新能源汽车外文文献翻译

文献出处：Moriarty P, Honnery D. The prospects for global green car mobility[J]. Journal of Cleaner Production, 2008, 16(16): 1717-1726.原文The prospects for global green car mobilityPatrick Moriarty, Damon HonneryAbstractThe quest for green car mobility faces two major challenges: air pollution from exhaust emissions and global climate change from greenhouse gas emissions. Vehicle air pollution emissions are being successfully tackled in many countries by technical solutions such as low-sulphur fuels, unleaded petrol and three-way catalytic converters. Many researchers advocate a similar approach for overcoming transport's climate change impacts. This study argues that finding a technical solution for this problem is not possible. Instead, the world will have to move to an alternative surface transport system involving far lower levels of motorised travel.Keywords：Green mobility; Fuel efficiency; Alternative fuels; Global climate change; air pollution1. IntroductionProvision of environmentally sustainable (or green) private transport throughout the world faces two main challenges. The first is urban and even regional air pollution, particularly in the rapidly growing cities of the industrialising world. The second is global climate change, caused mainly by rising concentrations of greenhouse gases (GHGs) in the atmosphere. These two barriers to green car mobility differ in several important ways. First, road traffic air pollution problems are more localised, because of the short atmospheric lifetimes of most vehicle pollutants and . Thus regional solutions are often not only possible, but also essential – Australian cities, for example, can (and must) solve their air pollution problems themselves. Matters are very different for global climate change. Except possibly for geo-engineering measuressuch as placing large quantities of sulphate aerosols in the lower stratosphere or erecting huge reflecting mirrors in space, one country cannot solve this problem alone. Climate change is a global problem. Nevertheless, it is possible for some countries to ‘freeload’ if the majority of nations that are important GHG emitter。

Second, there is agreement that air pollution, especially in urban areas, is potentially a serious health hazard, and that road transport can contribute greatly to urban pollutant level. For these reasons, governments in many countries are already taking effective action on air pollution. But until recently, climate change was not recognized as a major problem by some key policy makers, and all countries have yet to take effective action on reducing emissions.Third, vehicular air pollutant problems, at least in the Organisation for Economic Cooperation and Development (OECD) countries, are already showing themselves amenable to various technical solutions, such as low-sulphur fuels, unleaded petrol, and three-way catalytic converters. Some researchers have argued explicitly that global transport emissions can be reduced to very low levels with a combination of two key technical solutions –large improvements in vehicle fuel efficiency and a switch to alternative transport fuels, such as liquid biofuels and hydrogen derived from renewable energy. A much larger group implicitly support this position by projecting large future increases in car numbers and travel and even a globally interconnected highway system.Further, governments throughout the world have endorsed the United Nations Framework Convention on Climate Change (which came into effect in 1994), but at the same time are expanding their road networks, encouraging their car industry, and planning for future car traffic expansion. Overall, the majority of both researchers and policy makers appear to consider that climate change poses no threat to global car mobility. Nevertheless, other researchers argue in general that technology cannot solve the serious environment/resource problems the world faces global warming in particular. Also, the authors themselves have earlier questioned whether the current global transport system can continue on its present course. This paper attempts to resolve these competing claims.Transport, of course, is not the only source of either air pollution or global climate change. All energy-using sectors, and even land-use changes, can contribute to these two problems. It is thus important that any attempts to reduce transport's emissions do not compromise similar efforts in other sectors of the economy. It is also possible that emission reduction policies in one country could adversely affect reduction efforts elsewhere.The aim of this paper is to show that private car travel cannot form the basis for a sustainable global system of surface passenger travel. To simplify the analysis, only GHG emissions will be analysed. We argue that the risk of global climate change requires effective reductions in the next two decades or so, whereas technical solutions to drastically cut car travel's greenhouse gas emissions are only possible in a much longer time frame, and, in some cases, possibly not even then. Overall, the world will have to rely on alternative modes (various forms of public transport, walking and cycling), and, for much of the industrialised world, much-reduced levels of personal travel as well. Of course, it is quite possible that the limited time frame available is also much too short for travel reductions and modal shifts of the magnitude proposed here. The conclusions of this paper have relevance for freight and air transport, and also for other sectors of the economy faced with the need for deep cuts in GHG emissions.2. Global climate change