Global Carbon Dioxide Emissions Scenarios: Sensitivity to Social and Technological Factors in Three Regions

Carbon dioxide emissions from 1990 to 2100 AD are decomposed into the product of four factors: population size, affluence (measured here as GDP per capita), energy intensity (energy use per unit GDP) and carbon intensity (carbon dioxide emissions per unit energy). These emissions factors are further subdivided into three regions: more developed countries (MDCs), China, and the remaining less developed countries (LDCs). Departures from a baseline scenario (based on IPCC, 1992a — the so-called ‘business-as-usual’ scenario) are calculated for a variety of alternative assumptions concerning the four emissions factors in the three regions. Although the IPCC scenario is called a ‘non-intervention’ scenario, it is shown, for example, that large decreases in energy intensity in China or carbon intensity in MDCs are built into the ‘business as usual’ case — and such large changes vary considerably from region to region. We show what CO₂ emissions would look like if each of these four emissions factors projected in the baseline case somehow remained constant at 1990 levels. Certain factors like energy intensity improvements and long-term population growth in LDCs, or GDP growth and carbon intensity improvements in MDCs, are shown to have a big contribution to cumulative global emissions to 2100 AD, and consequently, changes in these projected factors will lead to significant deviations from baseline emissions. None of the scenarios examined in this analysis seems to indicate that any one global factor is clearly dominant, but cultural, economic, and political costs or opportunities of altering each factor may differ greatly from country to country.     

Global Carbon Dioxide Emissions Scenarios: Sensitivity to Social and Technological Factors in Three Regions

Carbon dioxide emissions from 1990 to 2100 AD are decomposed into the product of four factors: population size, affluence (measured here as GDP per capita), energy intensity (energy use per unit GDP) and carbon intensity (carbon dioxide emissions per unit energy). These emissions factors are further subdivided into three regions: more developed countries (MDCs), China, and the remaining less developed countries (LDCs). Departures from a baseline scenario (based on IPCC, 1992a — the so-called ‘business-as-usual’ scenario) are calculated for a variety of alternative assumptions concerning the four emissions factors in the three regions. Although the IPCC scenario is called a ‘non-intervention’ scenario, it is shown, for example, that large decreases in energy intensity in China or carbon intensity in MDCs are built into the ‘business as usual’ case — and such large changes vary considerably from region to region. We show what CO₂ emissions would look like if each of these four emissions factors projected in the baseline case somehow remained constant at 1990 levels. Certain factors like energy intensity improvements and long-term population growth in LDCs, or GDP growth and carbon intensity improvements in MDCs, are shown to have a big contribution to cumulative global emissions to 2100 AD, and consequently, changes in these projected factors will lead to significant deviations from baseline emissions. None of the scenarios examined in this analysis seems to indicate that any one global factor is clearly dominant, but cultural, economic, and political costs or opportunities of altering each factor may differ greatly from country to country.     

Sectoral Trends and Driving Forces of Global Energy Use and Greenhouse Gas Emissions

Disaggregation of sectoral energy use and greenhouse gas emissions trends reveals striking differences between sectors and regions of the world. Understanding key driving forces in the energy end-use sectors provides insights for development of projections of future greenhouse gas emissions. This paper examines global and regional historical trends in energy use and carbon emissions in the industrial, buildings, transport, and agriculture sectors. Activity and economic drivers as well as trends in energy and carbon intensity are evaluated. We show that macro-economic indicators, such as GDP, are insufficient for comprehending trends and driving forces at the sectoral level. These indicators need to be supplemented with sector-specific information for a more complete understanding of future energy use and greenhouse gas emissions.     

Greenhouse gas scenarios for Austria: a comparison of different approaches to emission trends

In the present paper, national and externally organized projections of greenhouse gas emissions for Austria were compared to gain insight on the underlying scenario data assumptions. National greenhouse gas emission trends extend until 2030, an assessment of European Union (EU) countries to 2050. In addition, data for 2000–2100 was extracted from the global emission database described by the Representative Concentration Pathways (RCP). By identifying trends in these projections, it was possible to produce (a) a long-term assessment of national scenarios until 2100, (b) an assessment of the ambition level toward national climate strategies, and (c) a standardized method to compare trends across countries. By extracting RCP data, Austrian’s methane, nitrous oxide, and carbon dioxide emissions up to 2100 could be projected for all sources as well as specific sectors. With respect to the RCP scenario emission data, national projections did not seem to employ the mitigation potentials available for the most stringent RCP scenario, RCP2.6. Comparing projections that supported the EU Climate Strategy 2030 with national projections revealed similar trends. Because RCP2.6 is the only scenario consistent with a 2 °C global warming target, and it is much more ambitious than any of the national or European projections, further measures will be required if Austria is to adequately contribute to this widely accepted policy goal.     

