scholarly journals A global CO<sub>2</sub> flux dataset (2015–2019) inferred from OCO-2 retrievals using the Tan-Tracker inversion system

2021 ◽  
Author(s):  
Zhe Jin ◽  
Xiangjun Tian ◽  
Rui Han ◽  
Yu Fu ◽  
Xin Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Carbon Cycle ◽  
Carbon Flux ◽  
Carbon Budget ◽  
Terrestrial Ecosystem ◽  
Carbon Fluxes ◽  
Global Carbon Cycle ◽  
Ocean Carbon ◽  
Global Carbon ◽  
Regional Fluxes

Abstract. Accurate assessment of the various sources and sinks of carbon dioxide (CO2), especially terrestrial ecosystem and ocean fluxes with high uncertainties, is important for understanding of the global carbon cycle, supporting the formulation of climate policies, and projecting future climate change. Satellite retrievals of the column-averaged dry air mole fractions of CO2 (XCO2) are being widely used to improve carbon flux estimation due to their broad spatial coverage. However, there is no consensus on the robust estimates of regional fluxes. In this study, we present a global and regional resolved terrestrial ecosystem carbon flux (NEE) and ocean carbon flux dataset for 2015–2019. The dataset was generated using the Tan-Tracker inversion system by assimilating Observing Carbon Observatory 2 (OCO-2) column CO2 retrievals. The posterior NEE and ocean carbon fluxes were comprehensively validated by comparing posterior simulated CO2 concentrations with OCO-2 independent retrievals and Total Carbon Column Observing Network (TCCON) measurements. The validation showed that posterior carbon fluxes significantly improved the modelling of atmospheric CO2 concentrations, with global mean biases of 0.33 ppm against OCO-2 retrievals and 0.12 ppm against TCCON measurements. We described the characteristics of the dataset at global, regional, and Tibetan Plateau scales in terms of the carbon budget, annual and seasonal variations, and spatial distribution. The posterior 5-year annual mean global atmospheric CO2 growth rate was 5.35 PgC yr−1, which was within the uncertainty of the Global Carbon Budget 2020 estimate (5.49 PgC yr−1). The posterior annual mean NEE and ocean carbon fluxes were −4.07 and −3.33 PgC yr−1, respectively. Regional fluxes were analysed based on TransCom partitioning. All 11 land regions acted as carbon sinks, except for Tropical South America, which was almost neutral. The strongest carbon sinks were located in Boreal Asia, followed by Temperate Asia and North Africa. The entire Tibetan Plateau ecosystem was estimated as a carbon sink, taking up −49.52 TgC yr−1 on average, with the strongest sink occurring in eastern alpine meadows. These results indicate that our dataset captures surface carbon fluxes well and provides insight into the global carbon cycle. The dataset can be accessed at https://doi.org/10.11888/Meteoro.tpdc.271317 (Jin et al., 2021).

scholarly journals Two aspects of decadal ENSO variability modulating the long-term global carbon cycle

2020 ◽  
Author(s):  
So-won Park ◽  
Jin-Soo Kim ◽  
Jong-Seong Kug ◽  
Malte F. Stuecker ◽  
In-Won Kim ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbon Flux ◽  
Decadal Variability ◽  
Southern Oscillation ◽  
Terrestrial Ecosystem ◽  
Global Carbon Cycle ◽  
Terrestrial Carbon ◽  
Enso Variability ◽  
Global Carbon

&lt;p&gt;El Ni&amp;#241;o-Southern Oscillation (ENSO) is the primary cause of interannual variations in the global carbon cycle because ENSO-driven extensive teleconnection over continents affects the terrestrial ecosystem process. ENSO is an interannual phenomenon, but it also has decadal variability. The ENSO-like SST pattern and ENSO characteristic, e.g. ENSO amplitude, change on decadal timescales. However, the influence of decadal ENSO variability on global carbon cycle has not yet been fully examined. Here we examined the impacts of decadal ENSO variability on decadal variation of terrestrial carbon flux by analyzing fully coupled pre-industrial control simulation of the Community Earth System Model 1 large ensemble (CESM1-LE). Considerable decadal variability of atmosphere-to-land carbon flux exists and this terrestiral carbon flux is mainly modulated by the tropical biosphere on decadal timescales as well as on interannual timescales. We found that there are two different pathways, which can explain about 36% of the decadal variations in terrestrial carbon flux. First, long-term climate change over tropics induced by decadal tropical Pacific SST variability regulates the terrestrial productivity and hence atmospheric CO&lt;sub&gt;2&lt;/sub&gt; on decadal time scale. Second, decadal changes in asymmetric terrestrial ecosystem&amp;#8217;s response to ENSO events, resulted from decadal modulation of ENSO amplitude, generate decadal variability of terrestrial carbon flux.&lt;/p&gt;&lt;p&gt;Key words: Global Carbon Cycle, El Ni&amp;#241;o-Southern Oscillation (ENSO), Pacific Decadal Variability, ENSO asymmetry, Decadal NBP variability&lt;/p&gt;

scholarly journals Projected changes of alpine grassland carbon dynamics in response to climate change and elevated CO2concentrations under Representative Concentration Pathways (RCP) scenarios