and global car travelThe vast majority of climate scientists support the view that emissions of heat-trapping gases into the atmosphere, particularly CO2, from fossil fuel combustion and land-use changes, cause global warming by altering the earth's radiation balance. The 2007 report from the Intergovernmental Panel on Climate Change (IPCC) states that sea levels are rising, glaciers and sea ice cover are diminishing, and 11 of the 12 warmest years since 1850 have occurred in the 1995–2006 period. Their latest estimate (with a probability of 66% or greater) for climate sensitivity – the equilibrium increase in global temperature resulting from a doubling of CO2 in the atmosphere – is from 2.0 °C to 4.5 °C, with a best estimate of 3.0 °C . Atmospheric CO2 concentrations are currently rising by some two parts permillion (ppm) annually.Moreover, large positive feedback effects could result in emissions, and thus temperatures, rising much more rapidly than expected on the basis of present fuel and land-use emission releases. One such feedback is large-scale methane release from northern tundra as permafrost melts. There is some preliminary evidence that this process is already underway and. Further, studies of past climate have shown that abrupt climatic change can occur over the course of a decade or even a few years and . James Hansen, a prominent US climate scientist, has argued on the basis of paleoclimatic data that if further global warming is not limited to 1 °C beyond the year 2000 value, feedbacks could add to business-as-usual emissions, making the world a ‘different planet’. His 1 °C rise above the year 2000 figure is only slightly below the EU value of 2 °C above the pre-industrial value, given the estimated 0.74 °C warming that has occurred since 1880. He concludes that we can only continue present trends for GHG emissions for another decade or so before committing the climate to irreversible change. Here, we take a position intermediate between den Elzen and Meinshausen and Hansen, and assume that by 2030 global emissions of both CO2 and other GHGs must be reduced to 25% their current value –a four-fold reduction in current global emissions.Thus, to limit dangerous climatic change, annual emissions to the atmosphere of CO2 and other greenhouse gases will need to be greatly curtailed, unless geo-engineering or carbon sequestration techniques can be successfully deployed in time. Equal emissions per capita for all countries, as advocated by ‘contract ion and convergence’ proponents , are likely to be the only acceptable proposal, since it is improbable that industrialising countries such as China or India will permanently accept lower per capita emissions than the already industrialised countries. They could go further, and demand parity in cumulative per capita emissions over the past century for CO2, a long-lived gas. Such an approach would require the already industrialised countries to reduce emissions to near zero. In 2003, global CO2 emissions from fossil fuels averaged 4.2 t/capita, but varied widely from country to country. The US, Australian and Japanese emissions were, respectively, 4.8, 4.3 and2.2 times larger than the world average, implying reduction factors of roughly 19, 17 and 9. (The US reduction value of 19 by 2030 can be compared with Huesemann's calculated value of 66, although his reduction is for 2050.) Although many tropical African countries emitted less than 5% of the average global value, most of the industrialising world would also need to reduce emissions. In the absence of reliable national data, we assume here that other GHG emissions for each country follow the same pattern as fossil fuel CO2 emissions.What are the implications for transport, and private car travel in particular, of these proposed reductions in GHG emissions? Transport contributed an estimated 19% of global GHG emissions in 1971, but 25% in 2006. In 2003, there were roughly 715 million cars in the world (including light commercial vehicles in the US), and 6270 million people, for an average car ownership of 114/1000 persons and . But when considered at the national level, ownership is far from normally distributed. Although the global average is 114/1000 persons, only about 18.5% of the world population lived in countries with between 20 and 200 cars/1000 persons. A further 65% lived in countries with less than 20 cars/1000 (including China and India), and the remaining 16.5% in countries with greater –usually far greater –than 200 cars/1000.Clearly, car ownership is presently heavily polarised; people either live in highly motorised countries – usually in the OECD – or in countries with very low levels of car ownership. But the picture is changing. People in all countries, but particularly those in Asia, want to own a car; indeed, Asia reportedly leads the world in aspirations for car ownership . Where incomes are rising rapidly, as in populous China and India, so too are car sales and ownership. In 2006, China, with sales of 4.1 million, became the world's third largest market for cars, overtaking Germany (3.4 million cars sold). By 2010 it is forecast that China will move into second place ahead of Japan, with only the US ahead. India sold 1.0 million cars in 2006, and annual sales are rising rapidly there as well. Despite urban congestion problems, these countries see vehicle manufacture as an important part of their industrialisation programs, and the major world car companies are investing heavily in new Asian production. In brief, thesecountries and others want to shift their societies from the low to the high motorisation group.What