Future Trends of Land-Use Emissions of Major Greenhouse Gases

Land-use emissions of greenhouse gases make up over one-third of current total anthropogenic emissions of greenhouse gases and about three-quarters of the total anthropogenic emissions of CH4 and N2O. Considering their contribution to global emissions, it is important to understand their future trends in order to anticipate and mitigate climate change. This paper reviews published scenarios of major categories of these emissions with the aim to provide background information for the development of new scenarios. These categories include CO2 from deforestation, CH4 from rice cultivation, CH4 from enteric fermentation of cattle, and N2O from fertilizer application. Base year estimates of all these categories varied greatly from reference to reference, and hence emissions of all scenarios were normalized relative to their 1990 value before being compared to one another. The range of published scenarios of CO2 emissions from deforestation is widest around the middle of the 21st century and then all scenarios converge to low values towards 2100. By contrast, the different scenarios of CH4 and N2O diverge with time, showing their widest range in 2100. Global emissions of CH4 from rice cultivation vary by a factor of three in 2100 and N2O from fertilized soils by a factor of 2.3. Emissions of CH4 from enteric fermentation of animals have the smallest range (factor of 2.0). The typical long-range trends of land-use emission scenarios vary greatly from region to region - they stabilize in industrialized regions after a few decades, but tend to stabilize later in developing regions or continue to grow throughout the 21st century. To improve the realism of the estimates of future trends of land-use emissions, it is especially important to improve the estimation of the future extent of agricultural land and the rate of deforestation, while taking into account significant driving forces such as the demand for agricultural commodities and crop yields.     

中国铝生命周期能耗与碳排放的情景分析及减排对策

铝工业是高能耗高排放工业,探索铝工业的节能减排路径有助于我国实现《巴黎协定》中的温室气体减排承诺.采用物质流分析和生命周期评价方法,基于存量水平、技术水平和能源结构设置了15种情景,研究了我国铝工业1990～2100年的能耗和碳排放量,探索不同路径下的节能减排潜力.我国铝在用存量将在2040～2050年达到峰值(4.6...     

A Greenhouse Gas Balance of two Existing International Biomass Import Chains

Various utility companies are considering or already initiated the import of biomass from abroad for electricity generation, especially via co-firing in coal-fired power plants. This results in international logistic biomass supply chains, which raise questions on the environmental performance of such chains. In this study, a life cycle inventory has been performed on two existing biomass import chains to evaluate the greenhouse gas balance of biomass import for co-firing. We considered production, transport and co-firing of wood pellets from Canada and palm kernel shells from Malaysia in a 600 MW _e coal-fired power plant in the Netherlands. Those chains are compared with various reference systems for energy production and the alternative use of biomass. Primary energy savings of these import and co-firing chains are between 70% and 100% of the biomass energy content. Net avoided greenhouse gas emissions are in the range of 340–2100 g/kWh. In the most optimistic scenario, pellet co-firing avoids methane emissions that would have occurred if the pellets were decomposed at landfills when not applied for energy production. In the most pessimistic scenario, palm kernel shell co-firing competes with the application as resource for animal feed production, which requires production and transport of an alternative resource. As the energy reference systems of the importing and exporting country and the alternative application of biomass have a significant impact on the net avoided greenhouse gas emissions, these factors should be considered explicitly when studying biomass trade for energy purposes.     

A Review of Global and Regional Sulfur Emission Scenarios

The paper reviews base year emission inventories, driving forces, and long-term scenarios of sulfur emissions as background material for developing a new set of IPCC emissions scenarios. The paper concludes that future sulfur emission trends will be spatially heterogeneous (decline in OECD countries, rapid increase particularly in Asia) and therefore cannot be modeled at a global scale only. In view of ecosystems and food production impacts future sulfur emissions will need to be increasingly controlled also outside OECD countries. As a result, future sulfur emissions are likely to remain significantly below the values projected in the previous IPCC IS92 high emissions scenarios.     