2019 ◽  
Author(s):  
Pengfei Han ◽  
Xiaohui Lin ◽  
Wen Zhang ◽  
Guocheng Wang
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Carbon Cycle ◽  
Carbon Budget ◽  
Carbon Fluxes ◽  
Carbon Dynamics ◽  
Alpine Grassland ◽  
The Tibetan Plateau ◽  
Rcp Scenarios ◽  
Representative Concentration Pathways

AbstractThe Tibetan Plateau is an important component of the global carbon cycle due to the large permafrost carbon pool and its vulnerability to climate warming. The Tibetan Plateau has experienced a noticeable warming over the past few decades and is projected to continue warming in the future. However, the direction and magnitude of carbon fluxes responses to climate change and elevated CO2concentration under Representative Concentration Pathways (RCP) scenarios in the Tibetan Plateau grassland are poorly known. Here, we used a calibrated and validated biogeochemistry model, CENTURY, to quantify the contributions of climate change and elevated CO2on the future carbon budget in the alpine grassland under three RCP scenarios. Though the Tibetan Plateau grassland was projected a net carbon sink of 16 ~ 25 Tg C yr-1in the 21st century, the capacity of carbon sequestration was predicted to decrease gradually because climate-driven increases in heterotrophic respiration (Rh) (with linear slopes 0.49 ~ 1.62 g C m-2yr-1) was greater than the net primary production (NPP) (0.35 ~ 1.52 g C m-2yr-1). However, the elevated CO2contributed more to plant growth (1.9% ~ 7.3%) than decomposition (1.7% ~ 6.1%), which could offset the warming-induced carbon loss. The interannual and decadal-scale dynamics of the carbon fluxes in the alpine grassland were primarily controlled by temperature, while the role of precipitation became increasingly important in modulating carbon cycle. The strengthened correlation between precipitation and carbon budget suggested that further research should consider the performance of precipitation in evaluating carbon dynamics in a warmer climate scenario.

scholarly journals The global carbon budget 1959–2011

2013 ◽  
Vol 5 (1) ◽  
pp. 165-185 ◽  
Author(s):  
C. Le Quéré ◽  
R. J. Andres ◽  
T. Boden ◽  
T. Conway ◽  
R. A. Houghton ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Cycle ◽  
Co2 Emissions ◽  
Carbon Budget ◽  
Co2 Concentration ◽  
Global Carbon Cycle ◽  
Atmospheric Co2 ◽  
Global Carbon Budget ◽  
Atmospheric Co2 Concentration ◽  
Global Carbon

Abstract. Accurate assessments of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the climate policy process, and project future climate change. Present-day analysis requires the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. Here we describe datasets and a methodology developed by the global carbon cycle science community to quantify all major components of the global carbon budget, including their uncertainties. We discuss changes compared to previous estimates, consistency within and among components, and methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics, while emissions from Land-Use Change (ELUC), including deforestation, are based on combined evidence from land cover change data, fire activity in regions undergoing deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. Finally, the global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms. For the last decade available (2002–2011), EFF was 8.3 &amp;pm; 0.4 PgC yr−1, ELUC 1.0 &amp;pm; 0.5 PgC yr−1, GATM 4.3 &amp;pm; 0.1 PgC yr−1, SOCEAN 2.5 &amp;pm; 0.5 PgC yr−1, and SLAND 2.6 &amp;pm; 0.8 PgC yr−1. For year 2011 alone, EFF was 9.5 &amp;pm; 0.5 PgC yr−1, 3.0 percent above 2010, reflecting a continued trend in these emissions; ELUC was 0.9 &amp;pm; 0.5 PgC yr−1, approximately constant throughout the decade; GATM was 3.6 &amp;pm; 0.2 PgC yr−1, SOCEAN was 2.7 &amp;pm; 0.5 PgC yr−1, and SLAND was 4.1 &amp;pm; 0.9 PgC yr−1. GATM was low in 2011 compared to the 2002–2011 average because of a high uptake by the land probably in response to natural climate variability associated to La Niña conditions in the Pacific Ocean. The global atmospheric CO2 concentration reached 391.31 &amp;pm; 0.13 ppm at the end of year 2011. We estimate that EFF will have increased by 2.6% (1.9–3.5%) in 2012 based on projections of gross world product and recent changes in the carbon intensity of the economy. All uncertainties are reported as &amp;pm;1 sigma (68% confidence assuming Gaussian error distributions that the real value lies within the given interval), reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. This paper is intended to provide a baseline to keep track of annual carbon budgets in the future. All data presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_V2013). Global carbon budget 2013

