Drive less to help solve Bangkok's air pollution
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Drive less to help solve Bangkok's air pollution

In this Dec 20 photo, Bangkok, as seen from a condominium in Bangkok's Bang Pho area, is covered with heavy smog. (Photo by Pornprom Satrabhaya)
In this Dec 20 photo, Bangkok, as seen from a condominium in Bangkok's Bang Pho area, is covered with heavy smog. (Photo by Pornprom Satrabhaya)

After a short break from smog due to an abrupt change in the weather pattern, with winds blowing away fine dust particles, known as PM2.5, Bangkok residents are bracing for smog, which will be worse during Christmas and probably New Year. If last year's air problems are a guide, the smog is expected to remain until February.

This year, according to IQAir, air pollution has caused an estimated 9,500 deaths in Bangkok and US$3.7 billion (111.8 billion baht) in damage, such as healthcare and work absences. Clearly, this is a problem that is long overdue to be addressed.

In order to be able to solve the problem, however, we must first understand the multiple causes of Bangkok's awful air pollution. I will focus on PM2.5, fine particles of less than 2.5 micrometres that can dangerously travel deep into people's lungs and even bloodstream. The primary source of PM2.5 in Bangkok comes directly from vehicles in the city and its surrounding areas. Recent studies of how much of the city's PM2.5 total comes from fuel combustion estimate a range from 44% to 73%. The variation is due to the method used, time of year, and location within the city.

Two major causes explain the city's high levels of vehicular air pollution. The first is the sheer number of cars in Bangkok, having risen 250% in the past few decades, jumping from 4.2 million in 1999 to 6.1 million in 2009 and then up to 10.7 million in 2019. The reasons why the number of cars has risen so dramatically are numerous and complex, but the major ones are these: the minimal cost of parking, widespread social pressure to buy and drive cars, poor quality of the bus system, limited coverage of the mass rail system and high costs of using it, and the relatively low costs of purchasing and driving a car. The government has encouraged domestic consumption by making excise taxes lower than the global average. Further, Thailand has low annual registration fees, ranging from $32 to $224 per year whereas Singapore car owners have to pay an annual road tax approximately 10 times higher.

The second major reason for Bangkok's high level of air pollution is the high level of emissions produced by the existing fleet of vehicles. One reason for this is the city's large number of older cars with low fuel efficiency and high pollutant output. The number of cars 10 years or older almost doubled from 2007 to 2019. One incentive for drivers to keep driving older cars is that, in contrast to a number of other countries, Thailand's tax on older vehicles is lower than that on newer ones.

Additionally, many vehicles use diesel engines, which emit significant amounts of PM2.5. Diesel-fuelled vehicles account for approximately one-quarter of the city's registered vehicles. The majority of cars using diesel engines are pickup trucks, accounting for around half of overall sales in the country. Their sales are encouraged by the country's lower-than-average excise taxes. Removing this tax would be politically difficult given this vehicle's widespread popularity.

A related problem is the outdated fuel standards used by the Thai government. Each new Euro standard has more stringent emissions requirements and thus reduces PM2.5 emissions. Thailand has used the Euro 4 fuel standard for small vehicles since 2012 and Euro 3 for large commercial vehicles since 2010.

In contrast, other governments, such as EU members, Hong Kong, and South Korea, already upgraded their emission and fuel standards from Euro 4 to Euro 5, requiring only three years to do so. China did so in four years. The Thai government originally planned to upgrade to Euro 5 standard earlier this year but postponed this until 2023 at the earliest, strangely using Covid-19 as the reason for this delay.

Furthermore, Thailand still has a fledgling electric vehicle market, unlike in Europe, China, and other places. There is limited charging infrastructure and insufficient financial incentives to buy electric vehicles which are much cleaner than other vehicles.

Although the Thai government has recently asked people to drive less, it has not yet passed any comprehensive policy to push people to do so but instead has induced demand by still funding new expressways. One disincentive for car owners to drive their cars is congestion pricing, which has been implemented in a number of cities, including London, Milan and Singapore.

Moreover, those who are responsible for the emissions and those who suffer from them are highly unequal socioeconomically. Those most responsible for causing these emissions are the middle class and rich, who comprise the vast majority of car owners. Many have chosen to move to the suburbs so they can own a house, but this means that they must drive further distances.

Further, according to a senior Bangkok Mass Transit Authority official, if the government enacts any policy, such as more bus lanes or congestion pricing, it fears that "car drivers will mobilise and protest". The poor, in contrast, have a much smaller "pollutant footprint": many drive motorbikes or take the bus. Also, when the government does hold public hearings on public transport, according to a Thailand Development Research Institute official, the government holds them "like a protocol they need to do" but "does not really involve the poor".

However, it is the poor who must bear the brunt of the hazardous effects of air pollution. Next to the roadside, beneath underneath flyovers, and in street canyons between buildings are where concentrations from vehicular exhaust tend to be highest. In Bangkok, informal street vendors, motorbike taxi drivers, and open-air bus riders, who are mostly members of the poor, suffer the highest exposure to pollutants. In contrast, the wealthy have access to better air inside their cars and homes and can better afford expensive air purifiers.

Clearly, policies or schemes are needed to reduce emissions from this sector but also make it more egalitarian. These policies will need to give people greater incentives to drive less by either making it more expensive and inconvenient to drive or more affordable and convenient to use public transport. Improving and prioritising Bangkok's bus system immediately would be a good first step.

Other possible solutions could be creating a low-emissions zone in central districts, promoting electric vehicle usage, and perhaps creating a car allowance rebate system for older cars, which was known in the US as "cash for clunkers".

Danny Marks

Dublin City University Assistant Professor

Danny Marks is an Assistant Professor of Environmental Politics and Policy at Dublin City University.

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