The economics of greening Romania’s energy supply system

Despite the declining trends in total energy consumption, greenhouse gas emissions, energy intensity, and emission intensity over the past two decades, Romania still emits more greenhouse gas per unit of output than many other members of the European Union. The country is looking for further greening of its energy supply system to achieve the clean energy and climate change mitigation goals included in the European Union’s 2030 target and 2050 Roadmap. Using an energy supply optimization model, TIMES, this study develops energy supply mixes for Romania under a baseline scenario that satisfies the European Union’s current energy and climate targets for 2020, a green scenario that satisfies the European Union’s 2030 energy and climate targets, and a super green scenario that satisfies the European Union’s prospective 2050 energy road map. The study finds that although Romania could achieve the green scenario at a moderate cost, it would be challenging and costly to achieve the super green scenario.     

No-policy greenhouse gas emission scenarios: revisiting IPCC 1992

A new set of no-policy global greenhouse gas (GHG) emission scenarios was developed using the atmospheric stabilization framework, the same modeling tool that was used to generate the IS92 emission scenarios for the Intergovernmental Panel on Climate Change. Revised assumptions about population and economic growth, combined with updated information on changes in renewable energy supply, the efficiency of energy generation and other factors resulted in changes in GHG emission profiles over the next century, which led to an increase in the estimated global average temperature change as compared to the IS92 scenarios. Model results indicate that the largest increase in emissions, which led to a temperature increase of about 3.4°C by 2100 (relative to 1990), can be expected when a rapid increase in the GNP per capita levels of the non-OECD countries is combined with a low availability of solar/wind and biomass energy resources and slow energy efficiency improvements. The smallest increase in emissions and temperature by 2100 (about 2.5°C) occurred when a relatively slow increase in the GNP per capita in the non-OECD countries was combined with a high availability of renewable energy resources and rapid energy efficiency improvements.     

Future Greenhouse Gas and Local Pollutant Emissions for India: Policy Links and Disjoints

This paper estimates the future greenhousegas (GHG) and local pollutant emissions forIndia under various scenarios. Thereference scenario assumes continuation ofthe current official policies of the Indiangovernment and forecasts of macro-economic,demographic and energy sector indicators.Other scenarios analyzed are the economicgrowth scenarios (high and low), carbonmitigation scenario, sulfur mitigationscenario and frozen (development) scenario.The main insight is that GHG and localpollutant emissions from India, althoughconnected, do not move in synchronizationin future and have a disjoint under variousscenarios. GHG emissions continue to risewhile local pollutant emissions decreaseafter some years. GHG emission mitigationtherefore would have to be pursued for itsown sake in India. National energy securityconcerns also favor this conclusion sincecoal is the abundant national resource whilemost of the natural gas has to be imported.The analysis of contributing factors tothis disjoint indicates that sulfurreduction in petroleum oil products andpenetration of flue gas desulfurisationtechnologies are the two main contributorsfor sulfur dioxide (SO₂) mitigation.The reduction in particulate emissions ismainly due to enforcing electro-staticprecipitator efficiency norms in industrialunits, with cleaner fuels and vehicles alsocontributing substantially. These policytrends are already visible in India.Another insight is that high economicgrowth is better than lower growth tomitigate local pollution as lack ofinvestible resources limits investments incleaner environmental measures. Ouranalysis also validates the environmentalKuznets' curve for India as SO₂emissions peak around per capita GDP ofUS$ 5,300–5,400 (PPP basis) under variouseconomic growth scenarios.     

Long-term reduction potential of non-CO2 greenhouse gases

A methodology is presented here to assess the potential long-term contribution of non-CO₂ greenhouse gases in mitigation scenarios. The analysis shows the future development of the mitigation potential of non-CO₂ gases (as a function of changes in technology and implementation barriers) to represent a crucial parameter for the overall costs of mitigation scenarios. The recently developed marginal abatement cost curves for 2010 in the EMF-21 project are taken as the starting point. First-order estimates were made of the future maximum attainable reduction potentials and costs on the basis of available literature. The set of MAC curves developed was used in a multi-gas analysis for stabilising greenhouse gas concentrations at 550 ppm CO₂-equivalent. Including future development for the non-CO₂ mitigation options not only increases their mitigation potential but also lowers the overall costs compared to situations where no development is assumed (3–21% lower in 2050 and 4–26% lower in 2100 in our analysis). Along with the fluorinated gases, energy-related methane emissions make up the largest share in total non-CO₂ abatement potential as they represent a large emission source and have a large potential for reduction (towards 90% compared to baseline in 2100). Most methane and nitrous oxide emissions from landuse-related sources are less simple to abate, with an estimated abatement potential in 2100 of around 60% and 40%, respectively.     

