Climate bonds toward achieving net zero emissions and carbon neutrality:Evidence from machine learning technique

The Conference of the Parties(COP26 and 27)placed significant emphasis on climate financing policies with the objective of achieving net zero emissions and carbon neutrality.However,studies on the implementation of this policy proposition are limited.To address this gap in the literature,this study employs machine learning techniques,specifically natural language processing(NLP),to examine 77 climate bond(CB)policies from 32 countries within the context of climate financing.The findings indicate that“sustainability”and“carbon emissions control”are the most outlined policy objectives in these CB policies.Additionally,the study highlights that most CB funds are invested toward energy projects(i.e.,renewable,clean,and efficient initiatives).However,there has been a notable shift in the allocation of CB funds from climate-friendly energy projects to the construction sector between 2015 and 2019.This shift raises concerns about the potential redirection of funds from climate-focused investments to the real estate industry,potentially leading to the greenwashing of climate funds.Furthermore,policy sentiment analysis revealed that a minority of policies hold skeptical views on climate change,which may negatively influence climate actions.Thus,the findings highlight that the effective implementation of CB policies depends on policy goals,objectives,and sentiments.Finally,this study contributes to the literature by employing NLP techniques to understand policy sentiments in climate financing.

A concept to support the transformation from a linear to circular carbon economy:net zero emissions,resource efficiency and conservation through a coupling of the energy,chemical and waste management sectors

Coal and carbon-containing waste are valuable primary and secondary carbon carriers.In the current dominant linear economy,such carbon resources are generally combusted to produce electricity and heat and as a way to resolve a nation’s waste issue.Not only is this a wastage of precious carbon resources,which can be chemically utilized as raw materials for production of other value-added goods,it is also contrary to international efforts to reduce carbon emissions and increase resource efficiency and conservation.This article presents a concept to support the transformation from a linear‘one-way cradle to grave manufacturing model’toward a circular carbon economy.The development of new and sustainable value chains through the utilization of coal and waste as alternative raw materials for the chemical industry via a coupling of the energy,chemical and waste management sectors offers a viable and future-oriented perspective for closing the carbon cycle.Further benefits also include a lowering of the carbon footprint and increasing resource efficiency and conservation of primary carbon resources.In addition,technological innovations and developments that are necessary to support a successful sector coupling will be identified.To illustrate our concept,a case analysis of domestic coal and waste as alternative feedstock to imported crude oil for chemical production in Germany will be presented.Last but not least,challenges posed by path dependency along technological,institutional and human dimensions in the sociotechnical system for a successful transition toward a circular carbon economy will be discussed.

A review of methane leakage from abandoned oil and gas wells:A case study in Lubbock,Texas,within the Permian Basin

In the pursuit of global net zero carbon emissions and climate change mitigation,ongoing research into sustainable energy sources and emission control is paramount.This review examines methane leakage from abandoned oil and gas(AOG)wells,focusing particularly on Lubbock,a geographic area situated within the larger region known as the Permian Basin in West Texas,United States.The objective is to assess the extent and environmental implications of methane leakage from these wells.The analysis integrates pertinent literature,governmental and industry data,and prior Lubbock reports.Factors affecting methane leakage,including well integrity,geological characteristics,and human activities,are explored.Our research estimates 1781 drilled wells in Lubbock,forming a foundation for targeted assessments and monitoring due to historical drilling trends.The hierarchy of well statuses in Lubbock highlights the prevalence of“active oil wells,”trailed by“plugged and abandoned oil wells”and“inactive oil wells.”Methane leakage potential aligns with these well types,underscoring the importance of strategic monitoring and mitigation.The analysis notes a zenith in“drilled and completed”wells during 1980-1990.While our study's case analysis and literature review reiterate the critical significance of assessing and mitigating methane emissions from AOG wells,it's important to clarify that the research does not directly provide methane leakage data.Instead,it contextualizes the issue's magnitude and emphasizes the well type and status analysis's role in targeted mitigation efforts.In summary,our research deepens our understanding of methane leakage,aiding informed decision-making and policy formulation for environmental preservation.By clarifying well type implications and historical drilling patterns,we aim to contribute to effective strategies in mitigating methane emissions from AOG wells.

Multiple routes toward engineering efficient cyanobacterial photosynthetic biomanufacturing technologies

Developing efficient CO_(2)utilization technologies can alleviate the urgent pressure on energy and the environment.Moreover,these technologies are crucial for achieving the goal of net zero emissions.Microalgae are photoautotrophic microorganisms that are the main sources of primary productivity in the biosphere.Cyanobacteria,the only prokaryotic microalgae,have also been considered as promising chassis for photosynthetic biosynthesis,directly converting solar energy and CO_(2)into various bio-based products.This technological route is called photosynthetic biomanufacturing,and is advantageous to simultaneous carbon fixation and clean production.This review focuses on development mode,application and suggests trends related to the further development of photosynthetic biomanufacturing.With regard to the link between photosynthetic CO_(2)fixation and the production of desired metabolites,we summarized and compared three widely adopted strategies.“Screening to find”,screening a large number of high-quality cyanobacterial resources and analyzing their intracellular metabolites are of significance for screening novel cyanobacterial species with high-value chemicals and properties of industrial relevance.“Engineering to modify”,the emergence and application of synthetic biological tools and metabolic engineering strategies have enhanced the ability to modify different cyanobacterial species to reshape more carbon to flow toward synthetic tailored chemicals.“Stressing to activate”,through special culture conditions and strategies,combined with omics analysis techniques,silent metabolic pathways and functional modules are activated to induce the accumulation of high-value chemicals.This review provides valid and updated information to facilitate the development of photosynthetic biosynthesis route with carbon fixation and clean production,providing specific feasible solutions for net zero emissions.

A theory of carbon currency

We propose a new international monetary system based on carbon currency(the carbon standard)to tackle two pressing externalities in today’s global economic and political context:the dangerous and irreversible effects caused by unconstrained green-house gas emissions and the cost to the rest of the world as a result of the U.S.dollar being the dominated global currency and the U.S.Federal Reserve increasingly implementing monetary policies not aligned with the global common interest.We define carbon currency as standardized carbon-related securities backed up by the right of one unit of carbon emissions.It can be used as a new global reserve currency and functions as an international unit of account.Through the trading of carbon currency,efficient carbon prices are established.By incorporating the cost of carbon emissions into decision making,carbon pricing provides incentives for countries to pursue low-carbon growth,which helps achieve the net zero emissions global goal set under the 2015 Paris Agreement.Under the carbon standard,the external shocks to the international financial system would come from variations of carbon emissions rather than the U.S.monetary policies.As such,monetary authorities’commitment to maintaining stable exchange rates comes together with monetary policies aiming at pursuing low-carbon growth.The new system potentially poses a plausible solution to the classical Mundellian Trilemma because the objectives of maintaining fixed exchange rate and implementing monetary policy become one.Although several hurdles are constraining the launch of carbon currency immediately,the carbon standard poses a feasible international monetary system as the world-wide campaign to achieve carbon neutrality progresses.