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41.
42.
2030年前实现碳达峰、2060年前实现碳中和(简称“双碳”)是我国对国际社会的庄严承诺,已被纳入生态文明建设的总体布局。生态系统碳汇是实现“双碳”目标的重要手段,也是林业和草原实现高质量发展的必然要求。国际有关机构对全球森林、草地和湿地生态系统的碳储量和碳循环进行了评估。自1990年以来,附件一国家(指《联合国气候变化框架公约》附件一列出的经济合作发展组织中所有发达国家和经济转型国家)对本国的碳排放和碳汇进行估算,编制了年度温室气体清单; 我国也编制了5次国家温室气体清单。这些工作对我国开展应对气候变化的研究提供了基础。提出了如下建议: 在编制“双碳” 路线图和时间表时,既要考虑我国生态系统碳汇与能源和工业领域碳排放在区域空间分布和时间维度上的差异性,也要考虑生态系统同时所具有的碳汇和碳排放的特殊性; 生态系统碳汇是碳达峰的非选项,是碳中和的必选项; 生态系统碳汇要遵循国家实现“双碳”目标的基本原则,要将生态系统碳汇作为国家生态建设和保护工程的主要目标,提高碳汇计量和监测能力,完善市场和融资机制。  相似文献   
43.
Aviation constitutes about 2.5% of all energy-related CO2 emissions and in addition there are non-CO2 effects. In 2016, the ICAO decided to implement a Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) and in 2017 the EU decided on faster emission reductions in its Emissions Trading System (EU ETS), which since 2012 includes the aviation sector. The effects of these policies on the expected development of air travel emissions from 2017 to 2030 have been analyzed. For the sample country Sweden, the analysis shows that when emissions reductions in other sectors are attributed to the aviation sector as a result of the EU ETS and CORSIA, carbon emissions are expected to reduce by ?0.8% per year (however if non-CO2 emissions are included in the analysis, then emissions will increase). This is much less than what is needed to achieve the 2°C target. Our analysis of potential national aviation policy instruments shows that there are legally feasible options that could mitigate emissions in addition to the EU ETS and CORSIA. Distance-based air passenger taxes are common among EU Member States and through increased ticket prices these taxes can reduce demand for air travel and thus reduce emissions. Tax on jet fuel is an option for domestic aviation and for international aviation if bilateral agreements are concluded. A quota obligation for biofuels is a third option.

Key policy insights
  • Existing international climate policies for aviation will not deliver any major emission reductions.

  • Policymakers who want to significantly push the aviation sector to contribute to meeting the 2°C target need to work towards putting in place tougher international policy instruments in the long term, and simultaneously implement temporary national policy instruments in the near-term.

  • Distance-based air passenger taxes, carbon taxes on jet fuel and quota obligations for biofuels are available national policy options; if they are gradually increased, and harmonized with other countries, they can help to significantly reduce emissions.

  相似文献   
44.
Upon completion, China’s national emissions trading scheme (C-ETS) will be the largest carbon market in the world. Recent research has evaluated China’s seven pilot ETSs launched from 2013 on, and academic literature on design aspects of the C-ETS abounds. Yet little is known about the specific details of the upcoming C-ETS. This article combines currently understood details of China’s national carbon market with lessons learned in the pilot schemes as well as from the academic literature. Our review follows the taxonomy of Emissions Trading in Practice: A Handbook on Design and Implementation (Partnership for Market Readiness & International Carbon Action Partnership. (2016). Retrieved from www.worldbank.org): The 10 categories are: scope, cap, distribution of allowances, use of offsets, temporal flexibility, price predictability, compliance and oversight, stakeholder engagement and capacity building, linking, implementation and improvements.

Key policy insights

  • Accurate emissions data is paramount for both design and implementation, and its availability dictates the scope of the C-ETS.

  • The stakeholder consultative process is critical for effective design, and China is able to build on its extensive experience through the pilot ETSs.

  • Current policies and positions on intensity targets and Clean Development Mechanism (CDM) credits constrain the market design of the C-ETS.

  • Most critical is the nature of the cap. The currently discussed rate-based cap with ex post adjustment is risky. Instead, an absolute, mass-based emissions cap coupled with the conditional use of permits would allow China to maintain flexibility in the carbon market while ensuring a limit on CO2 emissions.

