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Chemical oxygen demand (COD) is widely used as an organic pollution indicator in wastewater treatment plants. Large amounts of organic matter are removed during treatment processes to meet environmental standards, and consequently, substantial greenhouse gases (GHGs) such as methane (CH4) are released. However, the COD indicator covers a great amount of refractory organic matter that is not a pollutant and could be a potential carbon sink. Here, we collected and analysed COD data from 86 worldwide municipal wastewater treatment plants (WWTPs) and applied a model published by the Intergovernmental Panel on Climate Change to estimate the emission of CH4 due to recalcitrant organic compound processing in China’s municipal wastewater treatment systems Our results showed that the average contribution of refractory COD to total COD removal was 55% in 86 WWTPs. The amount of CH4 released from the treatment of recalcitrant organic matter in 2018 could have been as high as 38.22 million tons of carbon dioxide equivalent, which amounts to the annual carbon sequestered by China’s wetlands. This suggests that the use of COD as an indicator for organic pollution is undue and needs to be revised to reduce the emission of GHG. In fact, leaving nontoxic recalcitrant organic matter in the wastewater may create a significant carbon sink and will save energy during the treatment process, aiming at carbon neutrality in the wastewater treatment industry.

Pollution and climate change induced by fossil fuel usage are calling for the development of a circular bioeconomy based on carbon neutral resources such as marine macroalgae, also named seaweeds. Macroalgal biomass can generate biofuels and valuable bioproducts such as hydrocolloids and other unique biomolecules. Biorefinery of marine macroalgae involves a minimum use of energy and chemicals, and low waste generation, as demonstrated in recent laboratory-scale studies. Here, we review biorefinery of marine macroalgae with focus on non-energy bioproducts and advances in the separation of biomolecules. We found that metabolites with bioactive properties are in high demand for food, cosmetic, medicine and pharmaceutical industries. These metabolites can be obtained together with energy products to improve macroalgae valorization. Emerging extraction methods facilitate the generation of more qualitative bioproducts in higher yields with less energy.

A recent study by DeCicco et al. (Climatic Change 138:667–680, 2016) claims that corn used for ethanol should not be considered to be inherently biogenically carbon-neutral because not all that corn was grown additional to the level otherwise. By assessing the extent of carbon neutrality of corn for ethanol using the reference point baseline approach and historical data that study concluded that the carbon intensity of US corn ethanol is 27% higher than that of gasoline. We develop a framework to determine the carbon neutrality of corn for ethanol by assessing the additional carbon uptake by crops using an anticipated baseline approach. We also apply this framework to determine the additional corn produced for ethanol and include the direct life cycle carbon emissions of only that portion of corn in the direct life cycle carbon intensity of corn ethanol. We implement this framework by integrating an economic model of the agricultural sector in the USA with a biogenic carbon model and life cycle analysis to quantify biogenic carbon uptake and direct life cycle emissions with and without corn ethanol expansion over the 2007–2027 period. We find that the combined biogenic carbon emissions and direct life cycle carbon emission intensity of corn ethanol (not including indirect land use related emissions) is 21% lower than gasoline. The lower value of this carbon intensity of corn ethanol compared with gasoline is robust to a wide range of parametric assumptions.

In 2020, China promised to achieve carbon peaking by 2030 and carbon neutrality by 2060, and these targets are famous as “Goal 3060” in China. Chinese resource-based cities are concerned about the realization of Goal 3060 to practice national action against environmental change. In this paper, this study evaluates the impact of population, economic growth, energy intensity, industrial structure, fixed asset investment, and urbanization level on carbon emissions in Chinese cities. To do so, the paper divides 36 Chinese cities into four types (growing city, mature city, recessionary city, and regenerative city) from 2003 to 2017 by factor investigation according to the diverse development stages. The extended STIRPAT model is used to assess the impact of various factors on CO2 emissions in the Yellow River basin and diverse city levels. The panel regression analysis was conducted for the basin as a whole and cities at different development stages through a fixed-effects model and a linear regression model with Driscoll-Kraay standard errors. The results show that (1) the total carbon emissions in the Yellow River basin continued to climb during the study period. However, the growth rate slowed down significantly after 2012. In addition, there are differences in the total carbon emissions and growth rate of different cities. (2) Population, real GDP, energy intensity, industrial structure, and fixed asset investment all have a significant positive impact on carbon emissions in the overall basin except the urbanization level which has a significant negative influence on carbon emissions. (3) There is heterogeneity in the influencing factors of carbon emissions in resource-based cities at various development stages. Based on these results, corresponding policies are proposed for different types of cities to help resource-based cities achieve the 3060 dual carbon goal.

