Rapid Motorization and Vehicular Emission Control in Guangzhou

Introduction: Motorization and Urban Air Quality in Guangzhou

Driven by the advent of rapid motorization in the 1990s, major cities in the Pearl River Delta are increasingly beset with a new type of compound air pollution problem associated with the emission transition process. This pollution mix is characterized by a steady and steep upward trend of vehicular emissions, which is further exacerbated by existing industrial emissions that remain a substantial source of air pollutants in the urban centers. The blend of these pollutants has resulted in regional photochemical smog formation, hence the increase in the number of smoggy days and a subsequent reduction in visibility.

A host of control measures has been implemented since the late 1990s. However, the city government does not wield much leverage in its attempt to reduce vehicular emissions using a science-driven approach. Without a strong direct commitment from those responsible for the pollution to help initiate and adhere to a set of complementary travel demand-oriented measures that will radically reduce current levels of pollution, continued reliance on temporary technical fixes and limited transportation supply capacity are likely outcomes — outcomes expected to further exacerbate urban air quality.

In light of these factors, this case study is divided into three sections. First, the internal factors that drive travel demand are explained in order to bring to light the heavy toll motorization has taken on urban air quality. The second section categorizes a number of vehicular emission control measures. The final section discusses the limitations of Guangzhou's experience with this particular type of pollution control.

Urban Development, Suburbanization, and Rising Vehicle Demand

The main causal factor behind the rise of vehicular emissions in urban areas has been the increase in the demand for car travel in Guangzhou. This upward trend in vehicular emissions points to a variety of practices, including an increase in the number of trips made between destinations, the length of vehicle distance involved in trips, and the number of vehicles involved. A number of secondary factors appear to encourage this demand for increased car travel, including urban development, suburbanization of population, the rise in disposable household income, and the growth of the national automobile industry. At the same time, transportation supply capacity and the availability of alternative transport modes — mainly public transport — have been lagging behind in accommodating the level of demand required by citizens and visitors alike.

Since the 1980s, Guangzhou has been changing its urban configuration rapidly according to its overall urban development plan approved by the State Council in 1982. In 1980, the urbanized area covered 164.9 km² across Liwan and Yuexiu districts, expanding eastward to 259.1 km² in 1995 following development targets set by the government and the Planning Commission of Guangzhou in 1992. The aim was to grow Guangzhou to the standard of an international metropolis within a 15-year period. As of 2006, the urbanized area had grown to 735 km². For the past two decades, the southern and eastern parts of Guangzhou — Panyu district in particular — have been the focus of urban development due to the presence of rich land resources. Panyu district has also been identified as Guangzhou's southern key development site of the 21st century.

Another feature reshaping the urban configuration is the industrial relocation program. Prior to the economic reforms, industries were encouraged to develop in rural areas in order to boost the city's overall economic productivity. However, as rural areas were poorly served by residential accommodations, transport, and other auxiliary infrastructure, many industrial establishments soon relocated back to the urban core. In the early 1980s, partly driven by more structured city land-use planning and improvements in rural transport infrastructure, relocation was conducted in a more systematic manner. Industries that demanded large physical areas, or those responsible for high pollution emissions or transport-intensive operations, were required to relocate to the suburban area. The areas in the urban core previously occupied by these industrial sectors were thus replaced by tertiary sectors encompassing commerce, foreign trade, retailing, and real estate. As a result of this structural relocation process, different industrial economic sectors are today found in the urban core and its periphery.

In addition to changes in industrial distribution patterns, the city has also witnessed a shift in population distribution. The government, alongside industrial growth in the suburban area, placed more emphasis on providing residential accommodations, transportation, and other auxiliary infrastructure at the city fringe. The increase in residential buildings in the suburban area was supported by the burgeoning real estate industry. People began moving further out to take advantage of the newfound affordability and quieter rural lifestyle. This suburban sprawl thus helped disperse a large segment of the population that once lived in the old urban core.