if the whole world moved to the high car ownership group? In the OECD countries, car ownership averages over 450 cars/1000 and , and even in with 500 or more cars/1000, is still growing. In the US, light vehicle ownership at 777/1000 residents in 2004, was 15% larger than the licensed driver population. Global car passenger-km (p-km) in any year is a product of the following three factors: For 2030, the UN median projection for world population is 8.20 billion, and for 2050, 9.08 billion. Assume car ownership per 1000 world population reached an average of 300 in 2030 (which would allow most presently non-motorised countries to attain a basic automobility level of 200 cars/1000 persons), and that the present average p-km/car remains unchanged. World cars would then total 2.46 billion. This projected 2030 value for both total cars and global car p-km is 3.44 times the present world total. Unless fuel efficiency and/or the fuels used change, GHG emissions (and oil consumption) would rise similarly. But, as we have argued, total emissions may well have to be reduced four-fold. Assuming that percentage reductions in car travel emissions must match overall reductions, emissions per car p-km would need to fall about 14-fold by 2030 compared with their present value. The exact value would of course vary from country to country: for the US, Australia and Japan, reduction factors would be 23.6, 22.0 and 8.6, respectively, conservatively assuming no further rise in car numbers in these countries and . Reduction factors would also be high for countries with very low car ownership, but in this case the reductions refer to aspirations, not actual travel or emissions. The next two sections examine whether such reductions are possible in the requisite time frame.3. Greening car mobility: more passenger-km per unit of fuel energyFor GHG emission reductions, the aim is to maximise travel for a given level of CO2-e emissions. Thus, p-km/kg CO2-e is to be maximised for the global car fleet. This ratio in turn can be expanded into the product of the following three factors: This section deals with occupancy rates and fuel efficiency, which together enable personal travel per MJ of fuel to be increased. The following section examinesways of lowering GHG emissions by using alternative fuels, usually with new power systems. In such analyses, it is important to distinguish between, on the one hand, voluntary change, or politically feasible mandated changes under normal conditions, and on the other, changes due to what climatologists in a different context term ‘external forcing’ –for example changes brought about by declining global oil production, or by governments being required to meet serious GHG reduction targets.3.1. Improving occupancy ratesImproving vehicle occupancy has an important advantage: in principle it can be implemented very rapidly with the existing vehicle fleet. The potential efficiency gains are also large. For a typical five-seat car, occupancy rates have effective lower and upper limits of 20% (driver only, equivalent to 1.0 p-km/v-km) and 100% (all seats occupied), respectively, but actual overall values in the highly motorised OECD countries seem to fall in the 25–35% range (1.25–1.75 p-km/v-km).3.2. Improving fuel efficiencyImproving the energy efficiency of cars is often seen as a means of addressing not only greenhouse gas emissions, but also air pollution and global oil depletion/supply security. Two general approaches are possible. The first is to decrease the road load –the sum of rolling, inertial, and air resistance –a general approach that will be needed by all future vehicles, whether private or public transport. Reducing the mass of the vehicle by using lighter weight materials is the most important means of decreasing the road load. The second is to improve the share of input energy that drives the wheels. Electric drive is today regarded as the best approach for achieving this aim, mainly because it enables regenerative braking and eliminates idling.4. Greening car mobility: lower emissions per unit of fuel energyOne way around the difficulty of raising vehicle efficiency is to move away from petroleum-based fuels to fuels with a lower GHG emissions impact. A variety of alternative fuels systems have been advocated for road transport as a way of cutting GHG emissions. These include various biomass-based fuels for internal combustion-engined vehicles, and use of renewable energy to produce hydrogen forfuel cell vehicles or electricity for plug-in hybrids and pure battery electric vehicles. LPG and compressed natural gas are also presently used alternatives to petrol and diesel, but are themselves hydrocarbon fuels in limited supply, and their emission reduction benefits over petrol are minor and . Synthetic fuels made from more abundant coal reserves would double the GHG penalty. Accordingly, this section first looks at biomass-based liquid fuels for existing vehicle types, then at various renewable energy options for alternative propulsion system vehicles.At present, the only transport biofuels produced in quantity are ethanol, chiefly in US and Brazil, but also in an increasing number of other countries, including Australia, and biodiesel, produced mainly in the European Union (EU).The large US and Brazilian ethanol programs are based on corn and sugarcane, respectively, the EU's biodiesel on rapeseed oil. All are food crops, which limit their expansion in a world with unmet food needs, and a still-growing population and . Already, corn prices have risen steeply, as growers can now sell their corn in either the food or fuel