Carbon Transfer Research Articles

Study on the characteristics of embodied carbon emission transfer in China’s power sector based on input-output networks

Electricity is an essential factor of production. The trade of goods and services between different industrial sectors in different regions may lead to the transfer of embodied carbon emissions in the power sector, which makes the problem of “carbon leakage” widespread. As the world’s largest CO2 emitter, China’s systematic identification of the patterns and structural characteristics of embodied carbon transfer in its power sector is essential for reasonably defining emission reduction responsibilities and scientifically formulating emission reduction policies. Few studies have focused on interprovincial transfer characteristics of embodied carbon emissions in the power sector. Based on the multi-regional input-output tables of China in 2010, 2012, 2015, and 2017, this paper combined the complex network theory to construct the interprovincial power embodied carbon transfer networks (PECTNs1) of China, analyzed the topological nature, community structure and identified the key provinces in the networks with the help of complex network indicators. The results indicate that both direct and embodied carbon emissions from China’s power sector present an increasing trend during the study period. The scale and scope of power carbon emission transfer between provinces have been expanding, showing an transfer trend from west to east and north to south. China’s PECTNs have small-world characteristics. From 2010 to 2017, the sub-regional phenomenon in China’s PECTNs gradually decreased. In the network community, the provinces with stable relationships are close to each other and have closer carbon correlation. Coal resource-based and large economic provinces with high power demand tend to be the core of the networks. The position of Xinjiang in the networks is gradually prominent. According to the results of the study, differentiated carbon emission reduction schemes are formulated based on the roles played by different provinces to provide ideas for embodied carbon reduction among provinces in China’s power sector.

Embodied carbon transfers and employment-economic spillover effects in China’s inter-provincial trade

Understanding the embodied carbon transfer in inter-provincial trade and its employment-economic spillover effects is of crucial value in achieving carbon equity management. Surprisingly, few studies have focused on the intrinsic relationship between embodied carbon, embodied GDP, and embodied employment in iinter-provincial trade and its equity implications. Based on the 2012 and 2017 multi-regional input-output tables, our study of inter-provincial trade in 30 Chinese provinces shows that: 1) net outflows of embodied carbon were concentrated in the Beijing-Tianjin region and the eastern and southern coastal regions, while net inflows were in the central and northwestern regions; 2) embodied carbon, GDP, and employment were characterized by nearby transfer, complementary energy economy, and asymmetric transfers in and out; and 3) western provinces, which relied heavily on traditional energy and heavy chemical industries, gained a competitive disadvantage implying by the internal relationship between net transfers of embodied carbon, GDP, and employment. To mitigate the inequity of inter-provincial carbon trade, top-down climate goals must be aligned with bottom-up socio-economic incentives to achieve balanced regional development and improved public welfare.

A first estimate of the effect of offshore wind farms on sedimentary organic carbon stocks in the Southern North Sea

Offshore wind farms (OWFs) can increase the transfer and stock of organic carbon (OC) in the surrounding sediments during their operational phase, while their construction and decommissioning release carbon. To answer the question whether sediments of OWFs trap more OC than they release, we estimate the net carbon effect over the entire life cycle (construction, operational and decommissioning phases) of OWFs in the Southern North Sea. Based on existing studies we compare the increased OC flux due to the colonization of organisms at the foundations of wind turbines and the OC loss due to sediment-disturbing activities during construction and decommissioning. Our results show that the areal intensity of carbon release in the disturbed areas is about 43.5 times higher than that of carbon trapping in the entire area of the OWFs. However, since the disturbed areas only account for about 0.50 ± 0.06% of the total area of the OWFs, in absolute terms about 4.6 ± 1.4 times more carbon is trapped in the sediment of the OWFs than is released. Due to limited data availability and the resulting need for extensive assumptions, our estimates only represent orders of magnitude. We therefore provide sensitivity estimates that define the limits of our calculations in terms of disturbance depth, remineralisation ratio, scour protection measures and heterogenous OC contents. In addition, we identify shortcomings of our extrapolation. Further research, especially more advanced impact assessments of construction and decommissioning processes must follow to improve the understanding of impacts of OWFs on sedimentary OC.

