Air-sea carbon dioxide equilibrium: Will it be possible to use seaweeds for carbon removal offsets?

To limit global warming below 2°C by 2100, we must drastically reduce greenhouse gas emissions and additionally remove ~100-900 Gt CO2 from the atmosphere (carbon dioxide removal, CDR) to compensate for unavoidable emissions. Seaweeds (marine macroalgae) naturally grow in coastal regions worldwide where they are crucial for primary production and carbon cycling. They are being considered as a biological method for CDR and for use in carbon trading schemes as offsets. To use seaweeds in carbon trading schemes requires verification that seaweed photosynthesis that fixes CO2 into organic carbon results in CDR, along with the safe and secure storage of the carbon removed from the atmosphere for more than 100 years (sequestration). There is much ongoing research into the magnitude of seaweed carbon storage pools (e.g., as living biomass and as particulate and dissolved organic carbon in sediments and the deep ocean), but these pools do not equate to CDR unless the amount of CO2 removed from the atmosphere as a result of seaweed primary production can be quantified and verified. The draw-down of atmospheric CO2 into seawater is via air-sea CO2 equilibrium, which operates on time scales of weeks to years depending upon the ecosystem considered. Here, we explain why quantifying air-sea CO2 equilibrium and linking this process to seaweed carbon storage pools is the critical step needed to verify CDR by discrete seaweed beds and nearshore and open ocean aquaculture systems prior to their use in carbon trading.

Comparing the EU and Chinese carbon trading market operations and their spillover effects.

A carbon trading market (CTM) policy for trading carbon dioxide emission rights as a commodity was created to reduce greenhouse gas emissions. CTMs operate differently in different countries and regions, and their interactions deserve an in-depth study. This study focused on the world's largest CTM, the European Union (EU), and the CTM of China, largest carbon-emitting country. First, we evaluate the liquidity and volatility of the two CTMs. Subsequently, the VAR model is used to explore the mean spillover effect between the two markets and the BEKK-GARCH model is used to explore the volatility spillover effect between the two markets. The study concludes that: (1) The liquidity of China's CTM is better than that of the EU's CTM. (2) Both the EU and Chinese CTMs are unstable, but the volatility of the Chinese CTM is lower than that of the EU CTM. (3) Price changes in the EU and Hubei CTMs have a mutual influence. (4) There are interactions between the market fluctuations of the EU CTM and the Shanghai CTM and those of the EU CTM and the Hubei CTM. The results of this study have implications for the construction and development of CTMs in the EU and China.

Can carbon emission trading policy break China's urban carbon lock-in?

Greenhouse gas emissions from the use of fossil energy are the main drivers of global warming. China's dominant consumption of fossil energy necessitates adjustments in its energy consumption structure to break free from the carbon lock-in (CLI) phenomenon. Market-based environmental regulations, represented by the carbon trading market (CTM), play an important role in achieving the dual carbon goals of China. Using panel data of 270 prefecture-level cities in China from 2005 to 2020, this study applies a difference-in-difference model to identify the effect of CTM on urban CLI, analyze its transmission mechanism, and further examine the impact of urban characteristic heterogeneity on policy effects from multiple perspectives. Results show that the construction of CTM significantly reduces the degree of CLI of pilot cities; (2) CTM mainly affects urban CLI by promoting urban green technology innovation, industrial structure upgrading, and public green behavior; and (3) the inhibitory effect of CTM on CLI is more significant in cities with high carbon price, industrialization, and digital finance levels. The primary paths toward realizing carbon unlocking include optimizing the institutional design for CTM, enhancing the effective promotion and application of low-carbon technologies, cultivating the green awareness of the public, and increasing government investments in energy-saving and emission reduction techniques.

Accelerate Large-Scale Biomass Residue Utilization via Cofiring to Help China Achieve Its 2030 Carbon-Peaking Goals.