Green building development(GBD) plays an important role in improving carbon emission reduction efficiency of the construction industry(CEEOCI), and accelerating the construction industry to achieve carbon neutrality goals. In this paper, for the first time, the topic of "green building development promotes carbon neutrality in the construction industry" is included in the crossover research category of industrial economics and space economics. A framework for the analysis of the impact mechanism of GBD and CEEOCI under the dual perspective of "industry-space" is proposed. Based on China's provincial panel data from 2008 to 2019, using the intermediary adjustment model and the spatial Dubin model to analyze and test the industrial mechanism, spatial mechanism, and spatial effect attenuation boundary of the GBD effect on CEEOCI. The results show GBD is found to promote CEEOCI, and both the GBD and CEEOCI have a clear "center-periphery" spatial pattern. Meanwhile, the impact of GBD on CEEOCI has a "industry-space" two-dimensional mechanism. From an industrial perspective, GBD can change the supply-demand relationship of the construction market by promoting the greening of supporting industries in the construction industry and stimulating green consumption in the market, and ultimately achieve the overall improvement of CEEOCI. From a spatial perspective, GBD can form a new sectoral growth pole and provide elemental support for the improvement of CEEOCI through the polarization effect, but the polarization effect is higher in the range of 1000 km, while attenuation occurs outside the range of 1000 km. This paper provides not only a scientific and effective medium and macro analysis framework for green building development emission reduction performance evaluation but also a new theoretical basis and policy direction for the construction industry to improve carbon reduction efficiency and achieve industrial carbon neutrality.

With China already committing to peak carbon dioxide emissions before 2030 and achieving carbon neutrality before 2060, green development is urgent. It is necessary to clarify the driving mechanism of green development to design the path of green development scientifically. From the internal perspective of the green development system, this paper divides the green development power into external power and internal power. The external power is the political pressure formed by the public's green demands. The internal power is the endogenous power of green development transformed by the political promotion willingness of local government leaders. The research shows that (1) the green demands from the public and the accompanying political pressure can form the driving force of green development. (2) The political promotion intention has not been transformed into the endogenous driving force to promote green development in the research period. (3) The external driving force of public appeal is closely related to economic development, income and consumption levels, and education. This paper enriches the research literatures on the driving mechanism of green development and provides theoretical and practical exploration for the driving path of green development.

In recent years, the rapid rise of carbon dioxide concentration makes global warming increasingly serious, which leads to sea-level rise, coastal lowland inundation, glacier melting, extreme weather, species extinction and other environmental problems. China, as the largest carbon dioxide emitter, is facing climate change. In 2020, the Chinese government promised at the UN General Assembly to achieve the peak of carbon by 2030, and also put forward the goal of achieving carbon neutrality by 2060. To achieve the carbon peak and carbon in target, China needs to reduce the use of fossil energy and replace the use of fossil energy with renewable energy with less carbon dioxide emissions. Tidal energy, as a low-carbon renewable energy, is an important alternative to fossil energy. But can the tide be developed at the expense of the environment? In this paper, the impact of the development of tidal energy on the environment is analyzed and elaborated. According to the environmental impact, the solutions of developing environment-friendly tidal energy, wave energy and temperature difference energy are given. Based on this, policy suggestions are put forward to the Chinese government. The research results of this paper will provide reference for developing countries to develop and utilize tidal energy for power generation.

Subnational entities are recognizing the need to systematically examine options for reducing their carbon footprints. However, few robust and comprehensive analyses are available that lay out how US states and regions can most effectively contribute. This paper describes an approach developed for Georgia—a state in the southeastern United States called “Drawdown Georgia”, our research involves (1) understanding Georgia’s baseline carbon footprint and trends, (2) identifying the universe of Georgia-specific carbon-reduction solutions that could be impactful by 2030, (3) estimating the greenhouse gas reduction potential of these high-impact 2030 solutions for Georgia, and (4) estimating associated costs and benefits while also considering how the solutions might impact societal priorities, such as economic development opportunities, public health, environmental benefits, and equity. We began by examining the global solutions identified by Project Drawdown. The resulting 20 high-impact 2030 solutions provide a strategy for reducing Georgia’s carbon footprint in the next decade using market-ready technologies and practices and including negative emission solutions. This paper describes our systematic and replicable process and ends with a discussion of its strengths, weaknesses, and planned future research.

Increased awareness of climate change has precipitated more stringent mitigation targets. Public sector institutions in Canada are committed to becoming carbon neutral to attain a leadership position in climate change mitigation-related initiatives. Recent statistics reveal that buildings account for the majority of the corporate carbon footprint of public sector institutions. Hence, there is an increasing interest towards developing net zero energy and net zero emission buildings to comply with climate action targets. With limited financial resources, public sector institutions must optimize investments into building energy retrofits by considering lifecycle cost (LCC), overall energy performance, and related greenhouse gas (GHG) emission. The aim of this paper is to develop an investment planning approach for net zero emission buildings (NZEB). First, an investment planning approach for NZEB is proposed. A typical recreational centre building in British Columbia, Canada, was used as the archetype to demonstrate the concept. Second, innovative and proven building energy retrofits were analysed using energy simulation software to assess the impact on energy consumption reduction, GHG emissions, and LCC. Third, impacts of geographical location, tariff regimes, and grid emission factors on energy retrofits were studied by locating the same building in other provinces of Canada. This study revealed that net zero energy investment has a strong correlation to the grid emission factor. The proposed approach in this paper will assist building managers and owners in retrofitting and budget planning.