LCA of comprehensive pig manure management incorporating integrated technology systems

Increased and intensified pig production has raised the needs for proper management systems of pig manure in order to reduce negative environmental impacts. The objectives of this study were to identify the most significant environmental impacts from pig manure management considering a wide range of impact categories and to determine which integrated technology system at which handling stage can achieve the highest impact reduction. Twelve scenarios applying various treatment, storage and land application systems were developed and compared. Life cycle assessment (LCA) with the aim of capturing the actual consequences of the considered scenarios was selected as the tool for impact quantification. The most important impact categories in this investigation are global warming (GWP), aquatic eutrophication (AEP), respiratory inorganics (RIP), and terrestrial eutrophication (TEP). The two latter impacts, caused by ammonia emissions, have not been widely considered in most of previous LCA studies on pig manure management. The main keys for the effective impact reduction are the integration of treatment technology systems aiming at energy recovery with high nutrient recovery and control of greenhouse gas, ammonia, and nitrate emissions at every handling stage. For GWP and AEP, the anaerobic digestion-based scenario with natural crust storage achieves the highest impact reduction because of high efficiencies in energy and nutrient recovery with restricted emissions of GHG and nitrate. For RIP and TEP, the incineration and thermal gasification based scenarios and the scenario without a treatment system applying the deep injection method yield the highest impact minimisation due to the lowest ammonia emissions. This study further indicates the need to consider all significant impacts to decide the best management options taking into consideration local conditions.     

Climate change impacts on freshwater recreational fishing in the United States

We estimated the biological and economic impacts of climate change on freshwater fisheries in the United States (U.S.). Changes in stream temperatures, flows, and the spatial extent of suitable thermal habitats for fish guilds were modeled for the coterminous U.S. using a range of projected changes in temperature and precipitation caused by increased greenhouse gases (GHGs). Based on modeled shifts in available thermal habitat for fish guilds, we estimated potential economic impacts associated with changes in freshwater recreational fishing using a national-scale economic model of recreational fishing behavior. In general, the spatial distribution of coldwater fisheries is projected to contract, being replaced by warm/cool water and high-thermally tolerant, lower recreational priority (i.e., “rough”) fisheries. Changes in thermal habitat suitability become more pronounced under higher emissions scenarios and at later time periods. Under the highest GHG emissions scenario, by year 2100 habitat for coldwater fisheries is projected to decline by roughly 50 % and be largely confined to mountainous areas in the western U.S. and very limited areas of New England and the Appalachians. The economic model projects a decline in coldwater fishing days ranging from 1.25 million in 2030 to 6.42 million by 2100 and that the total present value of national economic losses to freshwater recreational fishing from 2009 to 2100 could range from $81 million to $6.4 billion, depending on the emissions scenario and the choice of discount rate.     

中国居民家庭消费碳足迹近20年增长情况及未来趋势研究

近年来,伴随着社会经济的快速发展,我国已成为全球温室气体排放量最大的经济体,而居民消费活动造成的碳排放始终是可持续消费领域的研究热点.本研究综合采用基于投入产出的生命周期评价、结构分解分析、截面分析等方法,并借助EORA数据库,系统研究了近20年中国居民消费碳足迹的总量与组成、驱动因素贡献及未来增长趋势.结果表明,居民消费碳足迹的快速上升通道已经形成,且内在结构演化也呈现规律性,即间接排放和城镇居民排放已占主导地位并且该趋势仍在加强.驱动因素方面,人口增长、城市化进程、消费水平提高是推动碳足迹增长的主要正向力量,同时另外三因素(排放强度、消费结构及经济结构)则构成了延缓碳足迹过快增长的减排力量.截面分析结果显示,未来中国居民消费跨越世界平均水平时其碳排放总量将达到2010年基数的1.45倍,当接近于美国人均消费水平时将达到5.45倍.可以预期,未来我国居民消费碳足迹将会加速增长.     

A global analysis of residential heating and cooling service demand and cost-effective energy consumption under different climate change scenarios up to 2050

Climate change and energy service demand exert influence on each other through temperature change and greenhouse gas emissions. We have consistently evaluated global residential thermal demand and energy consumption up to the year 2050 under different climate change scenarios. We first constructed energy service demand intensity (energy service demand per household) functions for each of three services (space heating, space cooling, and water heating). The space heating and cooling demand in 2050 in the world as a whole become 2.1–2.3 and 3.8–4.5 times higher than the figures for 2010, whose ranges are originated from different global warming scenarios. Cost-effective residential energy consumption to satisfy service demand until 2050 was analyzed keeping consistency among different socio-economic conditions, ambient temperature, and carbon dioxide (CO₂) emission pathways using a global energy assessment model. Building shell improvement and fuel fuel-type transition reduce global final energy consumption for residential thermal heating by 30% in 2050 for a 2 °C target scenario. This study demonstrates that climate change affects residential space heating and cooling demand by regions, and their desirable strategies for cost-effective energy consumption depend on the global perspectives on CO₂ emission reduction. Building shell improvement and energy efficiency improvement and fuel fuel-type transition of end-use technologies are considered to be robust measures for residential thermal demand under uncertain future CO₂ emission pathways.     

