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The atmospheric carbon dioxide (CO2) concentration has been increasing rapidly since the Industrial Revolution, which has led to unequivocal global warming and crucial environmental change. It is extremely important to investigate the interactions among atmospheric CO2, the physical climate system, and the carbon cycle of the underlying surface for a better understanding of the Earth system. Earth system models are widely used to investigate these interactions via coupled carbon-climate simulations. The Chinese Academy of Sciences Earth System Model version 2 (CAS-ESM2.0) has successfully fixed a two-way coupling of atmospheric CO2 with the climate and carbon cycle on land and in the ocean. Using CAS-ESM2.0, we conducted a coupled carbon-climate simulation by following the CMIP6 proposal of a historical emissions-driven experiment. This paper examines the modeled CO2 by comparison with observed CO2 at the sites of Mauna Loa and Barrow, and the Greenhouse Gases Observing Satellite (GOSAT) CO2 product. The results showed that CAS-ESM2.0 agrees very well with observations in reproducing the increasing trend of annual CO2 during the period 1850–2014, and in capturing the seasonal cycle of CO2 at the two baseline sites, as well as over northern high latitudes. These agreements illustrate a good ability of CAS-ESM2.0 in simulating carbon-climate interactions, even though uncertainties remain in the processes involved. This paper reports an important stage of the development of CAS-ESM with the coupling of carbon and climate, which will provide significant scientific support for climate research and China's goal of carbon neutrality. [ABSTRACT FROM AUTHOR]

Atmospheric carbon dioxide emanating from activities associated with the construction of buildings in the UK contributes approximately 16% of the uk's total emissions and will need to be reduced significantly to meet international agreements. Against this scenario, this paper presents a novel perspective for carbon accounting and trading that proposes the use of a platform for the uk construction industry as a possible solution. This suggestion assumes that taxation should be synchronised with phases of the entire life cycle of the building and that tax credits (or deficits) should remain an asset of the building itself. In this regard, a strategy is in place in the uk, but with gaps in how it will be implemented. To resolve these gaps, firstly, this paper explores and integrates three socio-technical components (i.e., carbon accounting, trading, and certification) that form an essential set of tools required for the management of taxes directed at property developers and construction companies. Then, it points out the need for a suite of computer-based systems to facilitate the recording of emissions information, the purchase of carbon offsets, and a way to access specialist financial services. As a result, a trading platform is conceptualised that makes use of blockchain technology as a foundation for future research. [ABSTRACT FROM AUTHOR]

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Increasing terrestrial ecosystem carbon sink is an effective way to mitigate the rise of atmospheric carbon dioxide (CO2) concentration and achieve the goal of "carbon neutrality". Mycorrhizal fungi are beneficial microorganisms that can form symbiotic relationships with 90% of plants in terrestrial ecosystems, and the symbiont contributes significantly to soil and plant carbon sink. In the review, we take arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF), which are the most extensively studied currently, as the narrative objects, and discuss the carbon sink enhancement potential of mycorrhizal fungi from the following four aspects. The first, mycorrhizal fungi indirectly increase the plant carbon sink by promoting photosynthesis and increasing biomass in the host plant, and this advantage can be maintained even under stressful conditions. The second, the process of carbon source transportation between AMF-plant symbionts and EMF-plant symbionts is described in this paper. The third, review describes that mycorrhizal fungi contribute to soil carbon sink by increasing carbon input as well as decreasing carbon output. The fourth, we point out the shortcomings of the current study and provide a prospect for future research, with the aim to provide theoretical support for increasing terrestrial carbon sink. [ABSTRACT FROM AUTHOR]

The atmospheric concentration of CO2 is steadily increasing and causing climate change. To achieve the Paris 1.5 or 2°C target, negative emission technologies must be deployed in addition to reducing carbon emissions. The ocean is a large carbon sink but the potential of marine primary producers to contribute to carbon neutrality remains unclear.Here we review the alterations to carbon capture and sequestration of marine primary producers (including traditional 'blue carbon' plants, microalgae and macroalgae) in the Anthropocene, and, for the first time, assess and compare the potential of various marine primary producers to carbon neutrality and climate change mitigation via biogeoengineering approaches.The contributions of marine primary producers to carbon sequestration have been decreasing in the Anthropocene due to the decrease in biomass driven by direct anthropogenic activities and climate change. The potential of blue carbon plants (mangroves, saltmarshes and seagrasses) is limited by the available areas for their revegetation. Microalgae appear to have a large potential due to their ubiquity but how to enhance their carbon sequestration efficiency is very complex and uncertain. On the other hand, macroalgae can play an essential role in mitigating climate change through extensive offshore cultivation due to higher carbon sequestration capacity and substantial available areas. This approach seems both technically and economically feasible due to the development of offshore aquaculture and a well‐established market for macroalgal products.Synthesis and applications. This paper provides new insights and suggests promising directions for utilizing marine primary producers to achieve the Paris temperature target. We propose that macroalgae cultivation can play an essential role in attaining carbon neutrality and climate change mitigation, although its ecological impacts need to be assessed further. [ABSTRACT FROM AUTHOR]

The continued rise in anthropogenic carbon dioxide (CO2) emissions and increase in atmospheric CO2 concentration has led to calls from experts, including the Intergovernmental Panel on Climate Change that has estimated that global warming needs to be limited to 1.5 °C above preindustrial levels to avoid the worst effects of climate change, and that carbon neutrality would need to be achieved globally by 2050 to meet this target. Achieving carbon neutrality by mid‐century will rely on successful implementation and widespread adoption of technologies for reducing emissions from large point sources of CO2, direct CO2 capture from the air, as well as storage and utilization technologies that would convert CO2 to a form that would ensure safety and permanency of storage. In this paper, engineering solutions for CO2 capture, utilization, and storage are reviewed with a focus on technology readiness level, and cost. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Human-induced climate change has become a prominent political issue, at both national and international levels, leading to the search for regulatory 'solutions'. Emissions trading has risen in popularity to become the most broadly favoured government strategy. Carbon permits have then quickly been developed as a serious financial instrument in markets turning over billions of dollars a year. In this article, I show how the reality of permit market operation is far removed from the assumptions of economic theory and the promise of saving resources by efficiently allocating emission reductions. The pervasiveness of Greenhouse Gas emissions, strong uncertainty and complexity combine to prevent economists from substantiating their theoretical claims of cost-effectiveness. Corporate power is shown to be a major force affecting emissions market operation and design. The potential for manipulation to achieve financial gain, while showing little regard for environmental or social consequences, is evident as markets have extended internationally and via trading offsets. At the individual level, there is the potential for emissions trading to have undesirable ethical and psychological impacts and to crowd out voluntary actions. I conclude that the focus on such markets is creating a distraction from the need for changing human behaviour, institutions and infrastructure. [ABSTRACT FROM AUTHOR]

