Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Tag Archive: carbon

  1. White House quietly cancels NASA research verifying greenhouse gas cuts

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    • “If you cannot measure emissions reductions, you cannot be confident that countries are adhering to the agreement,” she says. Canceling the CMS “is a grave mistake

    By Paul Voosen May. 9, 2018  Read full Science Magazine article here

    You can’t manage what you don’t measure. The adage is especially relevant for climate-warming greenhouse gases, which are crucial to manage—and challenging to measure. In recent years, though, satellite and aircraft instruments have begun monitoring carbon dioxide and methane remotely, and NASA’s Carbon Monitoring System (CMS), a $10-million-a-year research line, has helped stitch together observations of sources and sinks into high-resolution models of the planet’s flows of carbon. Now, [the White House] has quietly killed the CMS, Science has learned.

    The move jeopardizes plans to verify the national emission cuts agreed to in the Paris climate accords, says Kelly Sims Gallagher, director of Tufts University’s Center for International Environment and Resource Policy in Medford, Massachusetts. “If you cannot measure emissions reductions, you cannot be confident that countries are adhering to the agreement,” she says. Canceling the CMS “is a grave mistake,” she adds….

  2. Carbon satellite to serve as an important tool for politicians and climate change experts

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    • a new French satellite can measure carbon balance far more precisely than the current method, which uses aerial photography.
    • The satellite uses low-frequency passive microwaves to measure the biomass of above ground vegetation

    08 May 2018 University of Copenhagen  Read full ScienceDaily article here

    A new satellite that measures and provides detailed carbon balance information is one of the most important new tools in carbon measurement since infrared light. The researchers expect the satellite to be a valuable tool for the UN’s work on climate change related to the Paris climate accord.

    Carbon balance is important for climate and environment because whenever carbon is converted into carbon dioxide, CO2 emissions increase. On the other hand, carbon is an essential aspect of life on Earth: a felled tree releases carbon into the atmosphere whereas a planted one takes up carbon in vegetation and soil. A lack of carbon in vegetation and soil can create a carbon imbalance and have climate-related consequences.

    University of Copenhagen researchers have tested a new French satellite that can measure carbon balance far more precisely than the current method, which uses aerial photography. The satellite uses low-frequency passive microwaves to measure the biomass of above ground vegetation. The studies have recently been published in Nature Ecology and Evolution….

    Martin Brandt, et al. Satellite passive microwaves reveal recent climate-induced carbon losses in African drylands. Nature Ecology & Evolution, 2018; 2 (5): 827 DOI: 10.1038/s41559-018-0530-6

  3. Grazing Management to Improve Soil Health- rotational grazing can improve soil health over continuous grazing strategies

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    • Proper livestock grazing – which maintains and improves soil health – results in a series of interconnected positive outcomes including:
      • Soil densities and structure that allow root and water penetration of the entire soil profile.
      • Vigorous forage plants with capacity to develop and maintain extensive rooting systems.
      • A community of palatable forage plants with high rooting mass and depth.
      • Stable, resilient increases in primary productivity both above- and below- ground.

    Ken Tate April 9 2018  Read full UC Rangelands article here

    Grazing lands occupy nearly half the Earth’s land area, provide livelihoods for millions, and mitigate climate change via massive stores of carbon. Maintaining and restoring soil health is essential to ensuring these benefits in our ever changing environment.

    Thus, there is substantial global interest in managing livestock grazing to improve soil health. Grazing is promoted by some as a panacea for sequestering carbon and mitigating climate change. In other cases, grazing is depicted as an ultimate driver of soil degradation….

    …Our findings (Byrnes et al. 2018) suggest that rotational grazing can improve soil health over continuous grazing strategies. Decisions about grazing strategy and intensity significantly influence soil health outcomes, and site-specific conditions play important roles in shaping these out­comes.

    Byrnes, R.C., D.J. Eastburn, K.W. Tate, and L.M. Roche*. 2018. A global meta-analysis of grazing impacts on soil health indicators. J. Environmental Quality. doi:10.2134/jeq2017.08.0313.