markets. Furthermore, at least for grain ethanol, both in the US and in the EU, the fossil fuel energy inputs are, at best, not much below the energy content of the resulting liquid fuel.Initial enthusiasm for pure battery electric vehicles faded when the difficulty of matching the range of internal combustion vehicles became apparent. The new focus is on rechargeable battery hybrid vehicles (often called plug-in hybrids), building on the sales success of hybrid cars and. Plug-in hybrids would normally run off an electric motor powered from rechargeable batteries, but could also run on petrol or other liquid fuels from their small conventional engines, thus extending their range.Car companies in recent years have also shown much interest in hydrogen fuel cell vehicles. But a number of studies have shown that when mains electricity is the primary energy source for both plug-in hybrid vehicles and hydrogen fuel cell vehicles, plug-in hybrids are far more energy-efficient. Specifically, when a given car model is a plug-in battery hybrid vehicle, running off its battery, its well-to-wheels energy efficiency will be up to four times higher than when powered by a hydrogen fuel cell, with the hydrogen produced by electrolysis of water, and . GHG emissionswill follow a similar pattern. Fuel cell vehicles still face many challenges, and infrastructure provision will be expensive. If the hydrogen is produced from natural gas, fuel cell vehicles are slightly more efficient than battery electric vehicles [60]. But the same study projected that in 2020, hybrid gasoline vehicles will be more energy-efficient (in km/MJ) than either battery electric or fuel cell vehicles using NG-derived hydrogen.5. Sustainable and equitable global transportThe preceding sections examined various options for decreasing the GHG emissions per p-km of car travel, and concluded that large reductions could not be expected any time soon. Cutting emissions from freight and air travel are likely to be even more difficult. Not only do both already have far higher loadings than car travel, but also the long service lives of modern aircraft (up to 50 years), limit rapid fleet turnover and .If deep reductions in overall transport GHGs are needed, correspondingly deep reductions in car p-km will be necessary. This section evaluates the travel changes needed, both in high and low car ownership countries.It follows that in most OECD countries, vehicular travel itself will need to be lowered. Fortunately, a surface transport system based on public transport will have much lower overall passenger travel than the one based on private cars, for several reasons:•Private cars, except for some congested inner urban areas, usually allow higher door-to-door speeds than alternative transport modes. Trips that formerly could not be done in a restricted time frame (e.g. work lunch hour) may now be possible, and most trips will have their time costs reduced. Further, in many cases trips cannot be feasibly undertaken at all by alternative modes.•The structure of private motoring costs usually favours high levels of travel, since fixed costs, especially depreciation, registration and insurance, predominate and . Motorists' travel costs per v-km are thus minimised at higher annual levels of vehicle use.•Serving the travel needs of others involves higher levels of passenger travel compared with alternative modes. For example, a parent chauffeuring a child toschool involves two person trips from home to school and one-person trip from school to home. In contrast, travelling by bus involves only one vehicular trip (and walking to school none at all).•Car travel, particularly driving, provides psychological benefits to motorists. To a much greater extent than alternative travel modes, car travel is not solely a derived demand, undertaken to gain access to out-of-home activitie. ‘Going for a drive’ can be the reason for a trip. Additionally, car travel provides protection from the elements, freedom from timetables, privacy, and the ability to carry heavy luggage or shopping purchases, all of which encourage more trip-making than would an alternative transport system.Travel patterns (and the activity patterns which underlie them) of previously highly mobile societies will have to change to accommodate lower vehicular travel levels. Some of the reductions can be compensated by much higher levels of non-motorised travel – walking and cycling. At present, OECD non-motorised travel typically only amounts to about 1 km daily, but it is probable that its value for exercise and weight reduction will receive more emphasis. And although large-scale changes in urban form cannot happen fast, changes at the micro-level can. More use could be made of local shopping, entertainment, and recreation centres, and of those destinations easily accessible by public transport. Travellers could once more get used to combining previously separate vehicular trips. Particularly in the transition to the new system, these changes will be easier for inner city residents, and harder for outer suburban or non-urban residents with less provision for alternative modes. Yet given the entrenchment of the car in western countries, it is difficult to anticipate outcomes from policies to reduce car travel. One way of overcoming this problem is to conduct small-scale social experiments in selected localities (such as for speed reductions, car sharing or parking restrictions) to help understand their impact. If successful, they could be more confidently introduced on a wider-scale.译文全球绿色新能源汽车的发展前景（译文6100字）帕特里克·莫里亚蒂；达蒙·哈尼摘要绿色新能源汽车的发展，面临着两大挑战:废气排放对空气造成的污染和温室气体排放造成的全球气候变化。