Global Carbon Budget 2021

Accurate assessment of anthropogenic carbon dioxide (CO2) 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 methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land-use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data-products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), 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 first time, an approach is shown to reconcile the difference in our ELUC estimate with the one from national greenhouse gases inventories, supporting the assessment of collective countries’ climate progress. For the year 2020, EFOS declined by 5.4 % relative to 2019, with fossil emissions at 9.5 ± 0.5 GtC yr−1 (9.3 ± 0.5 GtC yr−1 when the cement carbonation sink is included), ELUC was 0.9 ± 0.7 GtC yr−1, for a total anthropogenic CO2 emission of 10.2 ± 0.8 GtC yr−1 (37.4 ± 2.9 GtCO2). Also, for 2020, GATM was 5.0 ± 0.2 GtC yr−1 (2.4 ± 0.1 ppm yr−1), SOCEAN was 3.0 ± 0.4 GtC yr−1 and SLAND was 2.9 ± 1 GtC yr−1, with a BIM of −0.8 GtC yr−1. The global atmospheric CO2 concentration averaged over 2020 reached 412.45 ± 0.1 ppm. Preliminary data for 2021, suggest a rebound in EFOS relative to 2020 of +4.9 % (4.1 % to 5.7 %) globally. Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2020, but discrepancies of up to 1 GtC yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows: (1) a persistent large uncertainty in the estimate of land-use changes emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra- tropics, 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 (Friedlingstein et al., 2020; Friedlingstein et al., 2019; Le Quéré et al., 2018b, 2018a, 2016, 2015b, 2015a, 2014, 2013). The data presented in this work are available at https://doi.org/10.18160/gcp-2021 (Friedlingstein et al., 2021)

High prevalence of anemia but low level of iron deficiency in preschool children during a low transmission period of Malaria in rural Kivu, Democratic Republic of the Congo

Anemia is a worldwide public health concern especially in preschool children in developing countries and iron deficiency (ID) is generally assumed to cause at least 50% of the cases. However, data on this contribution are scarce. To close this gap, we determined in 2013 the contribution of ID in the etiology of anemia and measured others factors associated to noniron deficiency anemia (NIDA) in 900 preschool children randomly selected during a two-stage cluster nutritional survey in the Miti-Murhesa health zone, in eastern Democratic Republic of the Congo. In these children, we collected sociodemographic, clinical, and biological parameters and determined the nutritional status according to the World Health Organization 2006 standards. Anemia was defined as altitudeadjusted hemoglobin < 110 g/L and ID was defined as serum ferritin < 12 μg/L or < 30 μg/L in the absence or presence of inflammation, respectively. Median (interquartile range) age was 29.4 (12-45) months. The prevalence of anemiawas 46.6% (391/838) among whom only 16.5% (62/377) had ID. Among children without signs of inflammation, only 4.4%(11/251) met the ferritin-based (unadjusted) definition of ID. Logistic regression analysis identified ID, history of fever during the last 2weeks andmid-upper armcircumference < 125mmas the only independent factors associated to anemia. In conclusion, anemia is a severe public health problem in the Miti-Murhesa health zone, but NIDA is mostly predominant and needs to be further studied. Control of infections and prevention of acute undernutrition (wasting) are some of appropriate interventions to reduce the burden anemia in this region.SCOPUS: ar.jinfo:eu-repo/semantics/publishe