Greenhouse gas (GHG) emissions related to human activities have significantly caused climate change since the Industrial Revolution. China aims to achieve its carbon emission peak before 2030 and carbon neutrality before 2060. Accordingly, this paper reviews and discusses technical strategies to achieve the "dual carbon" targets in China's metal mines. First, global carbon emissions and emission intensities from metal mining industries are analyzed. The metal mining status and carbon emissions in China are then examined. Furthermore, advanced technologies for carbon mitigation and carbon sequestration in metal mines are reviewed. Finally, a technical roadmap for achieving carbon neutrality in China's metal mines is proposed. Findings show that some international mining giants have already achieved their carbon reduction targets and planned to achieve carbon neutrality by 2050. Moreover, improving mining efficiency by developing advanced technologies and replacing fossil fuel with renewable energy are two key approaches in reducing GHG emissions. Green mines can significantly benefit from the carbon neutrality process for metal mines through the carbon absorption of reclamation vegetations. Geothermal energy extraction from operating and abandoned metal mines is a promising technology for providing clean energy and contributing to the carbon neutrality target of China's metal mines. Carbon sequestration in mine backfills and tailings through mineral carbonation has the potential to permanently and safely store carbon dioxide, which can eventually make the metal mining industry carbon neutral or even carbon negative.

China’s recently announced directive on tackling climate change, namely, to reach carbon peak by 2030 and to achieve carbon neutrality by 2060, has led to an unprecedented nationwide response among the academia and industry. Under such a directive, a rapid increase in the grid penetration rate of solar in the near future can be fully anticipated. Although solar radiation is an atmospheric process, its utilization, as to produce electricity, has hitherto been handled by engineers. In that, it is thought important to bridge the two fields, atmospheric sciences and solar engineering, for the common good of carbon neutrality. In this überreview, all major aspects pertaining to solar resource assessment and forecasting are discussed in brief. Given the size of the topic at hand, instead of presenting technical details, which would be overly lengthy and repetitive, the overarching goal of this review is to comprehensively compile a catalog of some recent, and some not so recent, review papers, so that the interested readers can explore the details on their own.

In a monopolistically competitive model with production externalities, where individuals voluntarily provide offsets which compensate for degradation of environmental quality caused by their income earning activities, this paper examines how an increase in the population size affects the equilibrium levels of environmental quality, offsets, and net contributions. Whether labor supply is institutionally constrained or not, as the population size increases, environmental quality decreases and converges to zero. However, since offsets increase and converge to the degradation rate of environmental quality, the carbon neutrality theorem holds: net contributions are zero. These results are independent of the specification of the utility function.

Carbon neutrality lays out a grand blueprint for carbon emission reduction and climate governance in China. How to reduce energy consumption is the key to achieving this goal. The economic development and energy consumption show a very large gap at the provincial level, and this paper divides China into six regions (North, Northeast, East, Mid-South, Southwest, and Northwest) and analyzes the dynamic changes and reveals the driving factors that have affected CO2 emission changes from 1997 to 2017. Then, the driving forces including energy intensity, energy structure, energy efficiency, economic activity, and population scale were discussed employing the logarithmic mean Divisia index (LMDI) based on provincial panel data. The results show that CO2 emissions from energy consumption show an upward trend, from 4145 Mt in 1997 to 13,250 Mt in 2017, with an annual average growth rate of 1.06%; coal consumption is the main source of CO2 emission. The regions with the highest proportion of CO2 emissions are the East and North, which account for 50% of total emissions. China’s CO2 emissions from energy consumption, coal consumption, and output have shown significant spatial autocorrelation at the provincial scale. According to coal consumption, energy consumption CO2 emissions are divided into three stages: phase I (1997–2002), the increase in CO2 emissions in six regions was attributed to significant and positive impacts of energy intensity, economic activity, and population scale, the effects of which exceeded those of the energy structure and energy efficiency; phase II (2003–2012), the economic activity effect on CO2 emissions was highest in the East region, followed by the North and Mid-South regions; phase III (2013–2017), the East, Mid-South, and Southwest regions of China were dominated by the positive effects of energy intensity, economic activity, and population scale. The major driver of CO2 emissions is economic activity; the energy efficiency effect is an important inhibitory factor. Regional economic development and energy consumption in China are unbalanced; we conclude that differentiated emission reduction measures should be of particular concern for policymakers.

Recently, China has declared its national objective of becoming carbon neutral by 2060. Hence, mitigating carbon dioxide emissions has become an important agenda of the Chinese government. Against this backdrop, this paper aims to evaluate the effectiveness of pursuing expansionary fiscal and monetary policies on China’s carbon dioxide emission figures by using annual frequency data from 1980 to 2018. Accordingly, this study considers the levels of government expenditure and broad money supply as fiscal and monetary policy instruments, respectively. Besides accounting for structural break concerns in the data, the findings from the empirical analysis reveal that there are long-run associations between carbon dioxide emissions, economic growth, and fiscal and monetary expansion in China. Moreover, the results also show that in both the short- and long-run expansionary fiscal policy trigger higher carbon dioxide emissions while expansionary monetary policy inhibits the carbon dioxide emission figures of China. Furthermore, the results invalidate the existence of the Environmental Kuznets Curve hypothesis since the relationship between China's economic growth and carbon dioxide emissions is evidenced to portray an N-shape. In line with these findings, it is recommended that China achieve environmentally sustainable economic growth by aligning the national fiscal and monetary policies with the 2060 carbon-neutrality objective.

Sichuan Basin (SCB) is a typical basin in southwest China and a traditional smog-prone area. Control of air pollution in this area is particularly critical in achieving China’s carbon emission peak and carbon neutral goals. It is characterized by high population density, heavy transportation, rapid industrialization, complex topography, and meteorological conditions. However, the air pollution studies of SCB remain the sparse and in-depth studies are still warranted. None of the previous research has synthetically reviewed the status of air pollution in this region. This paper comprehensively overviewed the air pollution of SCB from five aspects: air pollution characteristics, sources of air pollutants, driving factors of air pollution, air pollution episodes and health risks. A comparison on the air pollution of typical megacities in the basin was also discussed. The findings and shortcomings of the existing studies were also summarized. Recommendations for future research directions were also proposed.