Cofiring biomass with coal for power generation is an affordable and ready-to-deploy technology to help reduce carbon emissions and resolve residual biomass. Cofiring has not been widely applied in China primarily because of some practical limitations, i.e., biomass accessibility, technological and economic constraints, and lack of policy support. We identified the benefits of cofiring with consideration of these practical limitations based on Integrated Assessment Models. We found that China produces 1.82 Bts/year of biomass residues, 45% of which is waste. 48% of the unused biomass can be utilized without fiscal intervention and 70% can be utilized with the subsidized Feed-in-Tariffs for biopower and carbon trading. The average Marginal Abatement Cost of cofiring is twice that of China's current carbon price. Cofiring can help China create 153 billion yuan of farmers' income annually and reduce 5.3 Bts of Committed Cumulative Carbon Emissions (CCCEs, 2023-2030), contributing to the needed CCCE mitigations to China's overall sector and the power sector by 32 and 86%, respectively. About 201 GW of coal-fired fleets are not compliant with China's 2030 carbon-peaking goals, and 127 GW can be saved by implementing cofiring, representing 9.6% of the total fleets in 2030.

Assessing the environmental impact of resource recovery from dairy manure.

Manure management is a major contributor to environmental impacts from large-scale dairy production. In this study, technologies for recovering energy, nutrients, and water from dairy manure were evaluated using life cycle assessment (LCA) and compared to conventional practices on California dairy farms. Six scenarios were evaluated: conventional manure management practices, anaerobic digestion (AD) for biogas recovery, and four scenarios for nutrients, energy, and water integrated recovery, called NEWIR. The NEWIR system consists of hydrothermal carbonization (HTC) for energy recovery via hydrochar, algae cultivation in the HTC aqueous product for nutrient recovery and production of protein-rich cattle feed, and water recovery from algae pond effluent via membrane distillation. Four NEWIR scenarios were evaluated, each with a different species of algae. Based on the results of the LCA, AD improves GHG emissions relative to conventional practices by 82%, but has similar eutrophication impacts, posing similar concerns for nutrient management as current practices. Results for the NEWIR system are highly dependent on the algae species used. Three of the four species evaluated (Chlamydomonas reinhardtii, Chlorella vulgaris, and Scenedesmus obliquus) improve GHG emissions by 420-500 kg CO2-eq. per functional unit, while net water consumption is increased by approximately 75% over AD and conventional practices Spirulina maxima requires more water and chemical inputs for cultivation than the other species, resulting in higher water use (21 times higher than baseline), though GHG emissions are still reduced by 85 kg CO2-eq. per functional unit relative to conventional practices. All NEWIR scenarios improve eutrophication impacts relative to AD and conventional practices by 16-46% for marine eutrophication and 18-99% for freshwater eutrophication, depending on the algae species used. The results suggest integrated resource recovery through NEWIR is a promising treatment method for manure to mitigate GHG emissions and improve nutrient management on large-scale farms. In addition, carbon and nutrient trading policies are discussed in relation to resource recovery technologies and their potential to incentivize producers to recover products from dairy manure.

Does geopolitical risk matter in carbon and crude oil markets from a multi-timescale perspective?

The ongoing Russia-Ukraine conflict serves as a prime illustration of geopolitical risk, manifesting implications beyond global energy price surges and regional energy deficits; it also resonates within the carbon trading market. This study delves into the non-linear and asymmetric impacts of geopolitical risk on oil-carbon linkages spanning 2013 to 2022. Commencing with an exploration of dynamic correlations within the carbon and crude oil markets, our findings indicate that market movements in carbon or crude oil are subject not only to their respective historical volatility trends but also to reciprocal influences from the alternate market, highlighting the existence of asymmetric spillovers between the carbon and crude oil markets. Subsequently, a threshold vector error correction model (TVECM) sheds light on the long-term transmission dynamics of geopolitical risk to oil-carbon linkages. It is concluded that the oil-carbon linkages have a limited impact on geopolitical risk and are subject to shocks from geopolitical risk. Finally, the maximum overlap discrete wavelet transform (MODWT) method unveils heterogeneity across temporal scales: in the short term, geopolitical risk fluctuations are influenced by oil-carbon linkages, and in the middle and long run it becomes independent. Such insights furnish investors with an enriched comprehension of the interplay between crude oil and carbon markets amid geopolitical disturbances, while also offering policymakers a foundation upon which to sculpt informed responses to geopolitical risk.

Rethinking personal carbon trading (PCT) mechanism: A comprehensive review.