Forest ecosystems store large amounts of carbon and can be important sources, or sinks, of the atmospheric carbon dioxide that is contributing to global warming. Understanding the carbon storage potential of different forests and their response to management and disturbance events are fundamental to developing policies and scenarios to partially offset greenhouse gas emissions. Projections of live tree carbon accumulation are handled differently in different models, with inconsistent results. We developed growth-and-yield style models to predict stand-level live tree carbon density as a function of stand age in all vegetation types of the coastal Pacific region, US (California, Oregon, and Washington), from 7,523 national forest inventory plots. We incorporated site productivity and stockability within the Chapman-Richards equation and tested whether intensively managed private forests behaved differently from less managed public forests. We found that the best models incorporated stockability in the equation term controlling stand carrying capacity, and site productivity in the equation terms controlling the growth rate and shape of the curve. RMSEs ranged from 10 to 137 Mg C/ha for different vegetation types. There was not a significant effect of ownership over the standard industrial rotation length (~50 yrs) for the productive Douglas-fir/western hemlock zone, indicating that differences in stockability and productivity captured much of the variation attributed to management intensity. Our models suggest that doubling the rotation length on these intensively managed lands from 35 to 70 years would result in 2.35 times more live tree carbon stored on the landscape. These findings are at odds with some studies that have projected higher carbon densities with stand age for the same vegetation types, and have not found an increase in yields (on an annual basis) with longer rotations. We suspect that differences are primarily due to the application of yield curves developed from fully-stocked, undisturbed, single-species, "normal" stands without accounting for the substantial proportion of forests that don't meet those assumptions. The carbon accumulation curves developed here can be applied directly in growth-and-yield style projection models, and used to validate the predictions of ecophysiological, cohort, or single-tree style models being used to project carbon futures for forests in the region. Our approach may prove useful for developing robust models in other forest types. [ABSTRACT FROM AUTHOR]

Building multi-energy complementary integrated energy systems (IES) is a crucial way to achieve the goal of carbon peaking and carbon neutrality. However, uncertainties at both the source and load ends pose particular challenges to the optimal design and operation of the system. This paper proposes a multi-stage stochastic planning model considering CO2, NOx, and SO2 emissions and multiple uncertainties. The k-means algorithm was used to obtain typical scenarios and typical parameters of the reference building. The uncertain scenarios with probability distributions are generated by Latin hypercubic sampling and backward curtailment method. Then, a novel multi-objective sand cat swarm optimization (MOSCSO) algorithm is proposed for solving the upper-layer design model. The lower layer scheduling model is constructed as a mixed-integer linear programming model, and the solver is invoked for optimization. A case study validates the proposed model. Compared to different operating strategies, the two-layer optimization model can achieve a maximum of 13.54 %, 12.38 %, and 21.73 % improvement in economic, energy, and environmental. Compared to electricity price uncertainty, the sensitivity analysis suggests that gas price uncertainty negatively impacts the system. In addition, the two-layer optimization model under a single uncertainty provides the best economic, energy, and environmental compared to the operational strategies. • A multi-stage two-layer optimization model considering multiple uncertainties is proposed. • A novel MOSCSO algorithm is proposed. • The system performance considering multiple uncertainties are analyzed under different operating strategies. • Thesystem performance under two-layer optimization model considering multiple uncertainties are analyzed. • The sensitivity analyses are performed for different single uncertainty factors. [ABSTRACT FROM AUTHOR]

The long-term goal of containing average warming below the 2 °C limit requires deep cuts in emissions from all sectors. The fast growing global aviation industry has committed to reduce carbon emissions. Carbon offsetting is an integral element of the sector's strategy. Already, airlines offer voluntary carbon offsetting to those customers who wish to mitigate the impact of their travel. To ensure carbon offsetting can make a meaningful and credible contribution, this paper first discusses the science behind ‘carbon offsetting’, followed by the associated policy perspective. Then, against the context of different aviation emissions pathways, the paper provides empirical evidence of current airline practices in relation to offsetting mechanisms and communication. Building on these insights, the challenges of reducing aviation emissions and using carbon credits to compensate for ongoing growth are discussed. The paper concludes by proposing five principles of best practice for carbon offsetting that airlines can use as a basis to develop credible emissions strategies, and that could inform the sectoral framework currently being developed by leading aviation organisations. [ABSTRACT FROM AUTHOR]

Forests play an essential role in climate change mitigation by absorbing carbon dioxide from the atmosphere and storing carbon in biomass. Carbon sequestration can be increased by the extension of rotation cycles in existing plantation forests. This study examines the cost‐effectiveness of the remuneration scheme employed by Verified Carbon Standard (VCS), a commonly used carbon accounting method based on the average amount of carbon stored in the forest. We compare the net present value of carbon remuneration under VCS with that of a scheme that remunerates actual carbon storage in each year which we call "current carbon accounting." We use data for an Acacia mangium plantation in Indonesia where the forestry sector is expected to contribute more than half of the reductions of carbon emissions according to Indonesia's Nationally Determined Contribution (NDC) under the Paris Agreement. For our baseline scenario, we find, first, that the payments needed to incentivise additional carbon storage under VCS are considerably higher than under current carbon accounting. Second, the inefficiency is more pronounced at lower discount rates. Third, recent prices reported for VCS forest credits are not sufficient to incentivise forest managers to lengthen the forest rotation in Indonesian plantation forests. Recommendations for Resource Managers: Older forests store more carbon. Using a multiple rotations model our study determines how carbon payments incentivise forest managers to lengthen the forest rotation and, hence, to sequester and store more carbon. Forest managers should consider carbon remuneration options in their forest management decisions, in particular when choosing the length of the rotation period.Optimal forest management is impacted by the design of the remuneration scheme. It matters in particular whether carbon sequestration or carbon storage is paid for.Fund managers can incentivise larger amounts of carbon storage through careful design of the carbon remuneration scheme. [ABSTRACT FROM AUTHOR]

