scholarly journals The Impact of Agricultural Soil Erosion on the Global Carbon Cycle

Science ◽  
2007 ◽  
Vol 318 (5850) ◽  
pp. 626-629 ◽  
Author(s):  
K. Van Oost ◽  
T. A. Quine ◽  
G. Govers ◽  
S. De Gryze ◽  
J. Six ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Carbon Cycle ◽  
Agricultural Soil ◽  
Large Scale ◽  
Carbon Sink ◽  
Global Carbon Cycle ◽  
Agricultural Landscapes ◽  
Carbon Equivalent ◽  
The Impact ◽  
Global Carbon

Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 petagram per year–1to a sink of the same magnitude. By using caesium-137 and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced sink of atmospheric carbon equivalent to approximately 26% of the carbon transported by erosion. Based on this relationship, we estimated a global carbon sink of 0.12 (range 0.06 to 0.27) petagrams of carbon per year–1resulting from erosion in the world's agricultural landscapes. Our analysis directly challenges the view that agricultural erosion represents an important source or sink for atmospheric CO2.

Agricultural soil erosion and global carbon cycle: controversy over?

2009 ◽  
pp. n/a-n/a ◽  
Author(s):  
Nikolaus J. Kuhn ◽  
Thomas Hoffmann ◽  
Wolfgang Schwanghart ◽  
Markus Dotterweich
Keyword(s):  
Soil Erosion ◽  
Carbon Cycle ◽  
Agricultural Soil ◽  
Global Carbon Cycle ◽  
Global Carbon

scholarly journals Amazonian Fire Events Disturbed the Global Carbon Cycle: A Study from 2019 Amazon Wildfire Using Google Earth Engine

2020 ◽  
Vol 3 (1) ◽  
pp. 43
Author(s):  
Subhajit Bandopadhyay ◽  
Dany A. Cotrina Sánchez
Keyword(s):  
Carbon Cycle ◽  
Carbon Sink ◽  
Brazilian Amazon ◽  
Global Carbon Cycle ◽  
Forest Productivity ◽  
Google Earth ◽  
Comparative Approach ◽  
Burned Area ◽  
Google Earth Engine ◽  
Global Carbon

An unprecedented number of wildfire events during 2019 throughout the Brazilian Amazon caught global attention, due to their massive extent and the associated loss in the Amazonian forest—an ecosystem on which the whole world depends. Such devastating wildfires in the Amazon has strongly hampered the global carbon cycle and significantly reduced forest productivity. In this study, we have quantified such loss of forest productivity in terms of gross primary productivity (GPP), applying a comparative approach using Google Earth Engine. A total of 12 wildfire spots have been identified based on the fire’s extension over the Brazilian Amazon, and we quantified the loss in productivity between 2018 and 2019. The Moderate Resolution Imaging Spectroradiometer (MODIS) GPP and MODIS burned area satellite imageries, with a revisit time of 8 days and 30 days, respectively, have been used for this study. We have observed that compared to 2018, the number of wildfire events increased during 2019. But such wildfire events did not hamper the natural annual trend of GPP of the Amazonian ecosystem. However, a significant drop in forest productivity in terms of GPP has been observed. Among all 11 observational sites were recorded with GPP loss, ranging from −18.88 gC m−2 yr−1 to −120.11 gC m−2 yr−1, except site number 3. Such drastic loss in GPP indicates that during 2019 fire events, all of these sites acted as carbon sources rather than carbon sink sites, which may hamper the global carbon cycle and terrestrial CO2 fluxes. Therefore, it is assumed that these findings will also fit for the other Amazonian wildfire sites, as well as for the tropical forest ecosystem as a whole. We hope this study will provide a significant contribution to global carbon cycle research, terrestrial ecosystem studies, sustainable forest management, and climate change in contemporary environmental sciences.

Basalt weathering laws and the impact of basalt weathering on the global carbon cycle

2003 ◽  
Vol 202 (3-4) ◽  
pp. 257-273 ◽  
Author(s):  
Céline Dessert ◽  
Bernard Dupré ◽  
Jérôme Gaillardet ◽  
Louis M. François ◽  
Claude J. Allègre
Keyword(s):  
Carbon Cycle ◽  
Global Carbon Cycle ◽  
Basalt Weathering ◽  
The Impact ◽  
Global Carbon

scholarly journals Comment on "Carbon farming in hot, dry coastal areas: an option for climate change mitigation" by Becker et al. (2013)

2013 ◽  
Vol 4 (2) ◽  
pp. 869-873
Author(s):  
M. Heimann
Keyword(s):  
Carbon Cycle ◽  
Carbon Sink ◽  
Co2 Concentration ◽  
Global Carbon Cycle ◽  
Atmospheric Co2 ◽  
Reference Scenario ◽  
Carbon Cycle Model ◽  
Terrestrial Carbon Sink ◽  
Carbon Dioxide Co2 ◽  
Global Carbon