    See previous post here.

  4. Climate Change and Agriculture– Point Blue comments on the “Koronivia joint work on agriculture” (Dec 4/CP.23) submitted to the UNFCCC

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    March 30, 2018

    We at Point Blue submitted the attached recommendations last week on climate change and agriculture as an Observer to the United Nations Framework Convention on Climate Change (UNFCCC).

    See the document here:Point Blue (Observer) Submission on Issues Related to Agriculture per Korovinia* D4 CP23 UNFCCC March 30 2018 FIN

    See here for the UNFCCC Decision 4/COP23 inviting comments from parties and observers for the subsidiary science and technical bodies meetings in Bonn at the end of April 2018.

    See Presentations & Recordings from the Global Webinar  and more from my blog on the Koronivia joint work on agriculture decision from COP 23.  See also for more background: Koronivia: setting the stage for an agricultural transformation.

    See also for more information on the Koronivia joint work on agriculture: www.fao.org/climate-change/resources/learning/

    *Koronivia grass is a leafy, procumbent, creeping, stoloniferous perennial grass

  5. Vegetation controls the future of the water cycle

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    • This study highlights the key role of vegetation in controlling future terrestrial hydrologic response.
    • Carbon and water cycles are intimately coupled over land and must be studied as an interconnected system.
    • Hydrologists should collaborate with ecologists and climate scientists to better predict future water resources.
    • “Plants are at the center of the water, energy, and carbon cycles. As they take up carbon from the atmosphere to thrive, they release water that they take from the soils. Doing that, they also cool off the surface, controlling the temperature that we all feel. Now we know that mainly plants- not simply precipitation or temperature-will tell us whether we will live a drier or wetter world.”

    April 2, 2018 Columbia University School of Engineering and Applied Science Read full Science Daily Article here

    Researchers have found that vegetation plays a dominant role in Earth’s water cycle, that plants will regulate and dominate the increasing stress placed on continental water resources in the future…

    …”The biosphere physiological effects and related biosphere-atmosphere interactions are key to predicting future continental water stress as represented by evapotranspiration, long-term runoff, soil moisture, or leaf area index,” Gentine says. “In turn, vegetation water stress largely regulates land carbon uptake, further emphasizing how tightly the future carbon and water cycles are coupled so that they cannot be evaluated in isolation.”

    ….Gentine and Lemordant plan to further untangle the various physiological effects. “The vegetation response is itself indeed complex,” Gentine says, “and we want to decompose the impact of biomass growth vs. stomatal response. There are also implications for extreme heatwave events we are currently working on.”

    “This work highlights an important need to further study how plants will respond to rising atmospheric carbon dioxide,” says James Randerson, professor of earth system science, University of California, Irvine, who was not involved with the study. “Plants can have a big effect on the climate of land, and we need to better understand the ways that they will respond to carbon dioxide, warming, and other forms of global change.”

    Léo Lemordant et al. Critical impact of vegetation physiology on the continental hydrologic cycle in response to increasing CO2. PNAS, 2018 DOI: 10.1073/pnas.1720712115

  6. Climate change threatens world’s largest seagrass carbon stores

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    • Seagrass meadows are CO2 sinks, known as ‘Blue Carbon ecosystems’. They take up and store carbon dioxide in their soils and biomass through biosequestration.
    • we need to advance our understanding of how seagrass ecosystems, especially those living close to their thermal tolerance, will respond to global change threats, both direct and through interactive effects with local pressures.

    March 19, 2018 Universitat Autònoma de Barcelona  read full ScienceDaily article here

    In the summer of 2010-2011 Western Australia experienced an unprecedented marine heat wave that elevated water temperatures 2-4°C above average for more than 2 months. The heat wave resulted in defoliation of the dominant Amphibolis antarctica seagrass species across the iconic Shark Bay World Heritage Site…

    ….Over the three years following the event, the loss of seagrass released up to nine million metric tons of carbon dioxide (CO2) into the atmosphere. This amount is roughly the equivalent to the annual CO2 output of 800,000 homes, two average coal-fired power plants, or 1,600,000 cars driven for 12 months. It also potentially raised Australia’s annual estimate of national land-use change CO2 emissions by up to 21%….

