摘要: |
As the vehicle population in China increases, oil consumption and carbon dioxide (CO{sub 2}) emissions associated with on-road transportation are rising dramatically. During this study, we developed a methodology to project trends in the growth of the vehicle population, oil demand, and CO{sub 2} emissions associated with on-road transportation in China. By using this methodology, we projected--separately--the number of highway vehicles, motorcycles, and rural vehicles in China through 2050. We used three scenarios of highway vehicle growth (high-, mid-, and low-growth) to reflect patterns of motor vehicle growth that have occurred in different parts of the world (i.e., Europe and Asia). All are essentially business-as-usual scenarios in that almost none of the countries we examined has made concerted efforts to manage vehicle growth or to offer serious alternative transportation means to satisfy people's mobility needs. With this caveat, our projections showed that by 2030, China could have more highway vehicles than the United States has today, and by 2035, it could have the largest number of highway vehicles in the world. By 2050, China could have 486-662 million highway vehicles, 44 million motorcycles, and 28 million rural vehicles. These numbers, which assume essentially unmanaged vehicle growth, would result in potentially disastrous effects on the urban infrastructure, resources, and other social and ecological aspects of life in China. We designed three fuel economy scenarios, from conservative to aggressive, on the basis of current policy efforts and expectations of near-future policies in China and in developed countries. It should be noted that these current and near-future policies have not taken into consideration the significant potential for further fuel economy improvements offered by advanced technologies such as electric drive technologies (e.g., hybrid electric vehicles and fuel-cell vehicles). By using vehicle growth projections and potential vehicle fuel economy, we projected that China's on-road vehicles could consume approximately 614-1016 million metric tons of oil per year (12.4-20.6 million barrels per day) and could emit 1.9-3.2 billion metric tons of CO{sub 2} per year in 2050, which will put tremendous pressure on the balance of the Chinese and world oil supply and demand and could have significant implications on climate change. Our analysis shows that, while improvements in vehicle fuel economy are crucial for reducing transportation energy use, containing the growth of the vehicle population could have an even more profound effect on oil use and CO{sub 2} emissions. This benefit is in addition to other societal and environmental benefits--such as reduced congestion, land use, and urban air pollution--that will result from containing vehicle population growth. Developing public transportation systems for personal travel and rail and other modes for freight transportation will be important for containing the growth of motor vehicles in China. Although the population of passenger cars will far exceed that of all truck types in China in the future, our analysis shows that oil use by and CO{sub 2} emissions from the Chinese truck fleet will be far larger than those related to Chinese passenger cars because trucks are very use intensive (more vehicle miles traveled per year) and energy intensive (lower fuel economy). Unfortunately, the potential for improving fuel economy and reducing air pollutant emissions for trucks has not been fully explored; such efforts are needed. Considering the rapid depletion of the world's oil reserve, the heightened global interest in addressing greenhouse gas emissions, and the geopolitical complications of global oil supply and demand, the study results suggest that unmanaged vehicle growth and limited improvements in vehicle fuel efficiency will lead to an unsustainable and unstable transportation system in China. In other words, while our projections do not definitively indicate what will happen in the Chinese transportation sector by 2050, they do demonstrate that by allowing uncontained growth in the number of motor vehicles and pursuing only incremental improvements in fuel economy, China may face severe consequences in terms of oil use and CO{sub 2} emissions. Many argue that China--and, in fact, the world--will not be able to accommodate such uncontained vehicle growth. The potential problems related to transportation energy use and CO{sub 2} emissions in China are, indeed, global problems; solving these problems will require international collaboration. |