Influence of Nutrient Gradient on Phytoplankton Size Structure, Primary Production and Carbon Transfer Pathway in a Highly Productive Area (SE Mediterranean)

Influence of Nutrient Gradient on Phytoplankton Size Structure, Primary Production and Carbon Transfer Pathway in a Highly Productive Area (SE Mediterranean)

The rising North-South carbon flows within China from 2012 to 2017

The carbon transfer changes triggered by transformation of economic development patterns are less concerned. This study seeks to estimate the carbon implications caused by regional development gaps between the North and South in China. We utilize Multiregional Input-Output (MRIO) model to reveal the new features of embodied carbon emission, and apply structural decomposition analysis (SDA) to reflect the main driving forces behind the changes in implied emissions patterns. The results demonstrate that carbon transfers show a significant trend from the North to the South in 2017. Moreover, electricity and heat power, metal and non-metal industries in poorer northern regions are the important “suppliers” of implied emissions, while construction and service industries in developed southern regions are the main “consumers”. Carbon transfers from the North to the South mainly due to changes in consumption and export. The key industries and driving forces should receive more attention when making carbon reduction policies.

中国区域间贸易碳转移特征及其对碳中和的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 中国区域间贸易碳转移特征及其对碳中和的影响 DOI: 10.5846/stxb202108082170 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目(2019YFC0507801) Carbon transfer characteristics and its effect on carbon neutrality of China's inter-regional trade Author: Affiliation: Fund Project: National Key Research and Development Program of China （Grant No.2019YFC0507801） 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:优化贸易模式对实现"碳达峰,碳中和"这一中长期计划至关重要。基于多区域投入产出模型和碳生态承载力模型,分析了我国2017年30个省份(本研究不含中国港澳台和西藏的统计数据)碳足迹和碳生态承载力剩余量的空间分布特征。研究表明:(1)经济或人口总量较大的省份(如广东、江苏、河南等)碳足迹较大,而万元GDP碳足迹较大的省份主要分布在西部和东北地区,虚拟碳主要是向经济发达的省份转移。(2)总体上,中国的区域间贸易不具备碳中和特征,但就地区而言,区域间贸易使得山西、内蒙古、辽宁、宁夏、新疆地区碳足迹有所降低,但碳中和程度较低(<20%);就行业而言,建筑业贸易的碳中和特征最为明显,特别是在东北三省。(3)经济富裕的几个省份碳减排压力较大,如:北京、天津等地的碳生态承载力出现赤字,而黑龙江、河南、吉林、山东碳生态承载力剩余量超过10×108 t,碳减排压力较小。未来在制定相关政策时,应综合考虑省际间碳的转移特征,合理分配碳排放定额,以保障碳排放权交易市场的顺利运行。 Abstract:Human activities lead to global climate change, such as the greenhouse effect, heat island effect, global warming, glacier melting, sea-level rise, and so on. Among them, the global warming caused by the increase of greenhouse gas emissions has a great impact on human production and life. To control greenhouse gas emissions, many countries are exploring various ways to reduce carbon emissions, and hope to achieve the goal of "carbon neutrality" in the planned time. China is also one of them, our country has formulated a medium-and long-term plan to achieve carbon neutrality and is exploring ways to achieve this goal, such as adjusting the industrial and energy consumption structure, and changing the way of production and life. With the development of China's economy, regional trade interactions are frequent, and reducing carbon emissions through optimizing trade patterns should not be ignored. However, such studies are relatively few at present, and the carbon-neutral characteristics of trade in each province are not clear yet. This paper, based on the multi-regional input-output model, carbon-neutral model, and carbon ecological footprint model, analyzed the spatial distribution of carbon footprint, carbon transfer characteristics, and carbon ecological carrying capacity surplus of 30 Chinese provinces in 2017. Our results show that (1) provinces with larger populations or richer economies have larger carbon footprints, such as Guangdong, Jiangsu, and Henan, while in the provinces of western and northeastern China, the carbon footprints of 10000 yuan GDP are relatively larger. Virtual carbon is mainly transferred to economically affluent provinces. (2) For different provinces and sectors, the carbon-neutral characteristics of trade vary considerably. For the provinces, the trade reduced the carbon footprint in Shanxi, Inner Mongolia, Liaoning, Ningxia, and Xingjiang, but the degree of carbon neutrality is relatively low (< 20%). As far as the sectors are concerned, the carbon-neutral feature of the construction sector is the most obvious, especially in the northeastern. (3) There are significant differences in the surplus of carbon ecological carrying capacity among provinces. Specifically, the regions with larger carbon ecological carrying capacity surplus are mainly distributed in the agricultural developed provinces, such as Heilongjiang, Henan, Jilin, Shandong, and so on (>10×108 t), while Beijing, Tianjin, Shanghai, Zhejiang, Fujian, and Guangdong are in deficit. In the future, when formulating relevant policies, we should comprehensively consider the characteristics of inter-provincial carbon transfer, reasonably allocate carbon emission quota, and ensure the smooth operation of the carbon emission trading market. 参考文献 相似文献 引证文献