The implementation of Personal Carbon Trading (PCT) holds promise in facilitating a noteworthy contribution towards the attainment of emissions reduction predicated on consumption patterns and consequently motivating lifestyle modifications. As individual consumption behaviors usually lead to continuous changes in carbon emissions, it is crucial to rethink PCT from a systematic perspective. This review employed a bibliometric analysis of 1423 papers related to PCT, highlighting the key themes of carbon emissions from energy consumption, climate change, and public opinion on policies in the context of PCT. Most of the existing PCT researches focus on theoretical assumptions and public attitudes, while the quantification of carbon emissions and simulation of PCT require further investigation. Furthermore, the concept of Tan Pu Hui is seldom addressed in PCT studies and case analyses. Moreover, there are limited PCT schemes worldwide that can be directly implemented in practice, leading to a scarcity of large-scale, high-participation case studies. To address these gaps, this review proposes a framework to clarify how PCT can stimulate individual emission reductions on the consumption side, comprising two phases, from motivation to behavior and behavior to target. Future endeavors should prioritize the enhancement of the systematic study of the theoretical foundation of PCT, encompassing carbon emissions accounting and policy design, the incorporation of cutting-edge technology, and the reinforcement of integrated policy practice. This review serves as a valuable reference for future research endeavors and policymaking efforts.

Performance evaluation of regulatory schemes for retired electric vehicle battery recycling within dual-recycle channels.

As electric vehicles (EVs) are developing at a rapid pace, the foreseeable "scrap tide" of EV batteries poses a severe challenge to ecological protection. This article investigates a dual-recycle channel closed-loop supply chain and provides regulatory solutions to retired EV batteries' recycling. Specifically, we construct four supervision scenarios: S1 no policy intervention, S2 reward-penalty scheme, S3 deposit-refund scheme, and S4 dual scheme combining S2 and S3. Based on the Stackelberg game and empirical data, all scenarios' recycling performance is evaluated and compared with a view to "society, economy, and environment". The results revealed: (1) Compared with S1, the recycling rate and carbon reduction rate in S2∼S4 increase by 2.6049%/0.0092%, 4.0379%/0.0285%, and 6.6660%/0.0379%, respectively; (2) The difference between S2 and S3 in recycling performance depends on regulatory intensities, yet the latter places greater burdens on consumers and firms. The S4 presents optimal environmental performance but at the expense of socioeconomic development; (3) As regulatory intensity increases, social welfare rises driven by environmental benefits, then falls due to overburdened supply chain profits, consumer surplus, and policy expenditures; (4) Carbon trading prices and EVs' potential market sizes affect regulatory schemes' operations. Our results contribute to policy-making and managerial practices for EV battery recycling.

Choosing the right policy: Factors influencing the preferences of consumption-side personal carbon reduction policies.

With the development of the social economy and the improvement of personal income, the government must consider formulating personal carbon reduction policies to reduce carbon emissions from the consumption side. Therefore, it is valuable to understand the public's preferences for different policies and the factors influencing the willingness of policy support, which can help policy selection and promotion. Using data collected from 2801 college students and a multinomial logit model, this study explores the influence of personal and social factors on preferences for three different personal carbon reduction policies (personal carbon trading, carbon tax, and carbon generalized system of preferences). The results show that individuals with higher levels of affluence, social trust, and social norms prefer personal carbon trading; individuals with higher levels of affluence, self-motivation, and social norms prefer carbon tax; individuals with higher levels of low-carbon behavioral attitudes and social trust prefer carbon generalized system of preferences; and low-carbon responsibility, access to low-carbon information, and social equity are beneficial to all three policies. In addition, this study examined the heterogeneity of individuals with different levels of affluence and low-carbon behavioral attitudes. This study compares the differences in influencing factors of policy preferences, clarifies the effects of various personal and social factors, which can help the government to design consumption-side personal carbon reduction policies in the future, and provide a reference for the promotion of corresponding policies.

The spatial impact of carbon trading on harmonious economic and environmental development: evidence from China.