The population in the old urban core has been dropping since the 1980s. From 1980 to 1990, the population in Yuexiu district declined with a negative annual average growth rate of 1.32%. Liwan district recorded a minute annual average growth rate of 0.23% in the same period. However, in districts containing industrial clusters such as Huangpu, the annual average growth rate was 4.8%. From 1990 to 2000, the population in Liwan district continued to decline from 545,482 to 515,009, and Yuexiu from 479,082 to 432,330. During the same period, suburban areas surrounding these two districts — including Haizhu, Tianhe, Baiyun, Huadu, Panyu, and two county-level cities — experienced a surge in population. Such trends continued after the turn of the millennium. Until 2004, all districts except Yuexiu and Liwan continued to experience significant population growth. The population in Yuexiu further dropped to 416,800 in 2004 from 432,330 in 2000, whereas Liwan showed a slight increase from 515,009 to 518,124 during this period.

Immigration and emigration also affected population distribution across districts. From 1999 to 2005, positive net migration rates were recorded in districts surrounding the old urban core. For instance, the highest increase in net migration was recorded in Tianhe, which rose from 25.35% in 1999 to 41.37% in 2005 before declining to 27.17% in 2006 due to a drop in the immigration rate and a rise in the emigration rate. The net migration rate in Panyu showed persistent growth from 6.67% in 1999 to 32.79% in 2006. The net migration rates of the two old districts remained the lowest; Yuexiu reported a 4.09% migration rate in 1999 with Liwan scoring an even lower rate of 2.65%. In the face of suburbanization, these districts continued displaying relatively low net migration rates in 2006 (8.88% in Yuexiu and 5.54% in Liwan), partly attributed to revised administrative consolidation.

Such transformations in both industrial and population distribution patterns have induced demand for more privately owned vehicles. The volume of motor vehicles is on the rise due primarily to population growth within cities, neighboring county residential areas, and districts such as Panyu, Tianhe, Huangpu, Nansha, and Luogang. The pursuit of a better quality of life, made possible by rising disposable income and rapid economic development, further encourages vehicle purchases in Guangzhou. Other Pearl River Delta cities such as Shenzhen and Dongguan have also been experiencing rapid growth within the motor vehicle sector.

One major indicator of this trend is the rate of family car ownership. In particular, ownership is highest among middle- to high-income households. In just two years, the number of family cars per 100 middle-income households jumped from 1.6 to 10.34 between 2004 and 2006, an increase of 87%. In 2002, the rate of ownership in Guangzhou was extremely low at 0.3 per 100 households, whereas Dongguan reached 20 cars per 100 households. By 2007, the rate in Guangzhou still lagged behind Shenzhen (20 per 100 households) and Dongguan (52 per 100 households). However, the rate of increase in Guangzhou was the highest of the three cities: from 2002 to 2007, ownership in Guangzhou grew by 97%, whereas Dongguan recorded a 62% increase.

Within Guangzhou, both high motor vehicle and civilian car ownership are concentrated in urban districts. Since 2001, the share of motor vehicle ownership in urban districts has exceeded 80%. In 2006, the urban districts had 1.5 million motor vehicles, equivalent to 82% of the total number registered in the city (1.83 million). The proportion of private cars to the total number of motor vehicles has consistently exceeded 83% from 2001 to 2006. Private car ownership will continue to increase in tandem with motor vehicle ownership in areas surrounding the old urban core such as Tianhe, Haizhu, Baiyun, Huangpu, as well as in newly developed and peripheral districts including Panyu, Huadu, Zengcheng, and Conghua.