    …”This is significant, as seagrass meadows are CO2 sinks, known as ‘Blue Carbon ecosystems’. They take up and store carbon dioxide in their soils and biomass through biosequestration. The carbon that is locked in the soils is potentially there for millennia if seagrass ecosystems remain intact,” explains Professor Pere Masqué, co-author of the study and researcher at ICTA-UAB and the UAB Department of Physics….

    …”We need to advance our understanding of how seagrass ecosystems, especially those living close to their thermal tolerance, will respond to global change threats, both direct and through interactive effects with local pressures….

    A. Arias-Ortiz, O. Serrano, P. Masqué, P. S. Lavery, U. Mueller, G. A. Kendrick, M. Rozaimi, A. Esteban, J. W. Fourqurean, N. Marbà, M. A. Mateo, K. Murray, M. J. Rule & C. M. Duarte. A marine heatwave drives massive losses from the world’s largest seagrass carbon stocks. Nature Climate Change, 2018 DOI: 10.1038/s41558-018-0096-y

  7. Coastal water absorbing more carbon dioxide

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    • Findings may help scientists understand how much carbon dioxide can be released while still limiting global warming

    • while the amount of carbon dioxide in the open ocean is increasing at the same rate as in the atmosphere, these same carbon dioxide concentrations are increasing slower in the coastal ocean because the coastal ocean is shallower than the open ocean and can quickly transfer sequestered carbon dioxide to the deep ocean…
    • nutrient pollution entering coastal waters from things like fertilizer on land stimulate the growth of algae within the continental shelves, which subsequently removes more carbon dioxide from the atmosphere
    • the continental shelves are becoming a crucial element in the global carbon cycle and for the climate system; scientists should take into account the contribution of continental shelves to calculate global carbon budgets

    January 31, 2018 University of Delaware read full ScienceDaily article here

    Oceanographers reveal that the water over the continental shelves is shouldering a larger than expected portion of atmospheric carbon dioxide. The findings may have important implications for scientists focused on understanding how much carbon dioxide can be released into the atmosphere while still keeping warming limited.

    As more carbon dioxide enters the atmosphere, the global ocean soaks up much of the excess, storing roughly 30 percent of the carbon dioxide emissions coming from human activities.

    In this sense, the ocean has acted as a buffer to slow down the greenhouse gas accumulation in the atmosphere and, thus, global warming. However, this process also increases the acidity of seawater and can affect the health of marine organisms and the ocean ecosystem.

    New research by University of Delaware oceanographer Wei-Jun Cai and colleagues at Université Libre de Bruxelles, Texas A&M University-Corpus Christi, University of Hawaii at Manoa and ETH Zurich, now reveals that the water over the continental shelves is shouldering a larger portion of the load, taking up more and more of this atmospheric carbon dioxide….

    Goulven G. Laruelle, Wei-Jun Cai, Xinping Hu, Nicolas Gruber, Fred T. Mackenzie, Pierre Regnier. Continental shelves as a variable but increasing global sink for atmospheric carbon dioxide. Nature Communications, 2018; 9 (1) DOI: 10.1038/s41467-017-02738-z

  8. Managing grazing lands to improve soils and promote climate change adaptation and mitigation: a global synthesis

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    • Findings reveal that a variety of management strategies have the potential to improve soil water infiltration rates, with possible benefits for soil carbon as well.
    • Researchers identified a shortage of well-replicated and detailed experiments in all grazing management categories, and call for additional research of both soil water and soil carbon properties for these critical agroecosystems

    DeLonge, M. and Basche, A., 2017. Managing grazing lands to improve soils and promote climate change adaptation and mitigation: a global synthesis. Renewable Agriculture and Food Systems, pp.1-12.