  相似文献   
45.
In principle, many climate policymakers have accepted that large-scale carbon dioxide removal (CDR) is necessary to meet the Paris Agreement’s mitigation targets, but they have avoided proposing by whom CDR might be delivered. Given its role in international climate policy, the European Union (EU) might be expected to lead the way. But among EU climate policymakers so far there is little talk on CDR, let alone action. Here we assess how best to ‘target’ CDR to motivate EU policymakers exploring which CDR target strategy may work best to start dealing with CDR on a meaningful scale. A comprehensive CDR approach would focus on delivering the CDR volumes required from the EU by 2100, approximately at least 50 Gigatonnes (Gt) CO2, according to global model simulations aiming to keep warming below 2°C. A limited CDR approach would focus on an intermediate target to deliver the CDR needed to reach ‘net zero emissions’ (i.e. the gross negative emissions needed to offset residual positive emissions that are too expensive or even impossible to mitigate). We argue that a comprehensive CDR approach may be too intimidating for EU policymakers. A limited CDR approach that only addresses the necessary steps to reach the (intermediate) target of ‘net zero emissions’ is arguably more achievable, since it is a better match to the existing policy paradigm and would allow for a pragmatic phase-in of CDR while avoiding outright resistance by environmental NGOs and the broader public.

Key policy insights

  • Making CDR an integral part of EU climate policy has the potential to significantly reshape the policy landscape.

  • Burden sharing considerations would probably play a major role, with comprehensive CDR prolonging the disparity and tensions between progressives and laggards.

  • Introducing limited CDR in the context of ‘net zero’ pathways would retain a visible primary focus on decarbonization but acknowledge the need for a significant enhancement of removals via ‘natural’ and/or ‘engineered’ sinks.

  • A decarbonization approach that intends to lead to a low level of ‘residual emissions’ (to be tackled by a pragmatic phase-in of CDR) should be the priority of EU climate policy.

  相似文献   
46.
Energy-intensive industries play an important role in low-carbon development, being particularly exposed to climate policies. Concern over possible carbon leakage in this sector poses a major challenge for designing effective carbon pricing instruments (CPI). Different methodologies for assessing carbon leakage exposure are currently used by different jurisdictions, each of them based on different approaches and indicators. This paper aims to analyse the extent to which the use of different methodologies leads to different results in terms of exposure to the risk of carbon leakage, using the Brazilian industry sector as a case study. Results indicate that carbon leakage exposure is an expected outcome of eventual CPI implementation in Brazilian industry. However, results vary according to the chosen methodology, so the definition of the criteria is paramount for assessing sectoral exposure to the risk of carbon leakage.

Key policy insights

  • Despite increasing discussion about the implementation of carbon pricing on the Brazilian industrial sector, the evaluation of carbon leakage risks is still neglected.

  • Assessments of the risk of carbon leakage are directly related to the indicators and criteria used by each methodology. Thus, a given subsector may present different levels of exposure to carbon leakage depending on the methodological choice.

  • More than a purely technical discussion, the methodological definition of carbon leakage risk is a political discussion – it can be well-conducted, leading to the success of a CPI, or even sabotaged, by implicitly subsidizing energy-intensive industries.