The biological carbon pump and seaweeds

The interest of researchers in macrophytes in the seventies and eighties of the last century was associated with the need to obtain technologically important products, and by the end of the last century, technologies for cultivating several important species of algae were created and put into practice. Currently, the problem of climate change requires new approaches to find ways to transfer inorganic carbon from the atmosphere to the ocean floor. One of the ways to sequester inorganic carbon seems to be the creation of systems based on marine macrophytes. This should stimulate research into natural populations of macrophytes and the organization of cultivation methods according to a new optimization criterion, namely the optimal transfer of atmospheric carbon to the ocean floor.

Understanding and quantifying whole soil-profile organic carbon transfer using an environmental tracer

Context Quantifying soil organic carbon (SOC) depth distribution and its vertical transport is needed for both improved understanding of soil properties and behaviour as well as enhanced organic carbon sequestration. This is a global issue, that if better understood, could result in both more agriculturally productive soils as well as enhanced environmental outcomes. Aims Quantify whole soil-profile SOC and down-profile movement at a series of sites in south-east Australia. Methods Soil is sampled at regular intervals using cores and assessed for SOC and environmental tracer (137Cs) concentration. Key results Soils that have a high clay content (Vertosols) and crack (i.e. self mulching) have the highest SOC content. In high clay content soils, 137Cs is present at depths well below that at which it would be present by diffusive processes. Conclusions Surface soil, labelled with 137Cs is moving down the soil profile by advective processes to depths well below that possible by diffusive processes alone. Using local erosion rates and carbon input, it is estimated that less than 1% of SOC is delivered to the cracking soils by erosional processes and that the majority of SOC must be produced in situ. Implications Given that 137Cs is a relatively new environmental tracer (1945 onwards), this suggests that surface labelled soil is reaching depths of up to 80 cm at decadal time scales. The methods and findings here have global applicability and provide insights into potential enhancement of carbon sequestration in both cropping and grazing landscapes.

Characterisation of organic carbon distribution and turnover by stable carbon isotopes in major types of soils in China

Environmental context Soil carbon sequestration plays an important role in achieving the goal of carbon neutrality. We studied the characteristics of organic carbon distribution and sequestration by stable carbon isotopes in nine types of soils in China and found that macro-aggregates possessed more organic carbon with a low degree of decomposition, while the overall direction of organic carbon transfer between aggregates was from macro-aggregates through micro-aggregates to the grain-size fractions of chalky clay. These results provide a foundation for understanding soil carbon sequestration in China’s cultivated lands. Rationale Soil is the largest carbon reservoir of terrestrial ecosystems. Studying carbon turnover in cultivated soils is vital for China to achieve its carbon neutrality goal. Methodology In this research, we investigated the distribution characteristics of soil organic carbon and its turnover among aggregates in nine major soil types in China by 13C stable isotopes. Results Since the second national soil survey in China 1979, the surface soil organic carbon (SOC) content of cultivated lands in boggy soils, black soils and dark brown forest soils in northeastern China has decreased (129.06, 2.70 and 7.78 g kg−1, respectively) while increased in cinnamon soils, brown soils, red soils, latosols, paddy soils and chestnut soils (0.85–7.79 g kg−1). Overall, the SOC content was highest in 1–0.25 mm aggregates, lowest in 0.053–0.02 mm aggregates and higher in &lt;0.02 mm aggregates. The Δ13C value showed that the silt-clay size class fraction &gt; micro-aggregates &gt; macro-aggregates. Discussion The overall turnover direction of SOC among aggregates starts from macro-aggregates to micro-aggregates and ends with the silt-clay size class fraction. The result directly confirms both the ‘hierarchical development model’ and ‘embryonic development model’ of soil aggregate formation. The SOC flow direction and mobility potential between aggregates, as indicated by Δ13C values, suggest that cultivated soils are more susceptible to soil type than wasteland soils.

