry, 2017; DOI: 10.1002/etc.3983

  8. Better managing plastic waste in 10 rivers could stem ~90% of plastics in the ocean

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    • Scientists have found that 10 rivers around the world where plastic waste is mismanaged contribute 88-95% of global load of plastics in the ocean.
    • Halving plastic pollution in these 10 waterways — eight of which are in Asia — could potentially reduce the total contribution by all rivers by 45 percent.

    October 11, 2017 American Chemical Society see full ScienceDaily article here

    Massive amounts of plastic bits that are dangerous to aquatic life are washing into the oceans and into even the most pristine waters. But how it all gets there from inland cities has not been fully understood. Now scientists have found that 10 rivers around the world where plastic waste is mismanaged contribute to most of the oceans’ total loads that come from rivers.

    ..the amount of plastic in rivers was related to the mismanagement of plastic waste in their watersheds. Additionally, the top 10 rivers carrying the highest amounts accounted for 88 to 95 percent of the total global load of plastics in the oceans, according to the researcher’s calculations.

    The researchers say halving plastic pollution in these 10 waterways — eight of which are in Asia — could potentially reduce the total contribution by all rivers by 45 percent.

    Christian Schmidt, Tobias Krauth, Stephan Wagner. Export of Plastic Debris by Rivers into the Sea. Environmental Science & Technology, 2017; DOI: 10.1021/acs.est.7b02368

  9. Electric Vehicles Expected to Push Oil Demand Down

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    • With China now planning to phase out gas-powered cars, automakers are talking about an all-electric future. It could mean a big drop in emissions.
  10. Droughts and wildfires in southwest: Global warming is drying up the North American monsoon

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    • North American monsoon, the summer rains that sweep across the southweset US and northwestern Mexico, is not simply delayed; the Southwest faces a dramatic reduction in rainfall

    October 9, 2017 Princeton University read full ScienceDaily article here

    Previous researchers had concluded that global warming was simply delaying the North American monsoon, which brings summer rains to the southwestern US and northwestern Mexico. But a new, high-resolution climate model that corrects for persistent sea surface temperature (SST) biases now accurately reflects current rainfall conditions and demonstrates that the monsoon is not simply delayed, but that the region’s total rainfall is facing a dramatic reduction

    ..most of those droughts are attributed to the change in winter storms, said Pascale. “The storm track is projected to shift northward, so these regions might get less rain in winter, but it was very uncertain what happens to the monsoon, which is the other contributor to the rains of the region. We didn’t know, and it’s crucial to know,” he said…[they quantified] the monsoon response to the doubling of atmospheric carbon dioxide, increased temperatures and other individual changes…

    Salvatore Pascale, William R. Boos, Simona Bordoni, Thomas L. Delworth, Sarah B. Kapnick, Hiroyuki Murakami, Gabriel A. Vecchi, Wei Zhang. Weakening of the North American monsoon with global warming. Nature Climate Change, 2017; DOI: 10.1038/nclimate3412