Biomass pyrolysis is a promising method to produce renewable energy, which can contribute to the realization of carbon neutrality. However, high oxygen content and complex composition hinder the utilization of bio-oil produced by biomass pyrolysis. A new technology, two-step fast pyrolysis of torrefied biomass derived from corncobs and waste cooking oil under CO 2 atmosphere, was studied to produce hydrocarbons-rich bio-oil. Results showed that two-step pyrolysis was beneficial to the initial separation of hydrocarbons and oxygen-laden compounds. And the synergy between the torrefied corncobs and waste cooking oil occurred primarily in the second step of the two-step pyrolysis. Application of CO 2 in the first step significantly decreased the total peak area of condensable organic compounds, but increased the relative content of hydrocarbons. No matter what atmosphere was used in the first step, the relative content of hydrocarbons during the application of CO 2 in the second step was lower. Using a CO 2 atmosphere in the first step gave better results, while using N 2 in the second step tended to maximize the hydrocarbons content. Combined with CO 2 -assisted pyrolysis and stepwise pyrolysis, this paper provides a new idea for the thermal conversion of corncobs and waste cooking oil, to produce hydrocarbons. [Display omitted] • Two-step pyrolysis is conducive to hydrocarbon and oxygen-laden compound separation. • Synergy between torrefied corncobs and waste cooking oil occurred in second step. • CO 2 is suitable for the application in first step. • Relative content of hydrocarbons decreased with the use of CO 2 in second stage. • Two-step pyrolysis coupled with CO 2 atmosphere is better for hydrocarbon production. [ABSTRACT FROM AUTHOR]

Thermochemical conversion of fossil resources into fuels, chemicals, and materials has rapidly increased atmospheric CO2 levels, hindering global efforts toward achieving carbon neutrality. With the increasing push for sustainability, utilizing electrochemical technology to transform CO2 or biomass into value‐added chemicals and to close the carbon cycle with sustainable energy sources represents a promising strategy. Expanding the scope of electrosynthesis technology is a prerequisite for the electrification of chemical manufacturing. To this end, constructing the C─N bond is considered a priority. However, a systematic review of electrocatalytic processes toward building C─N bonds using CO2 and biomass as carbon sources is not available. Accordingly, this review highlights the research progress in the electrosynthesis of organic nitrogen compounds from CO2 and biomass by C─N coupling reactions in view of catalytic materials, focusing on the enlightenment of traditional catalysis on C─N coupling and the understanding of the basis of electrochemical C─N coupling. The possibility of C─N bond in electrocatalysis is also examined from the standpoints of activation of substrates, coupling site, mechanism, and inhibition of hydrogen evolution reaction (HER). Finally, the challenges and prospects of electrocatalytic C─N coupling reactions with improved efficiency and selectivity for future development are discussed. [ABSTRACT FROM AUTHOR]

Boron isotopes in planktonic foraminifera are a widely used proxy to determine ancient surface seawater pH and by extension atmospheric CO 2 concentration and climate forcing on geological timescales. Yet, to reconstruct absolute values for pH and CO 2 , we require a δ11 B foram-borate to pH calibration and independent determinations of ocean temperature, salinity, a second carbonate parameter, and the boron isotope composition of seawater. Although δ11 B-derived records of atmospheric CO 2 have been shown to perform well against ice-core-based CO 2 reconstructions, these tests have been performed at only a few locations and with limited temporal resolution. Here we present two highly resolved CO 2 records for the late Pleistocene from Ocean Drilling Program (ODP) Sites 999 and 871. Our δ11 B-derived CO 2 record shows a very good agreement with the ice core CO 2 record with an average offset of 13±46 (2σ) and an RMSE of 26 ppm, with minor short-lived overestimations of CO 2 (of up to ∼50 ppm) occurring during some glacial onsets. We explore potential drivers of this disagreement and conclude that partial dissolution of foraminifera has a minimal effect on the CO 2 offset. We also observe that the general agreement between δ11 B-derived and ice core CO 2 is improved by optimising the δ11 B foram-borate calibration. Despite these minor issues, a strong linear relationship between relative change in climate forcing from CO 2 (from ice core data) and pH change (from δ11 B) exists over the late Pleistocene, confirming that pH change is a robust proxy of climate forcing over relatively short (<1 million year) intervals. Overall, these findings demonstrate that the boron isotope proxy is a reliable indicator of CO 2 beyond the reach of the ice cores and can help improve determinations of climate sensitivity for ancient time intervals. [ABSTRACT FROM AUTHOR]

Radiocarbon is a tracer that provides unique insights into the ocean's ability to sequester CO 2 from the atmosphere. While spatial patterns of radiocarbon in the ocean interior can indicate the vectors and timescales for carbon transport through the ocean, estimates of the global average ocean–atmosphere radiocarbon age offset (B-Atm) place constraints on the closure of the global carbon cycle. Here, we apply a Bayesian interpolation method to compiled B-Atm data to generate global interpolated fields and mean ocean B-Atm estimates for a suite of time slices across the last deglaciation. The compiled data and interpolations confirm a stepwise and spatially heterogeneous "rejuvenation" of the ocean, suggesting that carbon was released to the atmosphere through two swings of a "ventilation seesaw" operating between the North Atlantic and both the Southern Ocean and the North Pacific. Sensitivity tests using the Bern3D model of intermediate complexity demonstrate that a portion of the reconstructed deglacial B-Atm changes may reflect "phase-attenuation" biases that are unrelated to ocean ventilation and that arise from independent atmospheric radiocarbon dynamics instead. A deglacial minimum in B-Atm offsets during the Bølling–Allerød could partly reflect such a bias. However, the sensitivity tests further demonstrate that when correcting for such biases, ocean "ventilation" could still account for at least one-third of deglacial atmospheric CO 2 rise. This contribution to CO 2 rise appears to have continued through the Younger Dryas, though much of the impact was likely achieved by the end of the Bølling–Allerød, indicating a key role for marine carbon cycle adjustment early in the deglacial process. Our global average B-Atm estimates place further new constraints on the long-standing mystery of global radiocarbon budget closure across the last deglaciation and suggest that glacial radiocarbon production levels are likely underestimated on average by existing reconstructions. [ABSTRACT FROM AUTHOR]

This paper proposes a new methodology for carbon price forecasting. It posits a finite distributed lag (FDL) model and then applies a GA-ridge algorithm to determine a set of proper predictors with coefficient estimates. An empirical study was conducted in the European Union Greenhouse Gas Emissions Trading market, revealing that our methodology not only yields good forecasting results but also provides some interesting analysis on the carbon price market. It turns out that the combination of the FDL model and GA-ridge algorithm is desirable for forecasting and analyzing the complicated carbon price market because of its capability of selecting proper predictors from a class of predictors of itself. [ABSTRACT FROM AUTHOR]