In order to limit global warming to 2 °C, countries have adopted carbon capture and storage (CCS) technologies to reduce greenhouse gas emission. However, it is currently facing challenges such as controversial investment costs, unclear policies, and reduction of new energy power generation costs. In particular, some CCS projects are at a standstill. To promote the development of CCS projects in different countries, this paper reviews and compares energy conservation and emission reduction policies and different national goals. From a policy perspective, CCS-driven policies are analyzed. Based on this, corresponding policy recommendations are put forward, in order to promote the healthy development of global CCS technology and deal with climate issues more effectively. With less than 10 years away from the short-term goal, promoting the development and application of CCS projects requires scientific research from universities, enterprises and governments in order to attain zero or negative CO2 emission. On the basis of focusing on the development of CCS technology, according to the actual situation of each country, the appropriate application of CCS engineering should focus on the development of science and technology, rather than a unified requirement around the world., Carbon Neutrality, 1 (1)

After the Paris Climate Conference (COP21), countries worldwide are making progress toward carbon neutrality targets. However, despite flourishing economically, emerging countries fail to ensure environmental sustainability. Hence, it is crucial for these countries to identify the macroeconomic factor that could address the ecological concerns. Therefore, this paper examines the linkage between environmental innovations, energy productivity, economic globalization, and economic growth on environmental degradation in emerging countries. Based on the data from 1990 to 2017, the study applies the advanced panel data estimation tool cross-sectional autoregressive distributed lags (CS-ARDL) for the long-run and short-run empirical estimation that allows cross-sectional dependence and heterogeneity in slope parameters. The empirical results unveil that environmental innovations and energy productivity significantly improve environmental quality by reducing the ecological footprint. Moreover, the results unfold that economic globalization worsens the environmental quality by exacerbating the ecological footprint, while an inverted U-shaped relationship between environmental degradation and economic growth confirms the validity of the environment Kuznets curve in emerging countries. Results suggest that the government should develop such strategies that encourage environmental innovations and energy productivity to balance the speed of economic globalization and economic growth.

Reaching the peak of carbon dioxide emissions is the basis and premise of carbon neutrality. In this paper, the factor decomposition model was used to analyze the influencing factors and effects of carbon dioxide emissions. Causal chain model of elastic decoupling was established. The historical decoupling state between carbon dioxide emissions and economic growth and the decoupling effect of its influencing factors were analyzed. The prediction model of carbon dioxide emissions was used to explore the change trend of China’s carbon dioxide emissions and its peak in the short and medium term in the future. The elastic decoupling trend between carbon dioxide emissions and economic growth was predicted. The results show that economic growth is the main force driving carbon dioxide emissions. Both energy intensity and energy consumption structure have a strong inhibiting effect on carbon dioxide emissions except for a few years, but the former has a more significant inhibiting effect than the latter. In general, the elastic decoupling between carbon dioxide emissions and economic growth has experienced a state from weak decoupling to growth linkage and then to weak decoupling. And this weak decoupling trend will continue to increase in the short and medium term. During the 14th Five-year and 15th Five-year period, if the average annual economic growth rate will be maintained at 4.61–5.85%, and energy intensity will be reduced by 16.14–18.37%, and the proportion of non-fossil energy in the energy consumption structure at the end of the 14th, 15th and 16th Five-Year Plan period will be around 19.9%, 23.2% and 26.1%, respectively, then the intensity of carbon dioxide emissions will continue to decline. It is expected to reach the peak of carbon dioxide emissions between 10,453 and 10,690 billion tons from 2025 to 2027. And the earlier the peak time is, the smaller the peak is, which would provide valuable time for carbon neutrality and room to reduce carbon dioxide emissions in the medium and long term.

The terrestrial carbon cycle is an important component of global biogeochemical cycling and is closely related to human well-being and sustainable development. However, large uncertainties exist in carbon cycle simulations and observations. Model-data fusion is a powerful technique that combines models and observational data to minimize the uncertainties in terrestrial carbon cycle estimation. In this paper, we comprehensively overview the sources and characteristics of the uncertainties in terrestrial carbon cycle models and observations. We present the mathematical principles of two model-data fusion methods, i.e., data assimilation and parameter estimation, both of which essentially achieve the optimal fusion of a model with observational data while considering the respective errors in the model and in the observations. Based upon reviewing the progress in carbon cycle models and observation techniques in recent years, we have highlighted the major challenges in terrestrial carbon cycle model-data fusion research, such as the “equifinality” of models, the identifiability of model parameters, the estimation of representativeness errors in surface fluxes and remote sensing observations, the potential role of the posterior probability distribution of parameters obtained from sensitivity analysis in determining the error covariance matrixes of the models, and opportunities that emerge by assimilating new remote sensing observations, such as solar-induced chlorophyll fluorescence. It is also noted that the synthesis of multisource observations into a coherent carbon data assimilation system is by no means an easy task, yet a breakthrough in this bottleneck is a prerequisite for the development of a new generation of global carbon data assimilation systems. This article also highlights the importance of carbon cycle data assimilation systems to generate reliable and physically consistent terrestrial carbon cycle reanalysis data products with high spatial resolution and long-term time series. These products are critical to the accurate estimation of carbon cycles at the global and regional scales and will help future carbon management strategies meet the goals of carbon neutrality.