This research explores the endogenous influence of carbon trading on economic development, the ecological environment, and the coordinated development of both using panel data from 30 Chinese provinces and cities except Tibet from 2007 to 2017. First, we provide environmental production elements to build an economic model based on the endogenous growth model, and then we employ three-dimensional graphics to conduct theoretical derivation in a more accessible and tangible manner. Secondly, we build a comprehensive index of China's coordinated economic and environmental growth in the context of carbon trading and use the coupled coordination model to determine the coordinated coupling degree of each location. Thirdly, the S-DID model is built to investigate the local and geographical implications of carbon trading. The findings demonstrate that the policy has a local impact that is notably favorable on the economic and environmental levels of each Chinese province and the coordinated growth between them. The degree of environmental optimization and the degree of coordinated development between the economy and the environment are two additional areas where the carbon trading mechanism has a strong positive geographical spillover impact. This study adds to the body of knowledge on China's carbon trading system and advances the endogenous growth hypothesis.

A Local Electricity and Carbon Trading Method for Multi-Energy Microgrids Considering Cross-Chain Interaction.

The objective of this paper is to propose a local electricity and carbon trading method for interconnected multi-energy microgrids. A local electricity market and a local carbon market are established, allowing microgrids to trade electricity and carbon allowance within the microgrid network. Specifically, excessive electricity and carbon allowance of a microgrid can be shared with other microgrids that require them. A local electricity trading problem and a local carbon trading problem are formulated for multi-energy microgrids using the Nash bargaining theory. Each Nash bargaining problem can be decomposed into two subproblems, including an energy/carbon scheduling problem and a payment bargaining problem. By solving the subproblems of the Nash bargaining problems, the traded amounts of electricity/carbon allowance between microgrids and the corresponding payments will be determined. In addition, to enable secure information interactions and trading payments, we introduce an electricity blockchain and a carbon blockchain to record the trading data for microgrids. The novelty of the usage of the blockchain technology lies in using a notary mechanism-based cross-chain interaction method to achieve value transfer between blockchains. The simulation results show that the proposed local electricity and carbon trading method has great performance in lowering total payments and carbon emissions for microgrids.

Market incentives, carbon quota allocation and carbon emission reduction: Evidence from China's carbon trading pilot policy.

As a major carbon dioxide-emitting country, China set carbon trading market to reduce enterprise carbon emissions through the rational allocation of carbon quotas among different enterprises and regions. The market has also conducted a preliminary exploration for the country to achieve carbon dioxide emissions peak in 2030 and carbon neutrality in 2060 while actively addressing the challenges of global climate change. This study analysed the emission reduction effect of China's carbon trading pilot policy, especially the role of carbon quota and carbon trading price. The analysis used county-level panel data from 1997 to 2017, regarded the implementation of the carbon trading pilot policy as a quasi-natural experiment, and used the difference-in-differences method. The results showed that, first, the policy implementation not only reduced regional carbon emissions but also inhibited carbon dioxide emissions per capita, with long-term effects. Second, the carbon emission reduction effect brought by the carbon pilot policy showed significant heterogeneous results with the different degrees of regional carbon emissions and environmental supervision. The effect was greater in areas with higher carbon emission density and stronger legal supervision. Third, the difference in carbon quota allocations resulted in different emission reduction effects, among which the historical method had the strongest effect. The carbon quota price and number of enterprises participating carbon trading market were the key factors affecting carbon emission reduction.

Can China's carbon trading policy help achieve Carbon Neutrality? - A study of policy effects from the Five-sphere Integrated Plan perspective.

The carbon trading policy seeks to control carbon emissions by putting a price on carbon emissions and establishing a corresponding carbon market for trading. It is a significant move by China to address climate issues and achieve its Carbon Neutrality target. Therefore, assessing the policy effects of carbon trading is fundamental to its implementation nationwide. Based on the panel data of 30 provinces and cities in China from 2008 to 2018, this paper uses the Synthetic Control Method and Differences-in-Differences method to assess the effects of carbon trading policy on achieving Carbon Neutrality. By measuring the net carbon emissions, this research explores the level of Carbon Neutrality in each region. Based on the Five-sphere Integrated Plan (which covers the economy, politics, culture, social and ecological civilization), this research further verifies the impact paths of carbon trading policy on Carbon Neutrality. The results show that: First, carbon trading policy has a significant and sustainable effect on Carbon Neutrality. Second, from the perspective of the Five-sphere Integrated Plan, the carbon trading policy can help to reduce carbon sources and increase carbon sinks by adjusting the industrial structure, coordinating low-carbon policies, promoting cultural dissemination, increasing green space construction, and reducing energy intensity to achieve Carbon Neutrality. Third, cultural construction plays the most significant role in mediating carbon trading and Carbon Neutrality, followed by political construction.