The small but stubbornly unyielding possibility of a very large long-term response of global temperature to increases in atmospheric carbon dioxide can be termed the fat tail of high climate sensitivity. Recent economic analyses suggest that the fat tail should dominate a rational policy strategy if the damages associated with such high temperatures are large enough. The conclusions of such analyses, however, depend on how economic growth, temperature changes, and climate damages unfold and interact over time. In this paper we focus on the role of two robust physical properties of the climate system: the enormous thermal inertia of the ocean, and the long timescales associated with high climate sensitivity. Economic models that include a climate component, and particularly those that focus on the tails of the probability distributions, should properly represent the physics of this slow response to high climate sensitivity, including the correlated uncertainty between present forcing and climate sensitivity, and the global energetics of the present climate state. If climate sensitivity in fact proves to be high, these considerations prevent the high temperatures in the fat tail from being reached for many centuries. A failure to include these factors risks distorting the resulting economic analyses. For example, we conclude that fat-tail considerations will not strongly influence economic analyses when these analyses follow the common-albeit controversial-practices of assigning large damages only to outcomes with very high temperature changes and of assuming a significant baseline level of economic growth. [ABSTRACT FROM AUTHOR]

In a globalised world, the transfer of carbon between regions, either physically or embodied in production, represents a substantial fraction of global carbon emissions. The resulting emission transfers are important for balancing regional carbon budgets and for understanding the drivers of emissions. In this paper we synthesise current understanding in two parts: (1) CO2 emissions embodied in goods and services that are produced in one country but consumed in others, and (2) carbon physically present in fossil fuels, petroleum-derived products, harvested wood products, crops, and livestock products. We describe the key differences between studies and provide a consistent set of estimates using the same definitions, modelling framework, and consistent data. We find the largest trade flows of carbon in international trade in 2004 were fossil fuels (2673MtC, 37% of global emissions), CO2 embodied in traded goods and services (1661MtC, 22%of global emissions), crops (522MtC, 31% of total harvested crop carbon), petroleum-based products (183MtC, 50% of their total production), harvested wood products (149MtC, 40% of total roundwood extraction), and livestock products (28MtC, 22% of total livestock carbon).We find that for embodied CO2 emissions, estimates from independent studies are robust, and that differences between individual studies are not a reflection of the uncertainty in consumption-based estimates, but rather these differences result from the use of different production-based emissions input data and different definitions for allocating emissions to international trade. After adjusting for these issues, results across independent studies converge to give less uncertainty than previously assumed. For physical carbon flows there are relatively few studies to be synthesised, but differences between existing studies are due to the method of allocating to international trade, with some studies using "apparent consumption" as opposed to "final consumption". While results across studies are sufficiently robust to be used in further applications, more research is needed to understand differences and to harmonise definitions for particular applications. [ABSTRACT FROM AUTHOR]

Increasing soil organic carbon (SOC) stocks in agricultural soils removes carbon dioxide from the atmosphere and contributes towards achieving carbon neutrality. For farmers, higher SOC levels have multiple benefits, including increased soil fertility and resilience against drought-related yield losses. However, increasing SOC levels requires agricultural management changes that are associated with costs. Private soil carbon certificates could compensate for these costs. In these schemes, farmers register their fields with commercial certificate providers who certify SOC increases. Certificates are then sold as voluntary emission offsets on the carbon market. In this paper, we assess the suitability of these certificates as an instrument for climate change mitigation. From a soils' perspective, we address processes of SOC enrichment, their potentials and limits, and options for cost-effective measurement and monitoring. From a farmers' perspective, we assess management options likely to increase SOC, and discuss their synergies and trade-offs with economic, environmental and social targets. From a governance perspective, we address requirements to guarantee additionality and permanence while preventing leakage effects. Furthermore, we address questions of legitimacy and accountability. While increasing SOC is a cornerstone for more sustainable cropping systems, private carbon certificates fall short of expectations for climate change mitigation as permanence of SOC sequestration cannot be guaranteed. Governance challenges include lack of long-term monitoring, problems to ensure additionality, problems to safeguard against leakage effects, and lack of long-term accountability if stored SOC is re-emitted. We conclude that soil-based private carbon certificates are unlikely to deliver the emission offset attributed to them and that their benefit for climate change mitigation is uncertain. Additional research is needed to develop standards for SOC change metrics and monitoring, and to better understand the impact of short term, non-permanent carbon removals on peaks in atmospheric greenhouse gas concentrations and on the probability of exceeding climatic tipping points. Overview of the challenges associated with using soil carbon certificates as privately traded, voluntary emission offsets. [Display omitted] • Soil-based carbon certificates are sold as voluntary emission offsets. • Private certification schemes provide financial incentives for carbon farming. • However, they are not a suitable tool for climate change mitigation. • Permanence, additionality and monitoring are not ensured; leakage effects may occur. • Accountability in case of re-emissions of stored carbon is low. [ABSTRACT FROM AUTHOR]

As an important type of terrestrial carbon sink, forests play a critical role in offsetting anthropogenic fossil fuel CO2 emissions which should help nations to achieve carbon neutrality goals worldwide. According to National Forest Inventory (NFI), China has experienced substantial increases in forest cover by benefiting from national afforestation projects initiated in the l980s. However, none of the current land use and land cover (LULC) data sets can reproduce the long‐term changes of forest cover derived from NFI in China. Here, by combining NFI and 20 LULC data sets, we developed a new method of reconstructing historical forest cover in China from 1980 to 2015 at 5‐year intervals. The new forest cover data set can accurately reproduce the historical changes of forest cover in China during this period. Validated against 3851 field survey samples covering the study period of 1985–2015, the data sets show high accuracy with overall accuracy varying from 76.9% to 99.4%. Accurate long‐term forest cover maps have great potential for use in estimating terrestrial carbon, tracking forest management, and other scientific research studies. Plain Language Summary: Planting trees can absorb carbon dioxide from the atmosphere and mitigate global warming. Benefiting from the national afforestation projects initiated in the early 1980s, forests in China have grown significantly. However, these land cover maps, based on remote sensing satellite observations, do little to reproduce this remarkable greening change. Therefore, we produced a new forest map data set for China from 1980 to 2015 by combining the statistical forest area and up to 20 different remotely sensed land cover maps at 5‐year intervals. The new forest map data set has a high validation accuracy and reproduces the greening process in China well. Accurate long‐term forest maps are essential to better understanding the potential of trees to mitigate climate change through CO2 uptake. Key Points: We reconstructed long‐term Chinese forest cover maps by combining national forest inventory and 20 land use and land cover data setsThe reconstructed forest cover maps reproduced well Chinese forest change consistent with national forest inventoryReconstructed forest maps provide the distribution of various forest types in China [ABSTRACT FROM AUTHOR]