Climate change mitigation and adaptation are common global challenges, and how to accelerate carbon neutrality and green recovery is a major global issue. Market-oriented emission reduction policy has been widely concerned for its unique advantages, but most of the current market-oriented emission reduction policies are based on the consideration of end-of-pipe governance and lack of effective control of source reduction. Energy quota trading (EQT) is an innovation of an energy-saving and emission reduction system, which is based on the idea of source reduction. However, it is unknown about the evaluation of the effect of the EQT policy from the macro perspective. Based on the related statistical data of energy consumption, combined with the ARIMA model, STIRPAT model, and the synthetic control method (SCM), this paper analyzes the energy consumption distribution in China from 2001 to 2020 and comprehensively evaluates the effect of EQT in the pilots. The results show that: (1) The overall energy consumption in China shows a steady upward trend, and its distribution is unbalanced. (2) In absolute perspective, EQT can realize the “double control” of the total amount and intensity in energy saving and emission reduction, and the intensity control effect is better than the total amount control effect. (3) In relative perspective, EQT can enhance the potential of energy saving and emission reduction in the pilots, in which it needs to take the regional characteristics into account. The policy effect is still significant when eliminating some unobservable factors, which indicate that the policy is effective and can be replicated nationwide. The study comprehensively evaluates the effect of ETS from multiple perspectives, which can effectively avoid the misjudgment of the policy effectiveness caused by the single dimension evaluation, while it can also be used as a reference for the government to perfect the policies of energy management system and emission control system. Furthermore, the development of EQT is an important catalyst for policymakers to coordinate policies to accelerate the achievement of carbon-neutral targets and a more resilient low-carbon development model.

This paper reviews the status of the research on industrial hydrogen production technology and development in China. The pros and cons of different hydrogen production technologies are compared. In addition, it is also conducted a comprehensive analysis of hydrogen production technology from economic and environmental aspects. Finally, the opportunities and challenges faced by the development of China’s hydrogen production technology are analyzed. In China, hydrogen production technology from fossil fuels such as coal and natural gas is relatively mature. Among them, hydrogen production by coal gasification and/or methane steam reforming have achieved large-scale applications. But its biggest problem is large carbon emissions, which does not meet China’s the development plan of "peaking carbon dioxide emissions and carbon neutrality." Hydrogen production technology through water electrolysis has many advantages, such as cleanness, pollution-free, and high purity of the hydrogen. However, it has the disadvantages of large power consumption and high hydrogen production cost. China has abundant renewable resources, but the technology for hydrogen production from renewable energy is still in its infancy and its development is not yet mature. Through comprehensive analysis, we believe that China should continue to develop new technologies while maintaining the advantages of traditional fossil fuel hydrogen production technologies. At the same time, China should also make full use of China’s remaining wind, light, electricity and biomass resources to develop green hydrogen production technologies such as electrohydrolysis. Through the above-mentioned various measures, it will effectively promote the transformation of China’s energy structure and realize the diversification of the hydrogen industry in the true sense.

International audience; The new European Commission for 2019–2024 proposed the European Green Deal with renewed ambition for climate and environment policies to achieve carbon neutrality and a toxic-free environment by 2050. Accordingly, the Farm to Fork and the new Biodiversity Strategies, issued in 2020, set quantitative objectives for fertilisers, pesticides and antimicrobials, organic farming and high-diversity landscapes by 2030. Livestock is directly and indirectly responsible for a large proportion of agricultural greenhouse gas emissions with its feed and forage demand, and agriculture and livestock must undergo radical changes to align. The present policy and financial means, including the Common Agricultural Policy, have proved unable to put the EU farm and food sector on the right track. The policy proposals that I defended in the 2019 France Stratégie Report on the CAP employ public economic principles. Reducing polluting inputs and waste with sound innovations in the farm and food sector needs a coherent policy framework. The Green Deal ambition also requires radical changes in income and social surplus distributions as well as in EU consumers’ diets, corresponding to far higher taxes and subsidies than usually considered in academic papers.; La nouvelle Commission européenne pour la année 2019-2024 a proposé le pacte vert pour l’Europe avec une ambition renouvelée pour les politiques en matière de climat et d’environnement afin d’atteindre la neutralité carbone et un environnement sans substances toxiques d’ici 2050. En conséquence, la ferme à la fourchette et les nouvelles stratégies pour la biodiversité, publiées en 2020, fixent des objectifs quantitatifs pour les engrais, les pesticides et les antimicrobiens, l’agriculture biologique et les paysages à haute diversité d’ici 2030. Le bétail est directement et indirectement responsable d’une grande partie des émissions de gaz à effet de serre agricoles en proportion de sa demande d’aliments et de fourrage, et l’agriculture et l’élevage doivent subir des changements radicaux pour s’aligner. La politique et les moyens financiers actuels, y compris la politique agricole commune, se sont avérés incapables de mettre le secteur agricole et alimentaire de l’UE sur la bonne voie. Les propositions politiques que j’ai défendues dans le Rapport De Stratégie France 2019 sur la PAC s’emploient des principes économiques publics. Réduire les intrants polluants et les déchets grâce à des innovations solides dans le secteur agricole et alimentaire nécessite un cadre politique cohérent. L’ambition du pacte vert nécessite également des changements radicaux dans les distributions de revenus et de surplus sociaux ainsi que dans l’alimentation des consommateurs de l’UE, ce qui correspond à des impôts et des subventions beaucoup plus élevés que ceux habituellement considérés dans les documents universitaires.

