Emission scenarios for a global hydrogen economy and the consequences for global air pollution     

Bas van Ruijven  Jean-Francois Lamarque  Detlef P. van Vuuren  Tom Kram  Hans Eerens 《Global Environmental Change》2011,21(3):983-994

Hydrogen is named as possible energy carrier for future energy systems. However, the impact of large-scale hydrogen use on the atmosphere is uncertain. Application of hydrogen in clean fuel cells reduces emissions of air pollutants, but emissions from hydrogen production and leakages of molecular hydrogen could influence atmospheric chemistry. This paper combines a global energy system model and a global atmospheric model to explore the range of impacts of hydrogen on atmospheric chemistry. We found that emissions of molecular hydrogen may range from 0.2 up to 10% (or 25-167 Tg hydrogen/yr) for a global hydrogen energy system. The lower end of this range would in fact be equal to current emissions from fossil fuel combustion. Hydrogen energy use leads to a clear decrease in emissions of carbon monoxide, nitrogen oxides and sulphur dioxide, but large-scale hydrogen production from coal may lead to net increase in emissions of nitrous oxide and volatile organic compound. Compared to a reference scenario, this would lead to positive impacts on surface concentrations of carbon monoxide, nitrogen oxides and ozone. However, if hydrogen leakage would not be minimised it leads to an increase in methane lifetimes and a decrease in stratospheric ozone concentrations.  相似文献   

江苏省未来植被变化对“碳达峰、碳中和”的影响评价          下载免费PDF全文

刘奕宏  张震  陈虹玮  邹嘉南  胡波 《气象与减灾研究》2022,45(1):46-52

在全国推进“碳达峰、碳中和”的政策背景下,包含碳汇的模型研究对指导减排具有重要意义。以江苏省为例,依据1997—2018年的年碳排放量数据建立ARIMA(5,2,0)模型,对2019—2060年的年碳排放量进行预测和估算。结果显示,江苏省年碳排放量在未来40 a内将保持波动上升的趋势。根据江苏省植被类型分布面积和相关植物的光合速率,得到每种植被类型的CO2年吸收总量,进一步分析不同植被变化下的减排方案,评价未来植被变化对“碳达峰、碳中和”的影响。在植被可增加面积有限且仅种植光合速率较大的经济林的条件下：1） 若2030年后CO2排放量保持不变,排放量应控制在2030年的26.94%,植被面积需增加1.078×109 m2才能在2060年顺利实现碳中和。2） 若2030年后每年CO2排放量与预测结果保持一致,2030年开始年排放量在预测结果的基础上减少81.06%,植被面积需增加1.081×109 m2,可在2060年顺利实现碳中和。3） 若2030年以后CO2排放量以2005年排放量为参考进行减排,并且减少到2005年排放量的75%以下时,不需要增加植被面积,也可在2060年顺利实现碳中和。  相似文献   

Closing yield gap is crucial to avoid potential surge in global carbon emissions     

《Global Environmental Change》2020

Global greenhouse gas (GHG) emissions models generally project a downward trend in CO₂ emissions from land use change, assuming significant crop yield improvements. For some crops, however, significant yield gaps persist whilst demand continues to rise. Here we examine the land use change and GHG implications of meeting growing demand for maize. Integrating economic and biophysical models at an unprecedented spatial resolution, we show that CO₂ emissions from land conversion may rise sharply if future yield growth follows historical trends. Our results show that ~4.0 Gt of additional CO₂ would be emitted from ~23 Mha agricultural expansion from 2015 to 2026, under historical yield improvement trends. If yield gaps are closed expeditiously, however, GHG emissions can be reduced to ~1.1 Gt CO₂ during the period. Our results highlight the urgent need to close global yield gaps to minimize agricultural expansion and for continued efforts to constrain agricultural expansion in carbon-rich lands and forests.  相似文献   

二氧化碳排放以及对中国经济的影响     

张雷  Daniel Todd  谢辉  CHEN WENYAN  Wu Yingmei  JIANG Wei 《地理学报(英文版)》2005,15(1)

1IntroductionA seeming anomaly exists in the world today; namely, the fact that China, the second largest energy consumer and greenhouse-gas emitter, is not subject to any emissions reduction target under the Kyoto Protocol's first emission control period…  相似文献   