This perspective article aims to identify key research priorities to make the waste-to-energy sector compatible with the societal goals of circularity and carbon neutrality. These priorities range from fundamental research to process engineering innovations and socio-economic challenges. Three focus areas are highlighted: (i) the optimization of flue gas cleaning processes to minimize gaseous emissions and cross-media, (ii) the expansion of process control intelligence to meet targets for both material recovery and energy recovery, and (iii) climate neutrality, with the potential for negative emissions via the removal of atmospheric carbon dioxide across the full cycle of the waste resource. For each area, recent research trends and key aspects that are yet to be addressed are discussed. [ABSTRACT FROM AUTHOR]

To keep temperature rise well below 2 °C, production systems should be synthesised in a way that are regenerative, climate-resilient, and equitable, and to maintain biodiversity to preserve life and meet future human needs with the integrity of nature. In line with this approach, this paper presents a stepwise transition to a regenerative energy system in the EU by 2050, with the aim of going beyond carbon neutrality and achieving annual net negative emissions. A mixed-integer linear programming model is developed with the goal of maximising the Sustainability Net Present Value while achieving a balanced solution between all the three basic sustainability pillars. In order to obtain a regenerative system design, the annual self-sequestration of CO 2 by the Earth was evaluated based on the amount of CO 2 released into the atmosphere and the change in atmospheric CO 2 concentration. The impact of different CO 2 emission reduction scenarios on the atmospheric CO 2 concentration until 2050 was evaluated. The results show that carbon neutrality at the global level could be achieved by 2050 with a 1.63% annual reduction in anthropogenic CO 2 emissions. Moreover, the results indicate that if carbon emission neutrality is achieved at the global level in 2050, it could be achieved in the EU as early as 2039, given the Earth's self-sequestration capacity. To go beyond carbon emissions neutrality at the EU level, electricity demand is expected to nearly double, particularly due to the electrification of road transport, the use of heat pumps for heating residential and the tertiary sectors, 6G and IoT widespread out etc. • A critical review of sustainable heat production technologies. • A MILP model to achieve carbon emissions neutrality or negative net emissions in the EU by 2050. • Cross-sectoral synthesis of regenerative energy systems – beyond sustainability. • Assessment and prediction of Earth's self-sequestration in the synthesis of regenerative energy systems. [ABSTRACT FROM AUTHOR]

Two of the most important CO2 sequestration processes on Earth are plant photosynthesis and rock chemical dissolution. Photosynthesis is undoubtedly the most important biochemical reaction and carbon sink processes on Earth. Karst geological action does not produce net carbon sinks. Photosynthesis and karstification in nature are coupled. Karstification–photosynthesis coupling can stabilize and increase the capacity of karstic and photosynthetic carbon sinks. Bidirectional isotope tracer culture technology can quantify the utilization of different inorganic carbon sources by plants. Bicarbonate utilization by plants is a driver of karstification–photosynthesis coupling, which depends on plant species and the environment. Carbonic anhydrase, as a pivot of karstification–photosynthesis coupling, can promote inorganic carbon assimilation in plants and the dissolution of carbonate rocks. Karst-adaptable plants can efficiently promote root-derived bicarbonate and atmospheric carbon dioxide use by plants, finally achieving the conjugate promotion of karstic carbon sinks and photosynthetic carbon sinks. Strengthening karstification–photosynthesis coupling and developing karst-adaptable plants will greatly improve the capacity of carbon sinks in karst ecosystems and better serve the "Carbon peak and Carbon neutralization" goals of China. [ABSTRACT FROM AUTHOR]

The prioritized purpose of this dissertation is to put forward a scientific and plausible interval of carbon price benchmark on the unified carbon trading market, of which will be scheduled to be established in the year of 2016. A model named EMD–GARCH that integrated Empirical Mode Decomposition (EMD) with Generalized Autoregressive Conditionally Heteroskedastic (GARCH) together is presented here in order to forecast the carbon price of the five pilots (Shenzhen, Shanghai, Beijing, Guangdong, and Tianjin) in 2016 so as to provide exogenous data for later analysis. For further study, a recursive dynamic Computable General Equilibrium (CGE) model will be structured to explore the impacts on China’s macroeconomics, environmental quality, and energy demand respectively under 8 different simulation scenarios, which are being designed in terms of the aforementioned calculated carbon price outcome. The simulation results illustrate that the unified carbon price policy will exert a comprehensive effect on China in various perspectives that we discussed in this paper. Moreover, regarding the carbon price scenarios, the price level by itself generates a different degree of impacts in improving the environmental quality, decreasing the energy demand, and increasing the macroeconomic growth. Consequently, based on the analysis of those three approaches mix in this study, we suggest the alternative interval of carbon price benchmark in the national unified carbon trading market with a lower bound of 30 yuan/tCO 2 to an upper bound of 50 yuan/tCO 2 . [ABSTRACT FROM AUTHOR]

Development of carbon polygons for monitoring the emission and deposition of carbon compounds in terrestrial ecosystems is one of the priority tasks in the case of climate and biosphere conservation. Significant is the role of soils, which are not only the main source of greenhouse gas emissions into the Earth's atmosphere but also a long-term reservoir that stores significant amounts of organic carbon in the form of soil humus. The article discusses the organization of monitoring of greenhouse gases at carbon polygons, the methods of sampling soil horizons, and methodological approaches to determine the content and stocks of organic carbon in soils. The importance of information on the qualitative and quantitative composition of soil organic matter and humic substances, which is necessary for the operation of modern simulation models and calculation of carbon units for the economic assessment of the direct and reverse carbon footprint have been revealed. Russia faces a number of challenges related to carbon offset and a low-carbon economy. The necessary volumes of monitoring data, which must be obtained at carbon polygons for the use of the ROMUL and Efimod models are considered. The necessity for an adequate spatial coverage of the territory of Russia with a network of carbon polygons is emphasized. Particular attention should be paid to the arctic territories that contain significant amounts of organic matter in permafrost and can become precursors of the formation and emission of significant amounts of carbon dioxide and methane into the atmosphere. [ABSTRACT FROM AUTHOR]