The European Green Deal announced by the European Commission in December 2019 is a roadmap meant to foster the transition of the European Union towards the climate-neutral economy by reducing carbon emissions towards 55% by 2030 and achieving carbon neutrality by 2050. By putting the EGD in a boarder perspective of evolving, constitutional rationale of environmental protection in the EU legal order, this contribution examines horizontal, legal dimension and financial implications of the green transition. The challenge ahead of the Union is now how to transform the ambitious climate agenda into efficient legal and economic instruments ‘in a fair way, leaving no one behind’. This paper argues that EGD is a great opportunity, but in order to turn it into a success, it must be strongly anchored in the concepts pertaining to the constitutional framework of the EU legal order, in particular, the concepts of solidarity, sustainable development and high level of environmental protection.

Carbon dioxide capture and storage (CCS) technology is an effective CO2 fixation technology, as documented by the special report produced by Working Group III of the Intergovernmental Panel on Climate Change. Today, this technology has become important due to the threat of global warming and climate change. Furthermore, the development of carbon dioxide capture and utilization (CCU) technology, which reuses the captured CO2, has been prioritized in recent years to accelerate the deployment of “CCUS.” For both utilization and storage, CO2 capture is a key process that determines how efficiently decarbonation is able to meet the global target. Regardless of the maturity of various types of CO2 capture technologies, amines are the most widely used chemical species. This paper contains a brief overview of CCUS followed by a discussion of several aspects of amine-based CO2 capture technologies. Carbon dioxide capture and storage (CCS) technology has become important due to the threat of global warming and climate change. Furthermore, the development of carbon dioxide capture and utilization (CCU) technology, which reuses the captured CO2, has been prioritized in recent years to accelerate the deployment of “CCUS.” Amine-based CO2 capture is a key process for realizing a carbon neutral society.

With the national goal of "carbon peak by 2030 and carbon neutral by 2060 in China", studies on carbon prices of China's Emissions Trading System (ETS) pilots have shown growing interest in the related fields. Carbon price fluctuations reflect the scarcity of carbon resources, and accurate prediction can improve carbon asset management capabilities. Therefore, in order to clarify the dynamics of carbon markets and assign carbon emissions allocation rationally, we propose a hybrid feature-driven forecasting model with the framework of decomposition-reconstruction-prediction-ensemble. In this paper, the non-stationary, nonlinear and chaotic characteristics of carbon prices in China's ETS pilots have been verified, and then the prediction model is built based on the tested features. Firstly, the original carbon price series are decomposed by Variational Mode Decomposition (VMD), and then reconstructed by Sample Entropy (SE). Next, Extreme Learning Machine (ELM) optimized by Particle Swarm Optimization (PSO) is conducted to predict the subsequences. Lastly, the forecasting series of every subseries are summed to obtain the final results. The empirical results based on carbon prices of China's ETS pilots proved that the proposed model performs more efficiently than the current benchmark models. As carbon prices are expected to increase across all ETS during the post-COVID-19 recovery stage, the new prediction model will be useful for improving the guiding principles of the existing government policies including the likely introductions of Border Carbon Adjustment (BCA) in the EU and the US, and governing the large global public companies to deliver their "net zero" commitments.

Technologies evolve under the impact of several factors starting from the progress of science and innovation. Usually driven by market forces, the evolution is slow. With regard to energy, the time unit is roughly a century. Concerns about climate change add a new element: political decisions. The EU committed itself at the end of 2019 to achieving carbon neutrality by 2050, mainly through the implementation of wind and solar energies. A comparison between past data and forecasts related to the change sets the difficulties clearly in evidence. The paper discusses the requirements for the European Green Deal to be successful.

The global warming induced by the emission of greenhouse gases, especially the carbon dioxide, has become the global climate and environmental issues. China has been working in the CO2 emission reduction and carbon sinks with the purpose of becoming the carbon-neutral country by 2060. The CO2 capture, utilization and storage (CCUS) technologies and the reforestation technology represented by the Conversion of Cropland to Forestland Program (CCFP) have great potential for sinking CO2 emission. However, the trade-off among CCFP, CCS/CCUS and Water-Energy-Food (WEF) nexus are not well evaluated. In this paper, the remote-sensing data are collected and used to evaluate the sustainability of CCFP by analyzing the variation of land use and land cover (LULC), crop production, etc. The results show that 13.29% of the cropland in 2001 vanished and converted to grassland (8.3%), mosaic cropland (3%) and urban land (0.98%) in 2019, demonstrating that the CCFP is successful in both WEF nexus and carbon sink. The total crop production has increased around 50% between 2001 and 2019, implying that the CCFP will not lead to the food risk during the conversion of croplands into other types of land in China. A sustainable implementation of CCFP and other environmental Payments for Ecosystem Services (PES) policies in 2019–2060 could reach an estimated total growth of 7.462 billion m3 in comparison of that in 2018 and the total plantation forest stock of about 10.852 billion m3 in 2060, with a corresponding minimum CO2 sink of 2.90 billion tons in 2060. The estimated peak of net equivalent CO2 emissions before 2030 is about 11.0 billion tons and could not be reduced to zero by 2060 without the large-scale application of the CCS/CCUS technologies as geological sequestration of CO2. Besides, the application of CCS/CCUS can be beneficial for WEF, e.g., through replacing the water by CO2 during energy production, especially in the shale gas production in the regions with high water risks in China. In one word, CCS/CCUS and CCFP are two decided pathways of carbon sequestration and should be systematically applied to achieve China’s carbon neutrality by 2060.