水泥生产碳排放的产生环节及减排措施     

逄思宇  曹烨 《化工矿产地质》2014,(4):250-254

在工业生产过程中,CO2的大量排放被认为是导致气候变暖的重要因素之一,因此控制和减少CO2排放已成为人类社会面临的紧迫任务。水泥工业是人为排放CO2的重要来源之一,这就意味着水泥工业会在一种不断增加的管理压力下减少CO2的排放量,以应对全球变暖的现状。水泥生产过程中CO2的直接排放和间接排放两大排放途径,直接排放主要包括碳酸盐分解,烧成燃料/非烧成燃料的燃烧。间接排放主要是指电力消耗所产生的CO2。针对碳的排放环节,有效可行的CO2减排措施,例如原料、燃料的替代,熟料化学成分的改变,能源效率的提高等,对我国水泥工业的碳减排提出一些建议和看法。  相似文献   

Mechanisms for linking emissions trading schemes     

《Climate Policy》2013,13(2):169-184

Linking emissions trading schemes has attracted interest as a means of reducing costs and expanding market size and liquidity. A number of studies have explored the compatibility of schemes, although little attention has been devoted to the implementation of links. Most trading schemes provide for unilateral recognition of certified emission reductions (CERs) and occasionally other units. Restrictions on the types of units and the quantity that can be used are common. Unilateral links can be implemented through adoption of a schedule that lists the units accepted together with limits on, and adjustments to, imported units. Only a bilateral link yields the full benefits of linking trading schemes. No bilateral links have been established yet, but the number of schemes interested in such links is growing. Implementing such a link through a binding agreement affords participants considerable certainty. However, it entails cumbersome adoption procedures as well as legal and procedural constraints. Reciprocal unilateral links, possibly accompanied by an informal agreement, are easier to implement and offer more flexibility. Economic benefits will not differ significantly from a bilateral linking agreement.  相似文献   

National GHG emissions reduction pledges and 2°C: comparison of studies     

Niklas Höhne  Christopher Taylor  Ramzi Elias  Michel Den Elzen  Keywan Riahi  Claudine Chen 《Climate Policy》2013,13(3):356-377

This article provides further detail on expected global GHG emission levels in 2020, based on the Emissions Gap Report (United Nations Environment Programme, December 2010), assuming the emission reduction proposals in the Copenhagen Accord and Cancun Agreements are met. Large differences are found in the results of individual groups owing to uncertainties in current and projected emission estimates and in the interpretation of the reduction proposals. Regardless of these uncertainties, the pledges for 2020 are expected to deliver emission levels above those that are consistent with a 2°C limit. This emissions gap could be narrowed through implementing the more stringent conditional pledges, minimizing the use of ‘lenient’ credits from forests and surplus emission units, avoiding double-counting of offsets and implementing measures beyond current pledges. Conversely, emission reduction gains from countries moving from their low to high ambition pledges could be more than offset by the use of ‘lenient’ land use, land-use change and forestry (LULUCF) credits and surplus emissions units, if these were used to the maximum. Laying the groundwork for faster emission reduction rates after 2020 appears to be crucial in any case.  相似文献   

Dynamics of energy sector and GHG emissions in Saudi Arabia     

A. N. Khondaker  Karim Malik  Nahid Hossain  Shaikh Abdur Razzak  Rouf Ahmad Khan 《Climate Policy》2013,13(4):517-541

The energy sector is the main contributor to GHG emissions in Saudi Arabia. The tremendous growth of GHG emissions poses serious challenges for the Kingdom in terms of their reduction targets, and also the mitigation of the associated climate changes. The rising trend of population and urbanization affects the energy demand, which results in a faster rate of increase in GHG emissions. The major energy sector sources that contribute to GHG emissions include the electricity generation, road transport, desalination plants, petroleum refining, petrochemical, cement, iron and steel, and fertilizer industries. In recent years, the energy sector has become the major source, accounting for more than 90% of national CO₂ emissions. Although a substantial amount of research has been conducted on renewable energy resources, a sustainable shift from petroleum resources is yet to be achieved. Public awareness, access to energy-efficient technology, and the development and implementation of a legislative framework, energy pricing policies, and renewable and alternative energy policies are not mature enough to ensure a significant reduction in GHG emissions from the energy sector. An innovative and integrated solution that best serves the Kingdom's long-term needs and exploits potential indigenous, renewable, and alternative energy resources while maintaining its sustainable development stride is essential.

