Technologies, Policies and Measures for Mitigating Climate Change safety and toxicity, and possible performance problems in some climates. The widespread use of hydrogen and electricity in road vehicles poses technical and cost challenges that remain to be overcome. Fossil fuel alternatives to gasoline (e.g., diesel, liquefied petroleum gas (LPG), compressed natural gas (CNG)] can offer 10-30% emission reductions per kilometre, and are already cost-effective for niche markets such as high-mileage and fleet vehicles, including small urban buses and delivery vans (SAR II, 21.3.3.1). Several governments are encouraging the use of LPG and CNG because they have lower emissions of conventional pollutants than gasoline or diesel, but switching from gasoline to diesel can result in higher emissions of particulates and NO,. The use of hybrid and flexiblefuel vehicles may allow alternative fuels and electric vehicles to meet the mobility needs of a larger segment of vehicle users, but at a higher cost and with smaller GHG reductions than single-fuel vehicles (SAR II, 21.3.4). Alternatives to diesel are unlikely to be cost-effective for users of heavy-duty vehicles, and many will result in increased GHG emissions (SAR II, 21.3.3.2). Nevertheless, a small but increasing number of urban buses and delivery vehicles are being fueled with CNG, LPG, or liquid natural gas (LNG) to reduce urban emissions of NO, and particulates. Alternatives to kerosene in aircraft are being tested, but are unlikely to be costeffective in the near term (SAR II, 21.3.3.3). Much of the political impetus for the use of alternative fuels has objectives other than GHG mitigation, such as improving urban air quality, maintaining agricultural employment, and ensuring energy security. Traffic and fleet management systems have the potential to achieve energy savings on the order of 10% or more in urban areas (SAR II, 21.4.2). Energy use for freight transport might be reduced substantially through changes in the management of truck fleets. Modal shifts from road to rail may result in energy savings of 0-50%, often resulting in commensurate or greater GHG emission reductions, especially where trains are powered by electricity from non-fossil fuel sources (SAR II, 21.3.4, 21.4.2). The cost-effectiveness and practicality of freight transport by rail varies widely among regions and commodities (SAR II, 21.2.5). The long-term potential for rail freight may depend on the development of rail and intermodal technologies that can cope with a growing emphasis on flexibility and responsiveness. 23 A first step toward meeting climate objectives in the transport sector is to introduce GHG mitigation measures that are fully justified by other policy objectives. Such measures may increase the competitiveness of industry, promote energy security, improve citizens' quality of life, or protect the environment (SAR II, 21.4). In principle, the most economically efficient way to address all of these issues is by removing the subsidies that exist in some countries for road transport, and by introducing pricing mechanisms that reflect the full social and environmental cost of transport (SAR II, 21.4.5). Long-term management of GHG emissions from light-duty vehicles is likely to depend on implementing wide-ranging strategies involving several areas of policymaking and levels of government (SAR II, 21.4.1). These strategies might involve a variety of measures, including fuel economy standards (SAR II, 21.4.3), fuel taxes (SAR II, 21.4.5.2), incentives for alternative fuel use (SAR II, 21.3.3), measures to reduce vehicle use (SAR II, 21.4.2), and RD&D into vehicle and transport system technology (SAR II, 21.3.6), some of which are evaluated in Table 5. The relative effectiveness of policies depends on national circumstances, including existing institutions and policies, and on underlying technology trends. Measures to reduce GHG emissions from cars are normally appropriate for other lightduty vehicles such as light trucks, vans, minibuses and sports utility vehicles. These vehicle types increasingly are being used as personal vehicles, leading to higher GHG emissions. 