Effect of Chinese pilots carbon emission trading scheme on enterprises' total factor productivity: The moderating role of government participation and carbon trading market efficiency.

Based on the tightening regulation of carbon emissions, China has launched the pilot carbon emission trading scheme (CETS) since 2013. There is growing empirical evidence of the actual effect of CETS to promote enterprises' productivity which is characterized by total factor productivity (TFP). However, most studies ignored the further analysis of influence mechanisms. This paper aims to explore the impact of CETS on the TFP of enterprises and discuss the mediating role of government participation and carbon trading market efficiency. Using data from A-share listed enterprises from CETS-covered enterprises, this paper employed a combination of the propensity score matching (PSM) and difference-in-differences (DID) strategies and found that the CETS has a statistically significant positive impact on the TFP of enterprises, and the positive effect has been maintained for six years since its inception. The moderation analysis indicated that: (1) two dimensions of government participation in terms of the market incentive and government supervision significantly moderate the positive impact of CETS on TFP of enterprises; (2) two dimensions of carbon trading market efficiency in terms of the market scale and liquidity significantly moderates the positive impact of CETS on TFP of enterprises. In light of Chinese pilots CETS policy, the study highlights the important moderating roles of government participation and high carbon trading market efficiency on enterprise's TFP.

Uncertainty or trust? Political trust, perceived uncertainty and public acceptance of personal carbon trading policy.

Achieving carbon neutrality has become a global consensus, and plenty of measures and policies have been proposed in various industries to obtain this ambitious goal. As an innovative and radical environmental policy tool, personal carbon trading (PCT) policy which aims to reduce carbon emissions from the private consumption sector has aroused the attention. For a new policy tool, public support and acceptance is critical to obtain policy legitimacy and policy implementation. To implement PCT policy smoothly, the current research aims to explore the antecedents of public acceptance. From the emotional reaction perspective, this research mainly evaluated how political trust, perceived uncertainty and associated emotions matter for public acceptance of PCT policy. Based on the survey data, this research revealed that political trust has a direct positive impact on public acceptance of PCT policy. Meanwhile, political trust also has an indirect impact on public acceptance of PCT policy via emotions. Specifically, political trust is positively associated with positive emotions and negatively associated with negative emotions. Positive emotions promote public to accept PCT policy, while negative emotions inhibit public to accept PCT policy. The negative emotions exert a more powerful impact on public acceptance than positive emotions. Additionally, we found that perceived uncertainty exerts a negative effect on public acceptance and negatively regulates the relationship between political trust and public acceptance. That is, perceived uncertainty has a significant substitution effect on political trust. According to the research findings, policy implications to improve public acceptance of PCT policy were explored.

What drives resident acceptance of personal carbon trading policy in China?

Personal carbon trading (PCT) policy has been considered as an innovative and radical environmental policy tool to achieve carbon neutrality in private sector. For a new policy tool, resident acceptance is extremely vital and should be considered first and put in a vital position. The aim of this research is to understand resident acceptance of PCT policy and examine what drives resident acceptance and opposition of PCT policy. Based on a national survey in China, this research analyzed the level of resident acceptance toward PCT policy and its associated driving factors. Results delineated that residents are more likely to accept the piloting of PCT policy in other city and more positive toward the implementation of PCT policy in the next five years, but less likely to accept the piloting of PCT policy in their city and more negative toward the immediate implementation of PCT policy across the country. Furthermore, this research uncovered that residents from different regions and living areas and with different income level have different acceptable level to PCT policy. Additionally, this research found that resident acceptance of PCT policy is significantly affected by PCT knowledge, perceived benefit, perceived cost, perceived policy effectiveness and environmental awareness. However, compared with other factors, environmental awareness plays a limited role in improving resident acceptance of PCT policy. On the basis of research findings, measures to improve resident acceptance of PCT policy were discussed.

The Climate Finance Conundrum.

International climate finance is key to managing overall climate risk with many developing countries' climate plans and actions are conditional on getting the necessary financial support. Unsurprisingly, helping fund poorer countries to address climate change is one of the most contentious subjects in climate politics. This article examines the state of play and offers some suggestions to unblock the impasse.