From Geospatial to Temporal Separation: A Review on Carbon Accounting Endogenizing Fixed Capital

A scientific and systematic approach that provides accurate carbon accounting is a fundamental prerequisite for responding to the climate crisis. The carbon accounting system has evolved from production-based accounting measuring territorial emissions to consumption-based accounting, gradually covering spatial and temporal separation. Its scientificity is thus enhanced. The temporal separation (between past production and current consumption) from fixed capital has become of recent interest, but a panoramic overview still rarely exists because of longstanding neglect. Combining quantitative analysis with a literature review, this study systematically analyzed the historical development and current state of carbon accounting, especially on studies endogenizing fixed capital, to locate hotspots and predict future trends. The current studies with fixed capital endogenization mainly use a flow matrix and augmented method to analyze the total and structure and the difference with traditional results, which are still in the initial rise stage; however, the process analysis and influence factor identification are insufficient. Therefore, this study proposes future avenues for analyzing the entire process of spatial and temporal carbon transfer based on a metabolic perspective and considering the initial input factors to identify the key drivers, which will provide new ideas and perspectives for policy formulation.

Renewable Energy for Balancing Carbon Emissions and Reducing Carbon Transfer under Global Value Chains: A Way Forward

Research on the relationship between a country’s renewable energy consumption and carbon emissions is of great significance for reducing carbon emissions embodied in international trade. There always exists a gap between production-based and consumption-based carbon emissions. Accordingly, this paper investigates the influence of renewable energy consumption on carbon emission balance, the ratio of production-based emissions to consumption-based emissions, in various countries using the ordinary least square (OLS) method and generalized method of moments (GMM) method. We found that a 1% increase in renewable energy consumption can decrease the carbon emission balance by 5.8%. Furthermore, renewable energy consumption can help narrow the gap between production-based and consumption-based carbon emissions in net emission exporters. In addition, renewable energy consumption can also weaken the negative impact of the global value chains (GVCs) division system on the carbon emission balance. The findings in this study fill the research gap by analyzing the heterogeneous impacts of renewable energy consumption on carbon emission balance embodied within a GVC division system in various countries and provide policy suggestions that renewable energy consumption should be encouraged in net emission exporters to reduce the carbon emission transfers.

Carbon and Nutrient Transfer via Above- and Below-Ground Litter in Forests

Plants periodically shed more than 90% of their biomass production as above- and below-ground litter, including leaves, twigs, flowers, logs, roots and other tissues [...]

Assessment and Adjustment of Export Embodied Carbon Emissions with Its Domestic Spillover Effects: Case Study of Liaoning Province, China

Export embodied carbon emissions (EECE) and their domestic spillover effects (DSE) are typical interregional carbon transfer phenomena. They have diversified impacts for different regions within a country, and result in the associated effect on the economy and environment. From 2007 to 2017, the EECE of China was mainly concentrated in five provinces, and EECE intensity mostly decreased. Liaoning Province had the largest EECE intensity and EECE growth from 2012 to 2017. Based on the multi-region input-output tables of China, we applied the Multi-region Input-output Model and constructed the Coupling Relationship Model for trade value and carbon emission, quantitatively assessed the EECE and its DSE for Liaoning Province, depicted the spatial-temporal evolution patterns, proposed sectoral adjustment countermeasures, and evaluated the adjustment effects. The research found that the EECE and its DSE of Liaoning Province was 32.08 MtCO2 and 5.43 MtCO2 in 2017. It was mainly concentrated in the metal smelting and rolling processing sector (MetalSmelt) and the petroleum processing, coking and nuclear fuel processing sectors (RefPetral). The spatial agglomeration effect was obvious, and Jilin Province was the largest DSE region. According to the Coupling Relationship Model of export trade value and export embodied carbon emissions, the sectors were divided into four types, and different adjustment countermeasures were proposed, such as encouragement, control, targeted promotion and targeted reduction. For the MetalSmelt and the RefPetral, if the export value reduced 100 million CNY, the EECE would be reduced by 21.57 ktCO2 and 23.35 ktCO2, respectively, and the DSE would be reduced by 1.59 ktCO2 and 1.65 ktCO2, respectively. The conclusions could provide a decision-making basis for the case area to formulate lower-cost and better-effective carbon reduction adjustment countermeasures. It could also provide reference and scientific support for the achievement of “Carbon Neutrality” and sustainable development in similar regions of the world with the rapid growth of EECE.