气体燃料发动机发展对中国温室气体减排贡献的生命周期分析

为分析气体燃料发动机的温室气体减排能力,应用生命周期分析方法计算了不同燃料的生命周期温室气体排放量,并据此计算了不同发动机的温室气体排放量.建立了气体燃料发动机“最大限度发展”和“不发展”两种情形.据此预测了2020年中国气体燃料发动机的温室气体减排效果,估算了2020年气体燃料发动机的耗气量占气体供应量的比重.结果显示,在最大限度发展情形下,气体燃料发动机将分别为城市公共交通、船舶动力和火力发电领域减少约7.47, 18.25, 450.1Mt CO2e的温室气体,减排量占全国减排目标的5.3%.气体燃料发动机将分别消耗15%的天然气、18.5%的煤层气和50%的垃圾填埋气供应量.考虑我国气体燃料资源结构情况及供应形势,推广气体燃料发动机是切实可行的.     

基于路网车流量的北京城市副中心机动车污染控制情景

应用基于路网车流信息的情景分析方法,对北京城市副中心地区依据不同控制情景,以2015年为基准年建立机动车尾气排放清单.通过计算未来年路网车流信息和各情景下实际路网机动车污染物的排放清单,预测2020年和2025年的污染物排放变化.结果表明,未来10年北京城市副中心路网密度和机动车行驶里程持续增长,与基准情景相比,各控制情景对污染物排放量均有削减,新能源车推广情景对各污染物减排效果显著,且对NOx和PM的减排效果更好.外埠车限行情景对各污染物减排效果均较为显著,淘汰高排放车措施在短时间内削减效果显著,但长期削减效果较弱.综合情景对污染物的削减率达到最佳,机动车污染物CO、NOx、HC和PM排放量分别下降39.0%、58.7%、49.2%和55.5%.     

沈阳市中心城区和市郊区能耗碳排放格局差异

以沈阳市和平区和沈北新区2个不同类型的城区创建国家可持续发展实验区为契机,对比分析了中心城区和市郊区能耗碳排放格局的差异,提出了针对不同区域的特点将碳减排纳入到实验区的可持续发展建设中. 结果表明:中心城区和平区的能耗碳排放格局以原煤、电力和汽油的消耗为主,其中2006─2008年该区燃煤比重逐年下降,汽油比重逐年上升,电力排放总量虽缓慢增加但排放比重却有所下降;而对于郊区沈北新区而言,能耗碳排放格局则以燃煤和电力为主,其中燃煤比重逐年下降,而电力排放逐年上升. 情景预测结果表明: 到2015年和2020年,和平区CO₂排放强度将分别达到1.16和1.11 t/(104元),比2006年分别下降23.2%和26.5%,不能实现2020年单位GDP CO₂排放量比2005年下降40%～45%的减排目标;沈北新区CO₂排放强度下降趋势明显,2015年和2020年将分别达到2.48和2.07 t/(104元),比2006年分别下降63.1%和69.3%,可实现40%～45%的CO₂减排目标. 讨论了中心城区和郊区碳排放格局的差异,并分别给出了适合的碳减排建议.      

考虑车辆类型变化的中国乘用车排放特征

通过引入Lotka-Volterra模型预测了中国未来30年的乘用车竞争趋势;通过引入CHG、VOC、CO、SO₂、PM_2.5、NO_x6类污染物更新了全生命周期清单;并据此建立了政策影响模型和敏感性模型评估电动化、轻量化和清洁化政策情景减排效果.结果表明,乘用车市场的主要竞争力来源于新能源与传统能源的竞争,且纯电动与混合动力乘用车呈S型曲线发展,汽油乘用车占比由92%减少到1%;全生命周期中,纯电动乘用车对CHG、VOC、CO减排效益最优,为20%~85%;汽油与天然气乘用车对SO₂和PM_2.5的减排效益最优,为50.0%;3类情景下税收补贴类政策敏感性最强,CHG、VOC和CO的最优减排情景为电气化情景,PM_2.5、NO_x的最优减排情景为清洁化情景,而SO₂的最优减排情景则为整车轻量化.