Reconstructions and predictions of the global carbon cycle with an emission-driven Earth System Model

2021 ◽  
Author(s):  
Hongmei Li ◽  
Tatiana Ilyina ◽  
Tammas Loughran ◽  
Julia Pongratz
Keyword(s):  
Growth Rate ◽  
Carbon Cycle ◽  
Carbon Budget ◽  
Global Carbon Cycle ◽  
System Model ◽  
Earth System ◽  
Global Carbon Budget ◽  
Predictive Skill ◽  
Atmospheric Carbon ◽  
Global Carbon

&lt;p&gt;The global carbon budget including CO&lt;sub&gt;2&lt;/sub&gt; fluxes among different reservoirs and atmospheric carbon growth rate vary substantially in interannual to decadal time-scales. Reconstructing and predicting the variable global carbon cycle is of essential value of tracing the fate of carbon and the corresponding climate and ecosystem changes. For the first time, we extend our prediction system based on the Max Planck Institute Earth system model (MPI-ESM) from concentration-driven to emission-driven taking into account the interactive carbon cycle and hence enabling prognostic atmospheric carbon increment.&amp;#160;&lt;/p&gt;&lt;p&gt;By assimilating atmospheric and oceanic observational data products into MPI-ESM decadal prediction system, we can reproduce the observed variations of the historical global carbon cycle globally. The reconstruction from the fully coupled model enables quantification of global carbon budget within a close Earth system and therefore avoids the budget imbalance term of budgeting the carbon with standalone models. Our reconstructions of carbon budget provide a novel approach for supporting global carbon budget and understanding the dominating processes. Retrospective predictions based on the &amp;#160;emission-driven hindcasts, which are initiated from the reconstructions, show predictive skill in the atmospheric carbon growth rate, air-sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes, and air-land CO&lt;sub&gt;2&lt;/sub&gt; fluxes. The air-sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes have higher predictive skill up to 5 years, and the air-land CO&lt;sub&gt;2&lt;/sub&gt; fluxes and atmospheric carbon growth rate show predictive skill of 2 years. Our results also suggest predictions based on Earth system models enable reproducing and further predicting the evolution of atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentration changes. The earth system predictions will provide valuable inputs for understanding the global carbon cycle and supporting climate relevant policy development.&amp;#160;&lt;/p&gt;

Plumbing the Global Carbon Cycle: Integrating Inland Waters into the Terrestrial Carbon Budget

Ecosystems ◽  
2007 ◽  
Vol 10 (1) ◽  
pp. 172-185 ◽  
Author(s):  
J. J. Cole ◽  
Y. T. Prairie ◽  
N. F. Caraco ◽  
W. H. McDowell ◽  
L. J. Tranvik ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbon Budget ◽  
Global Carbon Cycle ◽  
Inland Waters ◽  
Terrestrial Carbon ◽  
Global Carbon

Human induced changes in the carbon cycle over the last 60 years

2021 ◽  
Author(s):  
Pierre Friedlingstein
Keyword(s):  
Carbon Cycle ◽  
Fossil Fuel ◽  
Deep Ocean ◽  
Global Carbon Cycle ◽  
Atmospheric Co2 ◽  
Carbon Sinks ◽  
Modelling Studies ◽  
Ocean Carbon ◽  
Global Emissions ◽  
Global Carbon

&lt;p&gt;Human activities have an unprecedented impact on the global carbon cycle. &amp;#160;Atmospheric CO2 concentrations have been continuously monitored since 1958, and show a 30% increase, from 315 ppm in 1958 to 412 ppm in 2020. Anthropogenic emissions, primarily from fossil fuel combustion, but also from land-use changes, are the drivers of these changes, with global emissions almost tripling over that period, from 4GtC per year in 1958 to almost 12 GtC per year at present. Although fossil fuel emission declined by about 7% in 2020 due to response to the COVID-19 pandemic, there are no long-term sign of global emissions declining yet, despite climate policies being put in places in many countries.&lt;/p&gt;&lt;p&gt;The atmospheric CO2 increase induces land and ocean carbon uptake, respectively driven by enhanced photosynthesis, leading to larger land biomass and soil carbon; and by enhanced air-sea CO2 exchange, leading to larger carbon content in the surface ocean and export to the deep ocean. These mechanisms are negative feedbacks in the Earth system and are removing about 50% of the CO2 emitted in the atmosphere. Without these land and ocean carbon sinks, current atmospheric CO2 would already be around 600 ppm.&lt;/p&gt;&lt;p&gt;However, modelling studies show that climate change reduces land and ocean carbon sinks, hence amplifying the warming. Although there is agreement that such positive feedback will develop over the course of the century, there are not yet clear evidence of a major climate driven reduction of the carbon sinks.&amp;#160; So far, observations and modelling studies of the historical carbon cycle do not show any sign of a tipping point in the global carbon cycle.&lt;/p&gt;