Global seaweed carbon sequestration estimates are currently taken as the fraction of the net primary production (NPP) exported to the deep ocean. However, this perspective does not account for CO2 from the consumption of external subsidies. Here, we clarify: (i) the role of export relative to seaweed net ecosystem production (NEP) for a closed system and one more likely open to subsidies; (ii) the importance of subsidies by compiling published estimates of NEP from seaweed-dominated ecosystems; and (iii) discuss their impact on the global seaweed net carbon balance and other sequestration constraints as a mitigation service. Examples of seaweed NEP (n  = 18) were sparse and variable. Nevertheless, the average NEP (−4.0 mmol C m–2 d–1 SE ± 12.2) suggested that seaweed ecosystems are a C source, becoming increasingly heterotrophic as their export is consumed. Critically, mitigation of greenhouse gas emissions was mixed relative to their replacement or baseline states, and where CO2 is supplied independently of organic metabolism and atmospheric exchange, we caution a sole reliance on NEP or NPP. This will ensure a more accurate seaweed mitigation assessment, one that does exceed their capacity and is effective within a compliance and carbon trading scheme. [ABSTRACT FROM AUTHOR]

The article reports that Alberta is a huge part of the national agriculture sector. Topics include considered that it has also been responsible for the highest level of agricultural greenhouse-gas emissions in the country as there has been little exploration to date of the effectiveness of using carbon credits to encourage Alberta farmers to practice farming techniques that lower emissions, while earning extra revenue without jeopardizing their agricultural output.

High concentrations of people and economic activities in urban areas have strengthened the links between cities, health and the environment. Cities are not only responsible for environmental and health problems but also they hold the key for a greener economy and a sustainable future. Urban built environment is a policy field where appropriate policies and actions could yield significant human and ecological benefits. Among different elements of urban built environment, buildings deserve particular attention due to their large contribution to environmental and health problems. The concept of sustainable (green) building is a recent response to address the problems that stem from the building sector. However, the widespread implementation of the concept is hindered by significant challenges. This paper argues that manifestation of multiple benefits that sustainable buildings deliver could help overcome some of these challenges. The paper presents the extent to which green buildings could generate co-benefits, and underlines the opportunities and barriers to push green building agenda forward. The results indicate that green and sustainably renovated buildings could yield significant benefits in terms of energy and CO 2 reduction, cost savings, and improved health situation for building users. The case study buildings with the best two performances are found to achieve 33% and 26% reduction in energy use intensity, and 38% and 32% reduction in CO 2 emissions intensity in comparison to benchmark values. Reduction in energy consumption in the top two buildings corresponds to an energy cost saving of $ 1–1.5 Million per year per building. Furthermore, the top two buildings are found to provide improved healthy environment due to improved indoor and ambient air quality, better thermal comfort and more natural lighting indoors. Making more explicit the multiple benefits of sustainable buildings needs further consideration in this regard. We recommend that the public sector could take key actions to accelerate the number of green buildings including fiscal support, technical assistance and policy reforms. [ABSTRACT FROM AUTHOR]

The ability of current global models to simulate the transport of CO2 by mid‐latitude, synoptic‐scale weather systems (i.e., CO2 weather) is important for inverse estimates of regional and global carbon budgets but remains unclear without comparisons to targeted measurements. Here, we evaluate ten models that participated in the Orbiting Carbon Observatory‐2 model intercomparison project (OCO‐2 MIP version 9) with intensive aircraft measurements collected from the Atmospheric Carbon Transport (ACT)‐America mission. We quantify model‐data differences in the spatial variability of CO2 mole fractions, mean winds, and boundary layer depths in 27 mid‐latitude cyclones spanning four seasons over the central and eastern United States. We find that the OCO‐2 MIP models are able to simulate observed CO2 frontal differences with varying degrees of success in summer and spring, and most underestimate frontal differences in winter and autumn. The models may underestimate the observed boundary layer‐to‐free troposphere CO2 differences in spring and autumn due to model errors in boundary layer height. Attribution of the causes of model biases in other seasons remains elusive. Transport errors, prior fluxes, and/or inversion algorithms appear to be the primary cause of these biases since model performance is not highly sensitive to the CO2 data used in the inversion. The metrics presented here provide new benchmarks regarding the ability of atmospheric inversion systems to reproduce the CO2 structure of mid‐latitude weather systems. Controlled experiments are needed to link these metrics more directly to the accuracy of regional or global flux estimates. Plain Language Summary: Global flux estimate systems use CO2 observations, atmospheric transport models, CO2 flux models (emissions and absorption), and mathematical optimization methods to estimate biosphere‐atmosphere CO2 exchange. Accurate representation of atmospheric transport is important for a reliable optimization of fluxes in these systems. We use intensive aircraft measurements of wind speed, boundary layer height, and horizontal and vertical differences of CO2 concentrations within 27 mid‐latitude cyclones collected by the Atmospheric Carbon Transport (ACT)‐America mission to evaluate the performance of ten global flux estimate systems from the Orbiting Carbon Observatory‐2 model intercomparison project (OCO‐2 MIP). We find the models can simulate observed horizontal CO2 differences between the warm and cold parts of cyclones with different degrees of success in summer and spring, but often underestimate the observed cross‐frontal and vertical differences in CO2 in winter and autumn. The models may underestimate the CO2 differences between the boundary layer and the free troposphere due to model errors in boundary layer height and surface fluxes. These weather‐oriented CO2 metrics provide benchmarks for testing simulations of the CO2 structure within cyclones. Future efforts are needed to link these metrics more directly to the accuracy of CO2 flux estimates. Key Points: Global inversion systems are able to simulate observed CO2 frontal differences but with varying degrees of successMost global inversion systems underestimate dormant‐season frontal and vertical CO2 differencesInversion systems appear to explain more of the model‐data differences in CO2 weather metrics than CO2 data sources [ABSTRACT FROM AUTHOR]

Climate change research is currently a topic of great interest for economic researchers. In particular, environmental input–output analysis increasingly plays an important role in measuring the economic and environmental effects of sustainable development policies in Europe. Other approaches also exist, such as econometric modelling, in which impacts are quantified on statistical grounds and with certain desirable properties (efficient estimates, confidence intervals, hypothesis testing, etc.) that are not found in the input–output approach. Consequently, this paper merges the two approaches to address the calculation of unbiased and consistent carbon dioxide emission multipliers for Denmark and their respective confidence intervals. The use of the supply and use system instead of the symmetric input–output table also presents the opportunity to avoid the common problems associated with the construction of technical coefficients (technology assumptions, negatives, etc.). Moreover, a new policy-relevant application of these multipliers is introduced: the quantification of the performance of the carbon dioxide emission reductions carried out by industries via external trading. [Copyright &y& Elsevier]