Has Carbon Emissions Trading Reduced PM2.5 in China?

China today has an urgent need to develop low-carbon policies that also address local air pollution. This study uses a difference-in-differences model to estimate the extent to which China's Emissions Trading Scheme (ETS), which directly addresses CO2 emissions, has also generated cobenefits by reducing PM2.5. Using monthly PM2.5 concentration and weather data for 297 Chinese cities from January 2005 to December 2017, we find that (1) China's ETS has reduced PM2.5 concentrations by 4.8%, and this reduction effect is strongest in summer. The results are confirmed by robustness tests including propensity score matching, mahalanobis distance matching, two placebo tests, and controlling atmospheric policies. (2) The ETS pilots have positive spillovers on neighboring nonpilot cities within 300 km of the pilot cites, especially for those downwind neighboring nonpilot cities, and the ETS's cobenefits are primarily a result of firms adopting abatement activities and adjusting industrial structure. (3) The cobenefits of China's ETS pilots are greater in regions with larger carbon trading volume and higher carbon trading price. (4) The reduction in PM2.5 concentration caused by China's ETS may have avoided 23,363 deaths and saved $41.38 billion annually in GDP.

Planetary good governance after the Paris Agreement: The case for a global greenhouse gas tax.

The Paris Agreement and the subsequent IPCC Global Warming of 1.5 °C report signal a need for greater urgency in achieving carbon emissions reductions. In this paper we make a two stage argument for greater use of carbon taxes and for a global approach to this. First, we argue that current modelling tends to lead to a "facts in waiting" approach to technology, which takes insufficient account of uncertainty. Rather than look to the future, carbon taxes that facilitate social redesign are something we have control over now. Second, we argue that the "trade" in "cap and trade" has been ineffective and carbon trading has served mainly as a distraction. Carbon taxes provide a simpler more flexible and pervasive alternative. We conclude with brief discussion of global context.

Unexpected increases in soil carbon eventually fell in low rainfall farming systems.

Understanding the drivers of soil organic carbon (SOC) change over time and confidence to predict changes in SOC are essential to the development and long-term viability of SOC trading schemes. This study investigated temporal changes in total SOC, total nitrogen (N), and carbon (C) fractions (particulate organic carbon - POC, resistant organic carbon - ROC and humus organic carbon - HOC) over a 16-year period for four contrasting farming systems in a low rainfall environment (424 mm) at Condobolin, Australia. The farming systems were 1) conventional tillage mixed farming (CT); 2) reduced tillage mixed farming (RT); 3) continuous cropping (CC); and 4) perennial pasture (PP). The SOC dynamics were also modelled using APSIM C and N modules, to determine the accuracy of this model. Results are presented in the context of land managers participating in Australian climate change mitigation schemes. There was an increase in SOC for all farming systems over the first 12 years (total organic C, TOC% at 0-10 cm increased from 1.33% to 1.77%), which was predominately in the POC% fraction (POC% at 0-10 cm increased from 0.14% to 0.5%). Between 2012 and 2015, there was a decrease in SOC back to starting levels (TOC = 1.22% POC = 0.12% at 0-10 cm) in all systems. The PP system had higher TOC%, POC% and HOC% levels on average and higher SOC stocks to 30 cm depth at the final measurement in 2015 (PP = 30.43 t C ha-1; cropping systems = 23.71 t C ha-1), compared to the other farming systems. There was a decrease in TN% over time in all farming systems except PP. The average C:N increased from 14.1 in 1999 to 19.7 in 2012, after which time the SOC levels decreased and C:N dropped back to 15.8. The temporal change in SOC was not able to be represented by the AusFarm model. There are three important conclusions for policy development: 1) monitoring temporal changes in SOC over 12 years did not indicate long-term sequestration, required to assure "permanence" in SOC trading (i.e. 25-100 years) due to the susceptibility of POC to degradation; 2) without monitoring SOC in reference land uses (e.g. CT cropping system as a control in this experiment) it is not possible to determine the net carbon sequestration, and therefore the true climate change mitigation value; and 3) modelling SOC using AusFarm/APSIM, does not fully represent the temporal dynamics of SOC in this low rainfall environment.