Hydrodynamic and geochemical controls on soil carbon mineralization upon entry into aquatic systems

Erosion is the most widespread form of soil degradation and an important pathway of carbon transfer from land into aquatic systems, with significant impact on water quality and carbon cycle. However, it remains debatable whether erosion induces a carbon source or sink, and the fate of eroded soil carbon in aquatic systems remains poorly constrained. Here, we collect 41 representative soils from seven erosion-influenced basins and conduct microcosm simulation experiments to examine the fate of soil carbon under three different scenarios. We showed that soil carbon mineralization was generally promoted (by up to 10 times) in water under turbulence relative to in soils, but suppressed under static conditions upon entering into aquatic systems. Moreover, the enhancement of mineralization in turbulent systems is primarily related to soil aggregate content, while suppression in static systems positively relates to macromolecule abundance, indicating that soil geochemistry affects the magnitude of hydrodynamic effects on carbon mineralization. Random forest model further predicts that erosion may induce significant carbon sources in basins dominated by turbulent waters and aggregate-rich soils. Our findings demonstrate hydrodynamic and geochemical controls on soil carbon mineralization upon delivery into aquatic systems, which is a non-negligible part of the boundless carbon cycle and must be considered when making region-specific conservation strategies to reduce CO2 emissions from inland waters.

The holoplanktonic mollusks (Pteropoda and Pterotrachoidea) in surface waters of the Campeche Canyon (southern Gulf of Mexico) during a winter storm (&amp;ldquo;Nortes&amp;rdquo;) season

The holoplanktonic mollusks (Mollusca, Pteropoda and Pterotrachoidea) are independent and key groups of organisms in any marine ecosystem due to the role they play in the carbon and energy transfer along the marine trophic webs. We document the species of holoplanktonic mollusks collected in the surface waters (10 m depth) during an oceanographic expedition in the Campeche Canyon, southern Gulf of Mexico, during the February 2011 winter storm (&amp;ldquo;Nortes&amp;rdquo;) season. Organisms were collected using a close/open/close net system. Eighteen species belonging to 12 genera and nine families of pteropods were identified. Three species of Pterotrachoidea were identified. Limacina trochiformis (d&amp;rsquo;Orbigny, 1835), Heliconoides inflatus (d&amp;rsquo;Orbigny, 1835), and Creseis conica (Eschscholtz, 1829) were the species with highest density values (600.3, 678.5, and 746.8 ind &amp;middot; 100 m&amp;minus;3, respectively). The results presented here contribute to the knowledge of this group of organisms in oceanic waters of the southern Gulf of Mexico, especially during a time of year where observations are scarce.

Exploration of CO2 emission reduction pathways: identification of influencing factors of CO2 emission and CO2 emission reduction potential of power industry.

The online version contains supplementary material available at 10.1007/s10098-022-02456-1.

Ecosystem carbon use efficiency in ecologically vulnerable areas in China: Variation and influencing factors.

Ecologically vulnerable areas (EVAs) are regions with ecosystems that are fragile and vulnerable to degradation under external disturbances, e.g., environmental changes and human activities. A comprehensive understanding of the climate change characteristics of EVAs in China is of great guiding significance for ecological protection and economic development. The ecosystem carbon use efficiency (CUEe) can be defined as the ratio of the net ecosystem productivity (NEP) to gross primary productivity (GPP), one of the most important ecological indicators of ecosystems, representing the capacity for carbon transfer from the atmosphere to a potential ecosystem carbon sink. Understanding the variation in the CUEe and its controlling factors is paramount for regional carbon budget evaluation. Although many CUEe studies have been performed, the spatial variation characteristics and influencing factors of the CUEe are still unclear, especially in EVAs in China. In this study, we synthesized 55 field measurements (3 forestland sites, 37 grassland sites, 6 cropland sites, 9 wetland sites) of the CUEe to examine its variation and influencing factors in EVAs in China. The results showed that the CUEe in EVAs in China ranged from -0.39 to 0.67 with a mean value of 0.20. There were no significant differences in the CUEe among different vegetation types, but there were significant differences in CUEe among the different EVAs (agro-pastoral ecotones < Tibetan Plateau < arid and semiarid areas < Loess Plateau). The CUEe first decreased and then increased with increasing mean annual temperature (MAT), soil pH and soil organic carbon (SOC) and decreased with increasing mean annual precipitation (MAP). The most important factors affecting the CUEe were biotic factors (NEP, GPP, and leaf area index (LAI)). Biotic factors directly affected the CUEe, while climate (MAT and MAP) and soil factors (soil pH and SOC) exerted indirect effects. The results illustrated the comprehensive effect of environmental factors and ecosystem attributes on CUEe variation, which is of great value for the evaluation of regional ecosystem functions.