24 Technologies, Policies and Measures for Mitigating Climate Change Table 5: Selected examples of measures to mitigate GHG emissions from light-duty vehicles." ⚫GHG effects calculated for 2020 relative to two scenarios: “LOW" (rapid energy intensity reduction, slow traffic growth) and “HIGH" (slow energy intensity reduction, rapid traffic growth), in which emissions roughly correspond to those in IS92c and IS92e, respectively (see Table 4). Ranges in costs and effects of measures reflect differences among literature sources and ranges of uncertainty; scenarios and national differences are explicitly mentioned. *Based on a fuel own-price elasticity of -0.7. Goodwin (1992) suggests a range of -0.7 to −1.0, so effects could be larger than shown here. This increasing use could be encouraged if such vehicles are not subject to the same measures as cars. Many of the measures in Table 5 might be justified wholly or partly by objectives other than GHG mitigation. Fuel economy standards and feebates may be justified as means of overcoming market barriers that inhibit the uptake of cost-effective, energy-efficient technology. Increased fuel taxes also can have a range of social and environmental benefits, while generating revenue that can be recycled to meet priority needs in the transport sector or elsewhere, although they may also impose a welfare loss on some transport users. Governments are most likely to adopt some combination of measures. For example, fuel economy standards and incentives can result in a lower cost of driving-hence more traffic. unless implemented in conjunction with fuel taxes, road pricing, or other measures to discourage driving. Renewable energy supplies are more likely to be able to meet future transport energy needs if energy intensity and traffic levels are kept low. Thus, the effectiveness of incentives to purchase alternativefuel vehicles may be enhanced by taxes on conventional fuels, which provide incentives both to use alternative fuels and to reduce energy use. Policies developed at a local level, aimed at efficiently addressing the full range of local economic, social and environmental priorities, may be among the most important elements of a long-term strategy for GHG mitigation in the transport sector (SAR II, 21.4.2). Measures include computerized traffic control: Technologies, Policies and Measures for Mitigating Climate Change parking restrictions and charges; use of tolls, road pricing and vehicle access restrictions; changing road layouts to reduce traffic speed; and improved facilities and priority in traffic for pedestrians, cyclists, and public transport. Infrastructure development is very expensive, and this cost is likely to be committed for a broad range of economic, social, environmental and other reasons. There may be institutional barriers to integration of GHG mitigation objectives into decision-making processes, but doing so could have a range of benefits, perhaps leading to lower costs where non-motorized transport receives a higher priority than before, relative to motorized transport. Designing cities for non-motorized and public transport can lead to long-term economic benefits as the improved urban environment stimulates local business (SAR II, 21.4.2). Some of the best-known examples of strategies that have succeeded in reducing traffic and its environmental effects, including GHG emissions, have been implemented by the city-state of Singapore, the city of Curitiba in Brazil and a number of European cities (SAR II, 21.4.6). These cities illustrate the importance of local initiative and integrated planning and market-based approaches in developing appropriate combinations of measures. A wide range of environmental and social benefits may come from local transport strategies to reduce traffic and improve non-motorized access (SAR II, 21.4.6), although such strategies may also result in welfare losses for some transport users. In the long term, changes in travel culture and lifestyle, combined with changes in urban layout, might lead to substantial reductions in motorized travel in North American and 27 Table 6 summarizes some possible effects of measures to reduce heavy-duty vehicle GHG emissions. Measures differ from those for light-duty vehicles because trucks vary more than cars in design and purpose, making it harder to design energy-intensity standards for them, although compulsory fitting of speed limiters and power-to-weight ratios can reduce energy use (SAR II, 21.2.4.3). Meanwhile, commercial vehicle operators are relatively responsive to fuel prices in both their management of existing vehicles and their choice of new vehicles. A combination of fuel taxes and voluntary agreements, publicity and incentives (e.g., in license fees) for the purchase of energy-efficient vehicles may be sufficient to encourage the uptake of technology improvements (SAR II, 21.2.4.3). Studies in some countries have found that HDVs are subsidized more than LDVs, considering the high share of road repair costs allocable to HDVs. Efficient measures to reflect these costs to freight operators could increase the costs of road freight by 10-30% (SAR II, 21.4.5) and would achieve 10-30% reductions in freight traffic and associated GHG emissions (based on price elasticities in Oum et al., 1990). Table 6: Selected examples of measures to mitigate GHG emissions from heavy-duty vehicles. |