Lignocellulosic biomass is carbon neutral and produces fuels and chemicals which are used for domestic, industrial, and transportation system. Thermochemical conversion processes (combustion, gasification, and pyrolysis) are emerging technologies which have great potential for industrial implementation. In this paper, the investigation has been done to select appropriate bamboo biomass suitable for thermochemical conversion process out of 21 biomass samples available in Mizoram, India. Various characteristics considered here for the selection of the appropriate bamboo biomass include proximate analysis, ultimate analysis, and their heating values. These characteristics are plotted in different diagrams and analysed in detail. It is observed after analysis that some bamboo biomasses are suitable combustion, some are suitable for pyrolysis and rest are suitable for gasification.

In this paper we explore the competition between variable renewable energy sources (VRE) and a carbon-neutral baseload technology in the transition to a low-carbon power system. We study a stylized system subject to a gradually increasing carbon tax using an agent-based model where agents are power companies investing in new capacity. The agents make predictions of the profitability of different investment options. Five electricity generating technologies are available in the model: coal, gas, wind, solar PV and a more expensive carbon-neutral baseload technology. We compare the output from our model with a corresponding optimization model. We present two main findings: (1) installed capacity of VRE initially increases with a carbon tax. However, once the carbon tax has reached a certain level the installed capacity of VRE starts to decline due to competition with the stylized carbon-neutral baseload technology. (2) With limited foresight we find that the model underinvests (first 25 years) in wind and then overinvests in wind compared to the optimal solution. The reasons for these dynamic phenomena are explained and an extensive sensitivity analysis is carried out.

The objective of this paper is to analyse role of forest industry in meeting energy and climate targets that aim to mitigating global change. Finland as an important forest industry country with the ambitious target of becoming carbon neutral by 2035 is selected to a target county. This study aims to present a plausible assessment of the future of the Finnish forest industry until 2035 based on literature and a scenario building approach. The focus is on energy use and fossil carbon dioxide (CO2) emissions. The results suggest that electricity consumption will decrease, whereas electricity production will increase, which indicates that forest industry can provide more renewable electricity to the grid. Heat consumption may even increase as a result from building new biorefineries, but those mills can most probably meet their heat demand by combusting biofuels. Changes in forest industry’s direct fossil CO2 emissions can reduce Finnish fossil CO2 emissions 2─4% in comparison to 2018. Biofuels production is likely to rise, but the extent remains to be seen. It is concluded that the Finnish forest industry can contribute significantly to meeting national climate policy targets, and forest industry in general can play a role in mitigating global change. Additionally, it was found that development of the Finnish forest industry will probably be limited by the requirement for sustainable wood harvesting, which may also be a problem for other forest industry countries.

In a general equilibrium model where individuals voluntarily provide offsets which compensate for degradation of environmental quality by consuming differentiated goods produced by monopolistically competitive firms, this paper examines how the population size affects the equilibrium levels of offsets and net contributions. The results depend on the specification of the utility function. However, when environmental quality converges to a finite level, the offsets are independent of this specification in a large economy with many individuals. Offsets are positive in the large economy, and “carbon neutrality” holds: Net contributions are zero. The comparative statics of parameters are also analyzed.

The impact of substituting biofuels for fossil fuels on carbon dioxide (CO2) emissions has been debated for many years. A reason for the lack of resolution is that the method widely used to address the question, lifecycle analysis (LCA), is subjective. Its results irreducibly depend on untestable assumptions, notably those pertaining to system boundaries but also those for representing market effects. The best one can do is empirically constrain estimates of net CO2 impact using data that characterize important aspects of the overall system. Our 2016 paper, “Carbon balance effects of U.S. biofuel production and use,” took such an approach, using field data to estimate the direct CO2 exchanges for a circumscribed vehicle-fuel system over the 2005–2013 period of expanding US biofuel use. De Kleine and colleagues criticize our work because it does not follow LCA conventions, arguing in particular for the primacy of the assumption that biofuels are inherently carbon neutral. This response refutes their critique; it reminds readers why the lifecycle paradigm fails for a dynamic system involving the terrestrial carbon cycle, stresses the need to bound an analysis of key carbon exchanges, and explains why the circular logic of LCA can be so beguiling.