Abstract. Becker et al. (2013) argue that an afforestation of 0.73 109 ha with Jatropha curcas plants would generate an additional terrestrial carbon sink of 4.3 PgC yr−1, enough to stabilise the atmospheric mixing ratio of carbon dioxide (CO2) at current levels. However, this is not consistent with the dynamics of the global carbon cycle. Using a well established global carbon cycle model, the effect of adding such a hypothetical sink leads to a reduction of atmospheric CO2 levels in the year 2030 by 25 ppm compared to a reference scenario. However, the stabilisation of the atmospheric CO2 concentration requires a much larger additional sink or corresponding reduction of anthropogenic emissions.

scholarly journals Organic Geochemical Characteristics of the Upper Cretaceous Qingshankou Formation Oil Shales in the Fuyu Oilfield, Songliao Basin, China: Implications for Oil-Generation Potential and Depositional Environment

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4778 ◽  
Author(s):  
Wentong He ◽  
Youhong Sun ◽  
Wei Guo ◽  
Xuanlong Shan ◽  
Siyuan Su ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Cycle ◽  
Depositional Environment ◽  
Global Carbon Cycle ◽  
Songliao Basin ◽  
Oil Generation ◽  
Oil Shales ◽  
Extractable Organic Matter ◽  
The Impact ◽  
Global Carbon

The Cretaceous Era has always been a focus of geologic and palaeoenvironmental studies. Previous researchers believed that the impact of the global carbon cycle represents significant short-term global biogeochemical fluctuations, leading to the formation of a large number of organic rich sediments in the marine environment. During the Turonian, a large number of organic-rich oil shales were deposited in the lakes of the Songliao Basin in the Qingshankou Formation. How the depositional environment affected the formation of oil shales in continental lakes and the characteristics of these oil shales remain controversial. In this paper, through sampling of Qingshankou Formation strata, various testing methods are used to provide a variety of new data to study the characteristics of oil shales and palaeoenvironment evolution history in the Songliao Basin. The research of the sediments in the Qingshankou Formation in the Fuyu oilfield, Songliao Basin, via result analysis revealed that the oil shales possess an excellent oil-generation potential with moderate-high total organic carbon (TOC) levels (0.58–9.43%), high hydrogen index (HI) values (265–959 mg hydrocarbons (HC)/g TOC), high extractable organic matter (EOM) levels (2.50–6.96 mg/g TOC) and high hydrocarbon fractions (48–89%). The sources of the organic matter were mainly zooplankton, red algae and higher plants (including marine organisms). The aqueous palaeoenvironment of the Qingshankou Formation was a saline water environment with a high sulfate concentration, which promoted an increase in nutrients and stratification of the water density in the lake basin. Oxygen consumption in the bottom water layer promoted the accumulation and burial of high-abundance organic matter, thus forming the high-quality oil shales in the Qingshankou Formation. The global carbon cycle, warm-humid palaeoclimate, dynamic local biogeochemical cycling and relative passive tectonism were the most likely reasons for the TOC increase and negative δ13Corg deviation.

scholarly journals Assessment of carbon dynamics in Ecuadorian forests through the Mathematical Spatial Model of Global Carbon Cycle and the Normalized Differential Vegetation Index (NDVI)

2019 ◽  
Vol 96 ◽  
pp. 02002
Author(s):  
Llerena Silvia ◽  
Tarko Alexander ◽  
Kurbatova Anna ◽  
Kozhevnikova Polina
Keyword(s):  
Carbon Cycle ◽  
Spatial Model ◽  
Vegetation Index ◽  
Carbon Sink ◽  
Anthropogenic Impacts ◽  
Global Carbon Cycle ◽  
Biomass Estimation ◽  
Vegetation Map ◽  
Deforestation Rate ◽  
Global Carbon

Conservation and sustainable development of forests are mitigation mechanisms against climate change due to the forest carbon sink capacity. Therefore, biomass estimation allows to assess forest productivity and control carbon budgets. In Ecuador, biomass and carbon sequestration studies are scarce. Thus, we estimated and forecasted changes in biomass of Ecuadorian forests through the Mathematical Spatial Model of Global Carbon Cycle and the Normalized Differential Vegetation Index. The mathematical model describes the processes of growth and decay of vegetation in terms of carbon exchange between the atmosphere, plants and soil under anthropogenic impacts. The vegetation map and the biomass of 2017 (4,86 Gt) were developed with remote sensing methodology in ENVI 5.3 and ArcGIS 10.3 programs. The observed biomass decrease between 2000 and 2010 was due to the high deforestation rate. Thanks to conservation and reforestation policies and the compensatory effect between the atmosphere and forests, a biomass increase is expected until 2060. According to the vegetation map, Amazon region has a better plant vigor, followed by Andean and Coast regions, where scattered vegetation predominates. This information is useful for planning environmental practices such as forest conservation and reforestation in order to increase carbon storage.

scholarly journals Comment on "Carbon farming in hot, dry coastal areas: an option for climate change mitigation" by Becker et al. (2013)

