70 research outputs found

    Global Carbon Budget 2021

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    COSORE: A community database for continuous soil respiration and other soil‐atmosphere greenhouse gas flux data

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    Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soil‐to‐atmosphere CO2 flux, commonly though imprecisely termed soil respiration (RS), is one of the largest carbon fluxes in the Earth system. An increasing number of high‐frequency RS measurements (typically, from an automated system with hourly sampling) have been made over the last two decades; an increasing number of methane measurements are being made with such systems as well. Such high frequency data are an invaluable resource for understanding GHG fluxes, but lack a central database or repository. Here we describe the lightweight, open‐source COSORE (COntinuous SOil REspiration) database and software, that focuses on automated, continuous and long‐term GHG flux datasets, and is intended to serve as a community resource for earth sciences, climate change syntheses and model evaluation. Contributed datasets are mapped to a single, consistent standard, with metadata on contributors, geographic location, measurement conditions and ancillary data. The design emphasizes the importance of reproducibility, scientific transparency and open access to data. While being oriented towards continuously measured RS, the database design accommodates other soil‐atmosphere measurements (e.g. ecosystem respiration, chamber‐measured net ecosystem exchange, methane fluxes) as well as experimental treatments (heterotrophic only, etc.). We give brief examples of the types of analyses possible using this new community resource and describe its accompanying R software package

    Global Carbon Budget 2022

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    Accurate assessment of anthropogenic carbon dioxide (CO2_2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2_2 emissions (EFOS_{FOS}) are based on energy statistics and cement production data, while emissions from land-use change (ELUC_{LUC}), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2_2 concentration is measured directly, and its growth rate (GATM_{ATM}) is computed from the annual changes in concentration. The ocean CO2_2 sink (SOCEAN_{OCEAN}) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2_2 sink (SLAND_{LAND}) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM_{IM}), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2021, EFOS_{FOS} increased by 5.1 % relative to 2020, with fossil emissions at 10.1 ± 0.5 GtC yr1^{−1} (9.9 ± 0.5 GtC yr1^{−1} when the cement carbonation sink is included), and ELUC_{LUC} was 1.1 ± 0.7 GtC yr1^{−1}, for a total anthropogenic CO2_2 emission (including the cement carbonation sink) of 10.9 ± 0.8 GtC yr1^{−1} (40.0 ± 2.9 GtCO2_2). Also, for 2021, GATM_{ATM} was 5.2 ± 0.2 GtC yr1^{−1} (2.5 ± 0.1 ppm yr1^{−1}), SOCEAN_{OCEAN} was 2.9  ± 0.4 GtC yr1^{−1}, and SLAND_{LAND} was 3.5 ± 0.9 GtC yr1^{−1}, with a BIM_{IM} of −0.6 GtC yr1^{−1} (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2_2 concentration averaged over 2021 reached 414.71 ± 0.1 ppm. Preliminary data for 2022 suggest an increase in EFOS_{FOS} relative to 2021 of +1.0 % (0.1 % to 1.9 %) globally and atmospheric CO2_2 concentration reaching 417.2 ppm, more than 50 % above pre-industrial levels (around 278 ppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2021, but discrepancies of up to 1 GtC yr1^{−1} persist for the representation of annual to semi-decadal variability in CO2_2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2_2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set. The data presented in this work are available at https://doi.org/10.18160/GCP-2022 (Friedlingstein et al., 2022b)

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    A nitrogen based model for the cycling of carbon dioxide in the subarctic Pacific Ocean

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    This model explores the integration of a physical mixing model with an ecological model for the studies of the CO2 problem in the ocean. The model is specifically for the regional CO2 cycling at Ocean Station P (OSP, 50° N, 145°W) and is composed of a physical submodel for physical processes and a biological submodel for biological processes. By dividing the water column into a number of layers, I have defined physical processes as those affecting material flux between boxes and biological processes as affecting material flow within a box. The direct target of the model is the cycling of nitrogen from which the cycling of CO2 can be derived. The physical submodel basically deals with the turbulent mixing, particulate sinking, and zooplankton migration at OSP. Zooplankton migration is included in the physical submodel because it acts between boxes rather than within boxes. Considering the theoretical simplicity, I used the Mellor and Yamada's level II model for the turbulent mixing. Although available boundary conditions are not sufficient to give a satisfactory continuous time modelling of the mixing, the model did provide a practical formula for estimating the seasonal turbulent mixing coefficient from the temperature profile, with assumptions of a steady-state temperature and constant wind induced current shear. The advantage of this method is that the mixing coefficient in the mixed-layer, which is commonly treated as infinite, can be actually calculated. The mixing coefficient in and below the mixed-layer of OSP obtained by my method is well within the range of those obtained by other methods (Anderson et al., 1977; Denman and Gargett, 1983). My estimation gives a approximate number of 2.5x10-3m2 s-1 for the mixed-layer and 1.0-4.0x10-4m2 s1 for layers below. Using mixing coefficients in an ecological model is one of the advances that this research contributes to the modelling of the biological pump in CO2 cycling. The biological submodel is basically derived from the model of Fasham et al.(1990) and contains the basic components of ammonium, nitrate, phytoplankton, zooplankton, bacterial, DON, PON, and a higher trophic zooplankton. The main difference of this biological model from others is that biological components are allowed to move in the whole water column rather than being confined in one box. The integration of the biological submodel with the physical submodel eliminate the boundary limitation from a one-box model which sets the boundary at the bottom of the mixed-layer. In general, the model reproduces almost all basic ecological characteristics observed at OSP, including (1) Seasonal variation of phytoplankton and zooplankton biomass, (2) seasonal primary production and PON flux, and (3) seasonal ammonium and nitrate concentration and the f-ratio. The model confirmed that the phytoplankton growth at OSP is controlled by zooplankton grazing. Reducing zooplankton grazing would result in high phytoplankton stocks in the spring, as is observed in other regions (Raymont, 1980). However, other unknown factors (e.g. Fe, Martin et al. (1989)) may affect the growth of phytoplankton, especially their preference for ammonium (Price et al., 1991). The model indicates that the food web at OSP has a high efficiency in converting nitrogen from phytoplankton to zooplankton. This factor, combined with the high utilization ratio of ammonium by phytoplankton and upwelling rate, may bean explanation why a high nitrate concentration can remain in such a highly productive open sea. By comparing the simulated results with observations, I conclude that an annualCO2 flux of 100 g m-2 y' would be a reasonable estimate for OSP. But the net uptake of CO2 from the atmosphere can not be estimated accurately by a one-dimensional model. According to Miller et al. (1991), new nutrient input to the euphotic zone of OSP is mainly determined by the upwelling convection. However, the model indicates that the turbulent mixing may play an equal role in this input. The results of the model support the conclusion of Kirchman and Keil (1990) that bacterial growth at OSP is limited by organic carbon. The results also point out that the bacterial production maybe as high as the primary production and therefore sustain about half of the food requirements of zooplankton.Science, Faculty ofEarth, Ocean and Atmospheric Sciences, Department ofGraduat

    Global surface ocean CO2 in 1990-2015 obtained by machine learning models.

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    This package includes data used to train three machine learning models, modeled global surface ocean CO2 in 1990-2015, and binary model programs. Please refer to the following article for technical details (in press):<br><br>Technical note: Evaluation of three machine learning models for surface ocean CO2 mapping. doi:10.5194/os-13-1-2017<br><br
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