Two-stage distributionally robust optimization model of integrated energy system group considering energy sharing and carbon transfer

Due to the small scale and few functions of the single integrated energy system, the absorption capacity of wind turbine and photovoltaic is limited, the ability to cope with uncertainties is weak, and the space for optimal allocation of resources is limited. To solve the coordination problem of robustness, economy, environmental protection and efficiency, this paper forms an integrated energy system group (IESG) by means of energy sharing and carbon transfer, and innovatively proposes a two-stage distributionally robust optimization model (TSDRO) based on kernel density estimation (KDE) and Wasserstein metric. Firstly, the structure of IESG with carbon capture, utilization, and storage-power-to-gas (CCUS-P2G) system is introduced. Then, the nonparametric KDE method is applied to fit the probability density functions of the forecast power error of wind turbine and photovoltaic. Wasserstein metric is used to characterize the fuzzy uncertainty set of distributions. The cumulative distribution function of KDE is taken as the center, and the obtained distance is taken as the radius to form the Wasserstein ball of probability distribution. Based on affinely adjustable policy, a correlation model of real-time variables with respect to day-ahead variables is established. Finally, according to the dual theory and convex optimization theory, the TSDRO model is reformulated into a solvable model. The simulation results show that: (1) energy sharing and carbon transfer can improve the ability of IESG to cope with uncertainty and expand the boundary of resource optimal allocation, and the minimum expected operating cost under the worst distribution is $ 40,259.94. (2) CCUS-P2G system strengthens the synergistic relationship between electricity and carbon and reduces the carbon emission of the system by 128.2 t. (3) After testing, the results obtained by nonparametric KDE are closer to the true distribution and more objective. (4) The TSDRO model is data-driven and has the advantages of high solving efficiency and low decision-making conservatism. The solution time of the TSDRO model is 73.03 % less than that of the stochastic optimization model, and the operation cost is 1.69 % less than that of the robust optimization model, which achieves the balance of economy, robustness and environmental protection of IESG.

Long-term low-friction of Ti-overcoated and-doped DLCs: Robustly developed carbonous transfer layer with titanium

Diamond-like carbon (DLC) has been under the research spotlight as an exceptional solid lubricant. Its friction performance is depending on a well-developed transfer layer upon its counterparts. Nowadays, iron-and brass-based metals have been utilized as the counterpart against DLC, however, it is reported their friction behaviors are somewhat inferior compared to titanium alloys. In this study, we tried to improve their friction behaviors and modified the contact interface from Fe/C to C/C by Ti addition in DLC. It was revealed that Ti, which has good adhesion for Fe and C, promoted the development of carbon transfer on Fe-based counterpart. Furthermore, Ti built-up a thick carbonous transfer layer and make better the friction performance of DLC sliding against Fe.

A major orbito-hyetal event at the middle-to-late Oxfordian transition (Late Jurassic)

Arido-eustasy is a model that explains palaeoenvironmental change by linking the covariation of the carbon isotope record and the eustatic sea level to orbitally modulated hydroclimatic intensity. Orbitally forced wet climate modes periodically accelerate the water cycle in the biosphere, modulating the balance between terrestrial fresh-water reservoirs and the eustatic sea level and perturbating the carbon cycle through catastrophic weathering of terrestrial carbon reservoirs, resulting in excessive transfer of carbon into the oceans. These intervals of extreme hydroclimatic intensity and weathering, or Orbito-Hyetal Events (OHEs), are hypothesised to be responsible for major palaeoenvironmental crises such as oceanic anoxic events and biotic extinction events. Here, I consider the available data and show evidence for the occurrence of a strong and short-term OHE at the end of the middle Oxfordian. The event probably lasted ∼40 kyr and was bracketed by characteristic arido-eustatic traits, including a prominent sea level fall (the OX5), a contemporaneous extreme (>2‰) negative excursion in the marine carbonate and terrestrial organic-carbon isotope records, and regional occurrences of anoxic environments with organic-rich deposits. Important prolific source-rock reservoirs, such as the Smackover, Hanifa, and Khodjaipak Formations in the Gulf of Mexico, Arabian Gulf, and Uzbekistan, respectively, seem to have been created during this end-middle Oxfordian OHE.