2014 ◽  
Vol 5 (1) ◽  
pp. 41-42 ◽  
Author(s):  
M. Heimann
Keyword(s):  
Carbon Cycle ◽  
Carbon Sink ◽  
Co2 Concentration ◽  
Global Carbon Cycle ◽  
Atmospheric Co2 ◽  
Reference Scenario ◽  
Carbon Cycle Model ◽  
Terrestrial Carbon Sink ◽  
Carbon Dioxide Co2 ◽  
Global Carbon

Abstract. Becker et al. (2013) argue that an afforestation of 0.73 × 109 ha with Jatropha curcas plants would generate an additional terrestrial carbon sink of 4.3 PgC yr−1, enough to stabilise the atmospheric mixing ratio of carbon dioxide (CO2) at current levels. However, this is not consistent with the dynamics of the global carbon cycle. Using a well-established global carbon cycle model, the effect of adding such a hypothetical sink leads to a reduction of atmospheric CO2 levels in the year 2030 by 25 ppm compared to a reference scenario. However, the stabilisation of the atmospheric CO2 concentration requires a much larger additional sink or corresponding reduction of anthropogenic emissions.

scholarly journals The impact of different external sources of iron on the global carbon cycle

2014 ◽  
Vol 41 (3) ◽  
pp. 920-926 ◽  
Author(s):  
Alessandro Tagliabue ◽  
Olivier Aumont ◽  
Laurent Bopp
Keyword(s):  
Carbon Cycle ◽  
Global Carbon Cycle ◽  
External Sources ◽  
The Impact ◽  
Global Carbon

scholarly journals Increasing Autochthonous Production in Inland Waters as a Contributor to the Missing Carbon Sink

2021 ◽  
Vol 9 ◽  
Author(s):  
Zaihua Liu ◽  
Hao Yan ◽  
Sibo Zeng
Keyword(s):  
Organic Carbon ◽  
Carbon Cycle ◽  
Carbon Sink ◽  
Global Carbon Cycle ◽  
Inland Waters ◽  
Organic Carbon Burial ◽  
Missing Carbon Sink ◽  
Organic Carbon Storage ◽  
Autochthonous Production ◽  
Global Carbon

Accounting for the residual land sink (or missing carbon sink) has become a major budget focus for global carbon cycle modelers. If we are not able to account for the past and current sources and sinks, we cannot make accurate predictions about future storage of fossil fuel combustion emissions of carbon in the terrestrial biosphere. Here, we show that the autochthonous production (AP) in inland waters appears to have been strengthening in response to changes in climate and land use, as evidenced by decreasing CO2 emissions from and increasing dissolved organic carbon storage and/or organic carbon burial in inland waters during recent decades. The increasing AP may be due chiefly to increasing aquatic photosynthesis caused by global warming and intensifying human activities. We estimate that the missing carbon sink associated with the strengthening AP in inland waters may range from 0.38 to 1.8 Gt C yr-1 with large uncertainties. Our study stresses the potential role that AP may play in the further evolution of the global carbon cycle. Quantitative estimates of future freshwater AP effects on the carbon cycle may also help to guide the action needed to reduce carbon emissions, and increase carbon sinks in terrestrial aquatic ecosystems.

Revisiting groundwater carbon fluxes to the ocean with implications for the carbon cycle

Geology ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 67-71 ◽  
Author(s):  
Shuang Zhang ◽  
Noah J. Planavsky
Keyword(s):  
United States ◽  
Carbon Cycle ◽  
Carbon Sink ◽  
Groundwater Discharge ◽  
Global Carbon Cycle ◽  
The United States ◽  
Silicate Weathering ◽  
Fresh Groundwater ◽  
Discharge Rates ◽  
Global Carbon

Abstract Compared with riverine systems, the influence of groundwater on the global carbon cycle has remained underexplored. Here, we provide a new estimate of the bicarbonate fluxes from fresh groundwater to the ocean by coupling a statistical and hydrological analysis of groundwater and river samples across the contiguous United States with a study of global groundwater characteristics. We find that the mean concentration ([]) in groundwaters exceeds that in surface rivers by a factor of 2–3 throughout the contiguous United States. Based on estimates of fresh groundwater discharge to the ocean and scaling up our estimated mean [] in groundwaters from the United States and around the world, we arrived at a mean global flux from groundwaters ranging from 7.4 × 1012 (25th percentile)–1.8 × 1013 mol/yr (75th percentile) to 2.8 × 1013–8.3 × 1013 mol/yr, which is 22%–237% of the global flux from river systems, respectively. We also estimated that the global carbon flux derived from subsurface silicate weathering could be comparable to 32%–351% that from surficial silicate weathering, depending on groundwater discharge rates. Despite large uncertainties due to data limitation, this study highlights that groundwater weathering could be an important carbon sink in both the short- and long-term carbon cycle. Therefore, additional work on groundwaters is needed to develop a well-constrained view of the global carbon cycle.

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