  相似文献   
47.
In Malaysia, the main land change process is the establishment of oil palm plantations on logged‐over forests and areas used for shifting cultivation, which is the traditional farming system. While standing carbon stocks of old‐growth forest have been the focus of many studies, this is less the case for Malaysian fallow systems and oil palm plantations. Here, we collate and analyse Malaysian datasets on total carbon stocks for both above‐ and below‐ground biomass. We review the current knowledge on standing carbon stocks of 1) different forest ecosystems, 2) areas subject to shifting cultivation (fallow forests) and 3) oil palm plantations. The forest ecosystems are classified by successional stage and edaphic conditions and represent samples along a forest succession continuum spanning pioneer species in shifting cultivation fallows to climax vegetation in old‐growth forests. Total carbon stocks in tropical forests range from 4 to 384 Mg C/ha, significantly wider than the range of total carbon stocks of oil palm plantations, 2 to 60 Mg C/ha. Conversion of old‐growth forest areas to oil palm plantations leads to substantial reduction in carbon storage, while conversion of forest fallows to oil palm plantations may sustain or even increase the standing carbon stock.  相似文献   
48.
邱灵佳  黄国林  帅琴  苏玉 《岩矿测试》2015,34(2):218-223
有机质与总有机碳(TOC)的换算关系为wo=1.724×wTOC,难以满足当前页岩气开发的现场测定要求,需要作出修正。本文以鄂尔多斯盆地南部页岩样品为研究对象,在传统灼烧法基础上,采用X射线荧光光谱仪测定页岩组成,得出影响烧失量的因素;用热重-差热仪研究页岩灼烧情况,确定了无机盐不分解而有机质分解的最佳灼烧温度和时间。通过线性拟合灼烧法测得的有机质含量与仪器法测得的有机碳含量间的换算关系,建立了一种通过测定烧失量来换算总有机碳含量的新方法。在页岩最佳灼烧温度480℃,灼烧时间1.5 h条件下线性拟合建立了两种新的换算关系,获得TOC测定值与仪器法的标准值相对误差分别为1.691%、0.486%,检出限分别为0.41%、1.60%。综合它们的优缺点,可将测定页岩类样品的换算关系重建为wo=2.125×wTOC。重建的方法通过严格控制灼烧温度,解决了传统灼烧法中烧失量因无机盐高温分解造成有机质代表性不足的问题,可用于精确测定页岩中的有机质或有机碳含量。  相似文献   
49.
Private sector actors are playing an increasingly significant role in the definition and governance of ‘sustainable’ agri-food practices. Yet, to date little attention has been paid by social scientists to how greenhouse gas (GHG) emissions are addressed as part of private agri-food governance arrangements. This paper examines how private actors within agri-food supply chains respond to emerging pressure for measures to reduce GHG emissions from agriculture. Drawing upon the Anglo-Foucauldian governmentality literature, we introduce the notion of the corporate carbon economy to conceptualise the practical techniques that enable private agri-food actors to make GHG emissions thinkable and governable in the context of existing market, regulatory, and supply chain pressures. Using a case study of the Australian dairy industry, we argue that private agri-food actors utilise a range of techniques that enable them to respond to existing government environmental regulations, balance current market pressures with future supply chain requirements, and demonstrate improved eco-efficiency along food supply chains. These techniques – which include environmental self-assessment instruments, tools for measuring GHG emissions, and sustainability reporting – have little direct relevance to the ‘international climate regime’ of carbon trading, and carbon markets more broadly, yet individually and in combination they are crucial in enacting an alternative regime of GHG governance. In concluding, we contend that the growing use of sustainability metrics by international food companies is likely to have the most powerful implications for GHG governance in the agri-food sector, with potentially far-reaching consequences for how future action on climate change is rendered thinkable and practicable.  相似文献   
50.
A large amount of deep oil has been discovered in the Tazhong Uplift, Tarim Basin whereas the oil source is still controversial. An integrated geochemical approach was utilized to unravel the characteristics, origin and alteration of the deep oils. This study showed that the Lower Cambrian oil from well ZS1C (
1x) was featured by small or trace amounts of biomarkers, unusually high concentration of dibenzothiophenes (DBTs), high δ34S of DBTs and high δ13C value of n-alkanes. These suggest a close genetic relationship with the Cambrian source rocks and TSR alteration. On the contrary, the Middle Cambrian oils from well ZS1 (
2a) were characterized by low δ13C of n-alkanes and relatively high δ34S of individual sulfur compounds and a general “V” shape of steranes, indicating a good genetic affinity with the Middle–Upper Ordovician source rocks. The middle Cambrian salt rock separating the oils was suggested to be one of the factors responsible for the differentiation. It was suggested that most of the deep oils in the Tazhong Uplift were mixed source based on biomarkers and carbon isotope, which contain TSR altered oil in varied degree. The percentage of the oils contributed by the Cambrian–Lower Ordovician was in the range of 19–100% (average 57%) controlled by several geological and geochemical events. Significant variations in the δ34S values for individual compounds in the oils were observed suggesting a combination of different extent of TSR and thermal maturation alterations. The unusually high DBTs concentrations in the Tazhong-4 oilfield suggested as a result of mixing with the ZS1C oil (
1x) and Lower Ordovician oils based on δ34S values of DBT. This study will enhance our understanding of both deep and shallow oil sources in the Tazhong Uplift and clarify the formation mechanisms of the unusually high DBTs oils in the region.  相似文献   
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