Atmospheric CO2 inversion typically relies on the specification of prior flux and atmospheric model transport errors, which have large uncertainties. Here, we used ACT‐America airborne observations to compare CO2 model observation mismatch in the eastern U.S. and during four climatological seasons for the mesoscale WRF(‐Chem) and global scale CarbonTracker/TM5 (CT) models. Models used identical surface carbon fluxes, and CT was used as CO2 boundary condition for WRF. Both models showed reasonable agreement with observations, and CO2 residuals follow near symmetric peaked (i.e., non‐Gaussian) distribution with near‐zero bias of both models (CT: −0.34±3.12 ppm; WRF: 0.82±4.37 ppm). We also found large magnitude residuals at the tails of the distribution that contribute considerably to overall bias. Atmospheric boundary‐layer biases (1–10 ppm) were much larger than free tropospheric biases (0.5–1 ppm) and were of same magnitude as model‐model differences, whereas free tropospheric biases were mostly governed by CO2 background conditions. Results revealed systematic differences in atmospheric transport, most pronounced in the warm and cold sectors of synoptic systems, highlighting the importance of transport for CO2 residuals. While CT could reproduce the principal CO2 dynamics associated with synoptic systems, WRF showed a clearer distinction for CO2 differences across fronts. Variograms were used to quantify spatial correlation of residuals and showed characteristic residual length scales of approximately 100–300 km. Our findings suggest that inclusion of synoptic weather‐dependent and non‐Gaussian error structure may benefit inversion systems. Key Points: CO2 observed by aircraft in Eastern U.S. compares well to models, but residuals are strongly non‐GaussianModel biases affect representation of cross‐frontal CO2 gradients governing CO2 transport in stormsInversion models may benefit from model‐data mismatch errors dependent upon synoptic sector [ABSTRACT FROM AUTHOR]

The Amazon River strongly modifies the biogeochemistry of the Western Tropical Atlantic (WTA). To disentangle the different mechanisms driving these modifications, we conduct a series of modeling experiments with a high‐resolution regional ocean model (ROMS) coupled to a biogeochemical/ecological model (BEC) that we augmented to include Diatom‐Diazotroph‐Assemblages (DDAs). In our model, the Amazon River increases net primary production (NPP) in the WTA by almost 10%, exceeding the stimulation expected from the supplied inorganic nitrogen and phosphorus by a factor of two. This amplification is fueled by new nitrogen stemming from DDA‐driven N2 fixation in the plume region, supported, in part, by the consumption of riverine dissolved organic phosphorus. The vertical export of organic carbon is enhanced by a shift of the phytoplankton community toward diatoms induced by the large amount of Si(OH)4 delivered by the Amazon. These changes in NPP and export production induce a strong uptake of atmospheric CO2. In contrast, the remineralization of the river‐delivered terrestrial organic matter leads to a release of CO2 over the WTA, which is partially offset by a net uptake induced by the riverine dissolved inorganic carbon and alkalinity. Overall, the Amazon reduces the strong outgassing of the WTA in our simulations by more than 50%. Our study demonstrates how rivers modify the marine biological pump and the air‐sea CO2 fluxes in the downstream ocean through a myriad of cascading effects, highlighting the need to fully consider the land‐ocean aquatic continuum in the modeling of the Earth System. Key Points: The Amazon River stimulates the biological pump in the WTA beyond a strict utilization of the riverine nutrientsDiatom‐diazotrophic assemblages, benefiting from the river supplied phosphorus, provide the required extra nitrogenThe Amazon‐driven stimulation of the biological pump induces a strong uptake of CO2 from the atmosphere [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) evasion from inland waters is an important component of the global carbon cycle. However, it remains unknown how global change affects CO2 emissions over longer time scales. Here, we present seasonal and annual fluxes of CO2 emissions from streams, rivers, lakes, and reservoirs throughout China and quantify their changes over the past three decades. We found that the CO2 emissions declined from 138 ± 31 Tg C yr−1 in the 1980s to 98 ± 19 Tg C yr−1 in the 2010s. Our results suggest that this unexpected decrease was driven by a combination of environmental alterations, including massive conversion of free-flowing rivers to reservoirs and widespread implementation of reforestation programs. Meanwhile, we found increasing CO2 emissions from the Tibetan Plateau inland waters, likely attributable to increased terrestrial deliveries of organic carbon and expanded surface area due to climate change. We suggest that the CO2 emissions from Chinese inland waters have greatly offset the terrestrial carbon sink and are therefore a key component of China's carbon budget. Inland waters emit greenhouse gases, but robust estimations are hampered by a dearth of spatio-temporally resolved measurements. Here the authors present annual fluxes of CO2 from Chinese inland waters over the past several decades, showing that emission fluxes have significantly declined since the 80s. [ABSTRACT FROM AUTHOR]

Carbon markets as a policy tool to mitigate emissions of greenhouse gases continue to be controversial, especially in developing countries. It is thus refreshing that Carton and Andersson (2017) undertook a field investigation of a transnational forest carbon offset project in Uganda. However, I am concerned that assumptions of structural Marxism that underwrite subsumption theory may have led the authors to see the project as inherently conflict ridden and exploitative and to neglect actual benefits. Their presentation of the project’s local impact jarred with my own empirical research into this project, undertaken in 2009, as well as more recent news accounts. While my field effort preceded the authors’ by 6 years, I attribute our different interpretations largely to theoretical and methodological differences. Evidence I present below suggests considerable alignment between the interests of transnational carbon markets and Ugandan smallholder farmers. Additional fieldwork might be able to resolve these differences in interpretation. [ABSTRACT FROM AUTHOR]

The article reports on a Global Carbon Index launched by Barclays Capital Inc., which will track the performance of carbon credits issued through major greenhouse gas emission trading schemes. According to reports, the index is meant to be a comprehensive benchmark for the carbon emission market and is governed by the Barclays Capital Environmental Market Index Committee. It mentions that the index initially will track carbon credits associated with the European Emissions Trading Scheme and the Kyoto Clean Development Mechanism and add new schemes as they develop. The index also offers investors direct and transparent access to the global carbon arena.