Human induced changes on the global carbon cycle over the last 60 years

2020 ◽  
Author(s):  
Pierre Friedlingstein
Keyword(s):  
Carbon Cycle ◽  
Fossil Fuel ◽  
Global Carbon Cycle ◽  
Atmospheric Co2 ◽  
Carbon Sinks ◽  
Rate Of Increase ◽  
Modelling Studies ◽  
Ocean Carbon ◽  
Global Emissions ◽  
Global Carbon

&lt;p&gt;Human activities have an unprecedented impact on the global carbon cycle. &amp;#160;Atmospheric CO2 concentrations have been continuously monitored since 1958, and show a 30% increase, from 315 ppm in 1958 to 411 ppm in 2019. Anthropogenic emissions, primarily from fossil fuel combustion, but also from land-use changes, are the drivers of these changes, with global emissions almost tripling over that period, from 4GtC per year in 1958 to almost 12 GtC per year at present. Although the current rate of increase in fossil fuel emission of about 1% per year is lower than over the 2000s (about 3.0 % per year), there are no sign of global emissions peaking yet, despite climate policies being put in places in many countries.&lt;/p&gt;&lt;p&gt;The atmospheric CO2 increase induces land and ocean carbon uptake, respectively driven by enhanced photosynthesis, leading to larger land biomass and soil carbon; and by enhanced air-sea CO2 exchange, leading to larger carbon content in the surface ocean and export to the deep ocean. These mechanism are negative feedbacks in the Earth system and are removing about 50% of the CO2 emitted in the atmosphere. Without these land and ocean carbon sinks, atmospheric CO2 would already be about 600 ppm.&lt;/p&gt;&lt;p&gt;However, modelling studies show that climate change reduces land and ocean carbon sinks, hence amplifying the warming. Although there is agreement that such positive feedback will develop over the course of the century, there are not yet clear evidences of a major climate driven reduction of the carbon sinks.&amp;#160; So far, observations and modelling studies of the historical carbon cycle do not show any sign of a tipping point in the global carbon cycle.&lt;/p&gt;

scholarly journals The global carbon budget 1959–2011

2012 ◽  
Vol 5 (2) ◽  
pp. 1107-1157 ◽  
Author(s):  
C. Le Quéré ◽  
R. J. Andres ◽  
T. Boden ◽  
T. Conway ◽  
R. A. Houghton ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Cycle ◽  
Co2 Emissions ◽  
Carbon Budget ◽  
Global Carbon Cycle ◽  
Data Availability ◽  
Future Climate Change ◽  
Global Carbon Budget ◽  
Co2 Sink ◽  
Global Carbon

Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the climate policy process, and project future climate change. Present-day analysis requires the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. Here we describe datasets and a methodology developed by the global carbon cycle science community to quantify all major components of the global carbon budget, including their uncertainties. We discuss changes compared to previous estimates, consistency within and among components, and methodology and data limitations. Based on energy statistics, we estimate that the global emissions of CO2 from fossil fuel combustion and cement production were 9.5 ± 0.5 PgC yr−1 in 2011, 3.0 percent above 2010 levels. We project these emissions will increase by 2.6% (1.9–3.5%) in 2012 based on projections of Gross World Product and recent changes in the carbon intensity of the economy. Global net CO2 emissions from Land-Use Change, including deforestation, are more difficult to update annually because of data availability, but combined evidence from land cover change data, fire activity in regions undergoing deforestation and models suggests those net emissions were 0.9 ± 0.5 PgC yr−1 in 2011. The global atmospheric CO2 concentration is measured directly and reached 391.38 ± 0.13 ppm at the end of year 2011, increasing 1.70 ± 0.09 ppm yr−1 or 3.6 ± 0.2 PgC yr−1 in 2011. Estimates from four ocean models suggest that the ocean CO2 sink was 2.6 ± 0.5 PgC yr−1 in 2011, implying a global residual terrestrial CO2 sink of 4.1 ± 0.9 PgC yr−1. All uncertainties are reported as ±1 sigma (68% confidence assuming Gaussian error distributions that the real value lies within the given interval), reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. This paper is intended to provide a baseline to keep track of annual carbon budgets in the future. All carbon data presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_V2012).

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