Policy relevance

The main contributor to GHG emissions in Saudi Arabia is the energy sector that accounts for more than 90% of the national CO₂ emissions. Tremendous growth of GHG emissions poses serious challenges for the Kingdom in their reduction and mitigating the associated climate changes. This study examines the changing patterns of different activities associated with energy sector, the pertinent challenges, and the opportunities that promise reduction of GHG emissions while providing national energy and economic security. The importance of achieving timely, sustained, and increasing reductions in GHG emissions means that a combination of policies may be needed. This study points to the long-term importance of making near- and medium-term policy choices on a well-informed, strategic basis. This analytical paper is expected to provide useful information to the national policy makers and other decision makers. It may also contribute to the GHG emission inventories and the climate change negotiations.  相似文献   

Proposing a beneficiary-based shared responsibility approach for calculating national carbon accounts during the post-Kyoto era     

Maria Csutora  Zsófia Vetőné mózner 《Climate Policy》2013,13(5):599-616

Considerable progress has been made in Europe towards cutting GHG emissions during the last decade, but this achievement is partly due to the delocalization of manufacturing industries to emerging countries. Under the United Nations Framework Convention on Climate Change, the current emission accounting method is production-based and cannot fully capture this effect. The use of such a method is clearly unfavourable for emerging countries and could lead to difficulties in engaging them in climate policy negotiations. The consumption-based approach represents the other extreme in apportioning emission responsibilities. This article proposes the beneficiary-based shared responsibility approach, which outperforms previous methods in terms of scientific justification and political acceptability. Consumer countries benefit from enjoying the product itself, while producing countries benefit from the production process, which provides them with employment, government income, and company profit. Thus, emissions related to the material throughput used to produce exported products should be allocated to the final place of consumption. The income of production activities benefits the producer country, so emissions associated with these values should be allocated to them. The main reason for taking this accounting approach is that the responsibility for emissions and the benefits of enjoying a product should not be decoupled.  相似文献   

The impact of administrative transaction costs in the EU emissions trading system     

Peter Heindl 《Climate Policy》2013,13(3):314-329

This article empirically investigates the impact of transaction costs for monitoring, reporting, and verification (MRV) of emissions on companies regulated by the EU Emissions Trading System (EU ETS) in Germany. Based on a unique panel dataset, we investigate if MRV costs are dependent on the amount of annual emissions of regulated companies and if there are differences in transaction costs between economic sectors. The results indicate that administrative costs are dependent on the amount of annual emissions for larger companies, which has implications for the economic efficiency of the EU ETS. The most important finding, however, is that there are significant differences in MRV transaction costs dependent on the type and size of companies. This implies the existence of considerable economies of scale. Overall, the EU ETS could benefit from reforms by means of a push towards upstream regulation as this would likely increase administrative efficiency.

Policy relevance statement

Transaction costs are, among other things, an important aspect of market-based climate policy design. A policy instrument with low transaction costs is preferred over instruments with larger transaction costs under equal conditions. This is occasionally referred to as administrative efficiency, and its importance was acknowledged in directive 2009/29/EC of the European Commission. Thoughtful empirical examination of transaction costs is essential in order to inform about the extent and impact of these costs. This article provides an analysis of transaction costs for monitoring, reporting, and verification (MRV) of emissions in the EU ETS. It is shown that administrative costs will likely have negative effects on the cost efficiency of the EU ETS. However, the most relevant finding is that small companies (<250 employees) or firms emitting small amounts of carbon dioxide per year face far higher average transaction costs compared with larger firms or emitters. Thus, there is a tendency for the EU ETS to cause MRV transaction costs that are disadvantageous for small companies. A regulation that is more upstream-oriented could mitigate this negative effect to some extent. The EU ETS could initiate a reform that is targeted on putting a price on the carbon content of fossil fuels instead of directly regulating emissions in a so-called ‘end-of-the-pipe’ way at the installation level.  相似文献