Agricultural systems models are essential tools to assess potential climate change (CC) impacts on crop production and help guide policy decisions. In this study, impacts of projected CC on dryland crop rotations of wheat-fallow (WF), wheat-corn-fallow (WCF), and wheat-corn-millet (WCM) in the U.S. Central Great Plains (Akron, Colorado) were simulated using the CERES V4.0 crop modules in RZWQM2. The CC scenarios for CO, temperature and precipitation were based on a synthesis of Intergovernmental Panel on Climate Change (IPCC ) projections for Colorado. The CC for years 2025, 2050, 2075, and 2100 (CC projection years) were super-imposed on measured baseline climate data for 15-17 years collected during the long-term WF and WCF (1992-2008), and WCM (1994-2008) experiments at the location to provide inter-annual variability. For all the CC projection years, a decline in simulated wheat yield and an increase in actual transpiration were observed, but compared to the baseline these changes were not significant ( p > 0.05) in all cases but one. However, corn and proso millet yields in all rotations and projection years declined significantly ( p < 0.05), which resulted in decreased transpiration. Overall, the projected negative effects of rising temperatures on crop production dominated over any positive impacts of atmospheric CO increases in these dryland cropping systems. Simulated adaptation via changes in planting dates did not mitigate the yield losses of the crops significantly. However, the no-tillage maintained higher wheat yields than the conventional tillage in the WF rotation to year 2075. Possible effects of historical CO increases during the past century (from 300 to 380 ppm) on crop yields were also simulated using 96 years of measured climate data (1912-2008) at the location. On average the CO increase enhanced wheat yields by about 30%, and millet yields by about 17%, with no significant changes in corn yields. [ABSTRACT FROM AUTHOR]

Enormous new markets in uncertainty and in carbon have been created recently, ostensibly to enhance the cost-effectiveness of both finance and climate action. In both cases, however, creating the abstract commodity framework necessary to make sense of the notion of 'cost-effectiveness' has entailed losing touch with what was supposedly being costed, helping to engender systemic crisis. The new financial markets expanded credit and multiplied leverage by isolating, quantifying, slicing, dicing and circulating diverse types of uncertainty; the resulting unchecked pursuit of liquidity led to a catastrophic drying up of liquidity. The carbon markets, meanwhile, by identifying global warming solutions with reductions in an abstract pool of tradable pollution rights and linking them with 'offsets' manufactured through quantitative techniques, ended up blocking prospective historical pathways toward less fossil fuel dependence and thus exacerbated the climate problem. Unsurprisingly, both markets have provoked strong, if diverse and confused, movements of societal self-defence. This pattern of action and reaction constitutes a chapter in the political history of commodification as significant in some ways as that describing the movements to commodify land and labour analysed by Karl Polanyi. [ABSTRACT FROM AUTHOR]

In this article we unpack the 'black box' of carbon offsetting through a critical examination of the technologies and techniques that create carbon credits. Drawing on empirical research of compliance (Clean Development Mechanism) and voluntary carbon offset markets, we highlight the diversity of technologies, techniques and devices involved in carbon offsetting, ranging from refrigerant plants to systems of calculation and audit. We suggest that polarised debates for and against offsetting do not adequately reflect the considerable variations between types of offset project and governance practices in the compliance and voluntary offset markets. Using conceptual insights from governmentality theory and science and technology studies we assess the tensions in making standard, fungible carbon credits. In conclusion, we suggest attention to the technologies and materiality of carbon offsetting allows a fresh perspective on somewhat entrenched debates about the advantages and disadvantages of offsetting. [ABSTRACT FROM AUTHOR]

The threats posed by climate change to the global environment have fostered heightened scientific and commercial interest in marine geo-engineering schemes designed to boost the capacity of the oceans to absorb atmospheric carbon dioxide. This is the primary goal of a process known as ocean fertilization, which seeks to increase the production of organic material in the surface ocean in order to promote further draw down of photosynthesised carbon to the deep ocean. This article describes the process of ocean fertilization, its objectives and potential impacts on the marine environment, and some examples of ocean fertilization experiments. It analyses the applicability of international law principles on marine environmental protection to this process and the regulatory gaps and ambiguities in the existing international law framework for such activities. Finally it examines the emerging regulatory framework for legitimate scientific experiments involving ocean fertilization being developed by the London Convention and London Protocol Scientific Groups and its potential implications for the proponents of ocean fertilization trials. [ABSTRACT FROM AUTHOR]

The article discusses the use of biochar in soils for carbon sequestration and reduction of atmospheric carbon dioxide. It notes the merits of biochar in improving crop yields in otherwise unproductive Amazon soils. Biochar, or charcoal, is the product of pyrolysis of plant material. Pyrolysis is a controlled incomplete- combustion process that minimizes carbon emissions and chemically fixes carbon in the charcoal product. The United Nations Convention to Combat Desertification (UNCCD) allocated biochar for consideration as a carbon mitigation strategy. A possible outcome is that biochar users could sell certified carbon emission reduction credits (CER).

Analyses of regional carbon sources and sinks are essential to assess the economical feasibility of various carbon sequestration technologies for mitigating atmospheric CO2 accumulation and for preventing global warming. Such an inventory is a prerequisite for regional trading of CO2 emissions. As a U.S. Department of Energy Southeast Regional Carbon Sequestration Partner, we have estimated the state-level terrestrial carbon pools in the southeast and south-central US. This region includes: Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Texas, and Virginia. We have also projected the potential for terrestrial carbon sequestration in the region. Texas is the largest contributor (34%) to greenhouse gas emission in the region. The total terrestrial carbon storage (forest biomass and soils) in the southeast and south-central US is estimated to be 130 Tg C/year. An annual forest carbon sink (estimated as 76 Tg C/year) could compensate for 13% of the regional total annual greenhouse gas emission (505 Tg C, 1990 estimate). Through proper policies and the best land management practices, 54 Tg C/year could be sequestered in soils. Thus, terrestrial sinks can capture 23% of the regional total greenhouse emission and hence are one of the most cost-effective options for mitigating greenhouse emission in the region. [ABSTRACT FROM AUTHOR]

This is a summary of the conversation among scholars attending the special session on "Responsibility, Opportunity, and Vision for Higher Education in Urban and Regional Carbon Management" at the First International Conference on Carbon Management at Urban and Regional Levels: Connecting Development Decisions to Global Issues in Mexico City Sept. 4-8, 2006. It includes The Declaration for Carbon Management Education, agreed upon by the participants. Obstacles to such a vision were discussed along with exemplar models of transdisciplinary curricula and suggestions for scholarship. [ABSTRACT FROM AUTHOR]