As more people live in districts further from the old urban core, commuting distances have lengthened. Research on commuting patterns in Guangzhou shows that the average commuting distance per capita to travel from home to work doubled from 2.5 km in 1984 to 5.4 km in 1998, and further increased to 6.32 km in 2005. The percentage of people commuting via motorized transportation rose from 25% in 1984 to approximately 51% in 2005 as motorcycles, automobiles, public buses, and taxis became widely available. Although the city has since 1984 increased funding for public transport, the share of public transport usage remains relatively low (less than 25%) compared with developed cities (which range from 40% to 80%). Current development of the public transport system is beset with obstacles such as insufficient network coverage, irregular bus schedules, and inadequate capital on the part of public bus enterprises. These inhibiting factors are further compounded by serious traffic congestion. The current driving speed of public buses has dropped below the international average of 18 km/hour, and during rush hours, car speed decreases further to 15 km/hour in the city center.

Air Pollution Trends: Industrial and Vehicular Emission Patterns

As determinants motivating consumers to acquire private vehicles — rising economic activity, disposable income, and falling vehicle costs — have become more favorable, a new lifestyle has emerged in which more people are accustomed to driving. This huge demand for travel has dramatically transformed air quality in the city, particularly during a period when a fully developed public transport system is yet to materialize. As most manufacturing industries have relocated outside the urban core, air pollution now mainly comes from automobiles, buses, taxis, and freight vehicles competing to occupy a limited physical space. Vehicular pollutants are hard to disperse in the urban core due to dense high-rise buildings. Despite heavy traffic congestion, people continue to drive personal vehicles. As a consequence, the total vehicle kilometers traveled (VKT) has increased rapidly and has led to the early onset of ground-level vehicular emissions.

Historical air pollution control efforts in Guangzhou have been geared towards reducing the two chief industrial air pollutants — SO₂ and total suspended particulates (TSP) — as well as acid rain generated from coal combustion. From the mid-1980s, a series of projects was initiated by the central government and adopted in Guangzhou. Through setting stringent targets on industrial SO₂ emissions, implementing desulfurization programs, and relocating, closing down, or phasing out polluting manufacturing industries, the concentration levels of these pollutants have dropped marginally. Although accepted levels of pollution were within the then Class II National Ambient Air Quality Standards (NAAQSs), emissions remained high compared with WHO guidelines. Meanwhile, NOx emissions showed no signs of abating, as restrictions on industrial NOx emissions were largely neglected at both local and national levels.

In the 1990s, Guangzhou entered a period of high-speed economic development. As the city had been conscientious in implementing industrial emission control measures, annual average SO₂ concentration levels remained relatively stable. In the old urban core districts of Liwan and Yuexiu, which were once subjected to high levels of industrial emissions in the early 1980s, the concentration levels of SO₂ and TSP in 1981 were relatively high, albeit still within the Class II NAAQS guideline. By 1990, largely due to the industrial relocation program, SO₂ concentration levels in Liwan and Yuexiu dropped to 110 µg/m³ and 57 µg/m³ respectively. Similar drops in TSP were not achieved significantly in Yuexiu, where TSP concentration further increased to 224 µg/m³ in 1990.

Any reduction in NOx and CO concentration levels remained virtually absent, as control measures towards traffic source emissions were implemented rather sporadically. The annual average concentration levels of NOx and CO in 1980 were 40 µg/m³ and 168 µg/m³ respectively, but since the mid-1980s both have shown an upward trend. The concentration level of NOx in particular exceeded its Class II NAAQS limit (100 µg/m³) since 1986. By 1996, it had jumped to an alarming 152 µg/m³, well above the revised 1996 Class II NAAQS. Although the concentration level began to decline after 1997, it continued to violate the revised Class II NAAQS guideline. As more citizens chose to live and work in urban districts beyond the old urban core, increased vehicle usage and VKT inevitably drove further NOx increases. NOx emissions, which were insignificant in 1980, jumped to 73 µg/m³ in Liwan and 98 µg/m³ in Yuexiu. Tianhe, Baiyun, and Huangpu districts also recorded surges in NOx concentration levels that violate the Class II NAAQS guideline.