    Abstract

    The potential to improve soils to help farmers and ranchers adapt to and mitigate climate change has generated significant enthusiasm. Within this discussion, grasslands have surfaced as being particularly important, due to their geographic range, their capacity to store substantial quantities of carbon relative to cultivated croplands and their potential role in mitigating droughts and floods. However, leveraging grasslands for climate change mitigation and adaptation will require a better understanding of how farmers and ranchers who rely on them for their livelihoods can improve management and related outcomes.

    To investigate opportunities for such improvements, we conducted a meta-analysis of field experiments that investigated how soil water infiltration rates are affected by a range of management options: adding complexity to grazing patterns, reducing stocking rates or extended rest from grazing. Further, to explore the relationships between observed changes in soil water infiltration and soil carbon, we identified papers that reported data on both metrics. We found that in 81.9% of all cases, responses of infiltration rates to identified management treatments (response ratios) were above zero, with infiltration rates increasing by 59.3 ± 7.3%. Mean response ratios from unique management categories were not significantly different, although the effect of extended rest (67.9 ± 8.5%, n = 140 from 31 experiments) was slightly higher than from reducing stocking rates (42.0 ± 10.8%; n = 63 from 17 experiments) or adding complexity (34.0 ± 14.1%, n =17 from 11 experiments). We did not find a significant effect of several other variables, including treatment duration, mean annual precipitation or soil texture; however, analysis of aridity indices suggested that grazing management may have a slightly larger effect in more humid environments. Within our database, we found that 42% of complexity studies, 41% of stocking rate studies and 29% of extended rest studies also reported at least some measure of soil carbon. Within the subset of cases where both infiltration rates and carbon were reported, response ratios were largely positive for both variables (at least 64% of cases had positive mean response ratios in all management categories).

    Overall, our findings reveal that a variety of management strategies have the potential to improve soil water infiltration rates, with possible benefits for soil carbon as well. However, we identified a shortage of well-replicated and detailed experiments in all grazing management categories, and call for additional research of both soil water and soil carbon properties for these critical agroecosystems.

  9. 20 percent more trees in megacities would mean cleaner air and water, lower carbon and energy use

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    18 Jan 2018   read full ScienceDaily article here

    Planting 20 percent more trees in our megacities would double the benefits of urban forests, like pollution reduction, carbon sequestration and energy reduction. The authors of the study say city planners, residents and other stakeholders should start looking within cities for natural resources and conserve the nature in our urban areas by planting more trees….

    T. Endreny, R. Santagata, A. Perna, C. De Stefano, R.F. Rallo, S. Ulgiati. Implementing and managing urban forests: A much needed conservation strategy to increase ecosystem services and urban wellbeing. Ecological Modelling, 2017; 360: 328 DOI: 10.1016/j.ecolmodel.2017.07.016

  10. New estimate of how much humans have transformed the planet; habitat restoration of degraded lands is key to sequestering carbon and reversing climate change

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    • Current human use of land is responsible for ~halving the potential storage of carbon by that land. 
    • Through large-scale grazing and other uses of grasslands, as well as forest “management,” humans have subtracted from Earth’s potential carbon sequestration in vegetation an amount equal to deforestation.
    • Earth’s vegetation currently stores around 450 petagrams of carbon [450 billion tons (or gigatons Gt) of carbon or 1665 Gt of CO2e] and in a hypothetical without land use changes, potential vegetation would store around 916 petagrams of carbon, under current climate conditions.
    • Avoiding deforestation is necessary but not enough to reverse climate change.
    • Scenarios that limit global warming to 1.5 or 2 degrees [Celsius] require not only rapid cessation of greenhouse gas emissions but also removal of somewhere between about 100 and 300 billion tons of carbon [or 370 to 1110 billion tons (Gt) of CO2e] from the atmosphere; restoring vegetation is key contribution to controlling climate change
    by Chris Moony Dec 20 2017  see full Washington Post article

    In this age of climate change, we naturally train our attention on all the fossil fuels being combusted for human use — but scientists have long known that what’s happening is also all about the land.

    Just as buried fossil fuels are filled with carbon from ancient plant and animal life, so too are living trees and vegetation on Earth’s surface today. Razing forests or plowing grasslands puts carbon in the atmosphere just like burning fossil fuels does.