Urban expansion increases the need for, and pressure on, green areas. Reforestation projects in the rural–urban fringe represent an opportunity for enhancing the environmental quality of peri-urban spaces and a means to contribute to cities carbon neutrality policies. Yet, relatively little information exists regarding the long term (10–25 years) survival and growth rate in urban and peri-urban plantations. This paper reports and discusses the results achieved by a reforestation in the peri-urban space of Rome (Italy), 25 years after its establishment. The plantation has been periodically surveyed between 6 and 24 years of age by means of continuous inventories, with the aim of monitoring growth dynamics. Permanent sample plots have been investigated and stratified by tree species composition (broadleaves vs. conifers, single vs. multispecies) for data analysis. On the whole, plantations show suitable results in terms of rate of growth, carbon storage and uptake, especially in coniferous and mixed stands. The average stand volume of the forest plantation, currently ranges from one-and-a third to one-and-a-half times the average values estimated for natural high forest stands of the same age and species groups at country level. The species groups exhibit differential growth patterns over the observed period, that are mainly due to differences in the ecological traits of the planted trees. Ten years after the establishment, the average annual value of carbon uptake in conifer and mixed species group exceeds 10 Mg CO2 equivalent ha-1 year-1, a figure corresponding to 4 times the value of deciduous broadleaves (oaks and other species) and 1.5 times the value of evergreen oaks. Twenty years after the establishment, the average annual carbon uptake peaks to 25 Mg CO2 equivalent ha-1 year-1 in the mixed species group, exceeds 15 Mg CO2 equivalent ha-1 year-1 in the conifers, and ranks between 6 and 12.5 Mg CO2 equivalent ha-1 year-1 in the groups dominated by broadleaved species. Overall with a surface area just under 300 ha, the carbon uptake level of the Castel di Guido reforestation allows to offset the 0.04% of CO2 emissions of the city of Rome. Although the spatial coexistence of even-aged plantation blocks characterized by a range of ecological traits, is expected to ensure a more continuous carbon sequestration, being less susceptible to damage of any kind, the current lack of silvicultural management may also lead to degradation processes, by triggering e.g. fuel accumulation and, by consequence, forest fires. In this line, recommendations are provided in order to improve the ecological and functional efficiency of the investigated reforestation. The field experiment demonstrates, ultimately, the capability of the continuous forest inventory to take the pulse over several decades of tree species performance and carbon uptake levels in urban and peri-urban reforestations.

In the 21st century, sustainability is widely regarded as the new corporate culture, and leading manufacturing companies (Toyota, GE, and Alcoa) and service companies (Google and Federal Express) are striving towards carbon neutrality. The current carbon footprint of the global aluminum industry is estimated at 500 million metric tonnes carbon dioxide equivalent (CO2eq), representing about 1.7% of global emissions from all sources. For the global aluminum industry, carbon neutrality is defined as a state where the total “in-use” CO2eq saved from all products in current use, including incremental process efficiency improvements, recycling, and urban mining activities, equals the CO2eq expended to produce the global output of aluminum. This paper outlines an integrated and quantifiable plan for achieving “carbon neutrality” in the global aluminum industry by advocating five actionable steps: (1) increase use of “green” electrical energy grid by 8%, (2) reduce process energy needs by 16%, (3) deploy 35% of products in “in-use” energy saving applications, (4) divert 6.1 million metric tonnes/year from landfills, and (5) mine 4.5 million metric tonnes/year from aluminum-rich “urban mines.” Since it takes 20 times more energy to make aluminum from bauxite ore than to recycle it from scrap, the global aluminum industry could set a reasonable, self-imposed energy/carbon neutrality goal to incrementally increase the supply of recycled aluminum by at least 1.05 metric tonnes for every tonne of incremental production via primary aluminum smelter capacity. Furthermore, the aluminum industry can and should take a global leadership position by actively developing internationally accepted and approved carbon footprint credit protocols.

Energy issues are important and consumption is slated to increase across the globe in the future. The energy-environment nexus is very important as strategies to meet future energy demand are developed. To ensure sustainable growth and development, it is essential that energy production is environmentally benign. There are two temporal issues—one that is immediate, and needs to address the environmental compliance of energy generation from fossil fuel sources; and second that is the need to develop newer alternate and more sustainable approaches in the future. Aerosol science and technology is an enabling discipline that addresses the energy issue over both these time scales. The paper is a review of aspects of aerosol science and engineering that helps address carbon neutrality of fossil fuels. Advanced materials to meet these challenges are discussed. Future approaches to effective harvesting of sunlight that are enabled by aerosol studies are discussed.

Fuelwood plays an important role in the rural economy of the developing countries of Asia and Africa. Optimizing energy fixation in forest trees through high density energy plantations (HDEP), gasification of wood, and conversion of forest tree biomass, are some of the potential areas whereby additional research and development input for efficient management of atmospheric carbon in our energy system can be incorporated. For example, the photosynthetic efficiency of forest trees is rarely above 0.5%, which on the basis of theoretical considerations can be increased by up to 6.6%. Thus there is an ample scope to improve the efficiency up to 1%, which amounts to doubling of the productivity of the forests. Recent policy changes and experiences with wood-based bio-energy programmes in several countries indicate that woodfuels may become increasingly attractive as industrial energy sources. Use of biodiesel and the formulation of a project for undertaking 13.4 million ha of Jatropha plantations in India highlight the seriousness with which the Government of India is promoting carbon neutral energy plantations. The cost of establishment of plantations primarily for fuel production and its conversion to energy are major deterrents in this pursuit. Some of the issues in developing countries, like low productivity on marginal lands, degraded forest lands, and unorganized units for biomass energy conversion, result in cost escalation as compared to other energy sources. This paper revisits the scope for raising energy plantations, a comparison of the direct and indirect mitigation potential uses of plantations as an adaptation strategy through reforestation and afforestation projects for climate change mitigation and socio-economic issues to make this venture feasible in developing countries.