    Now, new research provides a surprisingly large estimate of just how consequential our treatment of land surfaces and vegetation has been for the planet and its atmosphere. If true, it’s a finding that could shape not only our response to climate change, but our understanding of ourselves as agents of planetary transformation….

    ….Using a series of detailed maps derived from satellite information and other types of ecological measurements, Erb and his colleagues estimated how much carbon is contained in Earth’s current vegetation. The number is massive: 450 billion tons of carbon, which, if it were to somehow arrive in the atmosphere as carbon dioxide, would amount to over a trillion tons of the gas. (The mass is greater due to the addition of oxygen molecules.)

    But the study also presented an even larger and perhaps more consequential number: 916 billion tons. That’s the amount of carbon, the research calculated, that could reside in the world’s vegetation — so not in the atmosphere — if humans somehow entirely ceased all uses of land and allowed it to return to its natural state. The inference is that current human use of land is responsible for roughly halving the potential storage of carbon by that land….

    …the impact calculation is so large because humans have done far more than just bring about deforestation, which Erb said accounts for about half of the loss of potential vegetation. … “But the other half, in most studies, is completely missing.”…

    …The study found that there are two far-less-recognized components of how humans have subtracted from Earth’s potential vegetation — and that in combination they are just as substantial as deforestation. Those are large-scale grazing and other uses of grasslands, as well as forest “management.” With the latter, many trees and other types of vegetation are subtracted from forests — often the larger and older trees due to logging — but the forests as a whole don’t disappear. They’re just highly thinned out.

    “This effect is quite massive, more massive than we expected actually,” Erb said….

    ….The research means that so-called degraded land — not fully deforested but not “natural” or whole, either — is a phenomenon to be reckoned with.

    “It suggests that the amount of carbon released to the atmosphere from land use is approximately equal to the amount still retained,” said Tom Lovejoy, an ecologist at George Mason University who was not involved in the work. “That means the restoration agenda is even more important than previously thought and highlights the enormous amount of degraded land in the world.”…

    ….“Scenarios that limit global warming to 1.5 or 2 degrees [Celsius] require not only rapid cessation of greenhouse gas emissions but also removal of somewhere between about 100 and 300 billion tons of carbon [or 370 to 1110 billion tons (Gt) of CO2e] from the atmosphere,” Phil Duffy, president of the Woods Hole Research Center, said in an email.

    This paper suggests that restoring vegetation around the world could in principle achieve that,” Duffy continued, noting that if all the potential vegetation were restored it would offset some 50 years of global carbon emissions. While “the full theoretical potential will never be realized in practice … this paper indicates that restoring vegetation could make an extremely important contribution to controlling global climate change.”

    Karl-Heinz Erb et al. Unexpectedly large impact of forest management and grazing on global vegetation biomass. Nature  Dec 2017 doi:10.1038/nature25138
     
     Abstract: Carbon stocks in vegetation have a key role in the climate system. However, the magnitude, patterns and uncertainties of carbon stocks and the effect of land use on the stocks remain poorly quantified. Here we show, using state-of-the-art datasets, that vegetation currently stores around 450 petagrams of carbon. In the hypothetical absence of land use, potential vegetation would store around 916 petagrams of
    carbon, under current climate conditions. This difference highlights the massive effect of land use on biomass stocks. Deforestation and other land-cover changes are responsible for 53–58% of the difference between current and potential biomass stocks. Land management effects (the biomass stock changes induced by land use within the same land cover) contribute 42–47%, but have been underestimated in the literature. Therefore, avoiding deforestation is necessary but not sufficient for mitigation of climate change. Our results imply that trade-offs exist between conserving carbon stocks on managed land and raising the contribution of biomass to raw material and energy supply for the mitigation of climate change. Efforts to raise biomass stocks are currently verifiable only in temperate forests, where their potential is limited. By contrast, large uncertainties hinder verification in the tropical forest, where the largest potential is located, pointing to challenges for the upcoming stocktaking exercises under the Paris agreement.