The increasing number of vehicles on the roads and the huge import of fossil fuel to power them are coming at a cost to our environment.
Burning a litre of diesel produces about 2.6kg of carbon dioxide (CO2). Annually, on an average a passenger vehicle burns 1,000L of diesel releasing about 2,600kg of CO2 into the atmosphere.
For petrol, burning a litre will approximately emit 2.3kg of co2.
Bhutan may boast to be a carbon neutral country, but until June this year, Bhutan imported about 79,520 kilolitres (kl) of diesel, worth about Nu 3.9 billion (B) and about 24,731kl of petrol, worth Nu 1.1B.
According to trade statistics, the export of electricity was half the import of petroleum products at Nu 5B.
In six months, burning 79,520kl of diesel and 24,731kl of petrol would have released about 182.89 Gigagram (Gg) and 56.88Gg of CO2, respectively.
In general, diesel creates about 15 percent more CO2 a liter than burning petrol.
In 2000, greenhouse gases (GHG) emissions from the transport sector were 118.11Gg of CO2, which accounted for about 20 percent of the country’s total emission.
In a span of 15 years the GHG increased to 240Gg of CO2. Majority of the emission was emitted by heavy-duty vehicles (HDVs), which stood at 135.86Gg followed by passenger cars at 80.39Gg CO2.
Diesel vehicles were responsible for 70 to 90 percent of all local pollutants.
According to records with the Road Safety Transport Authority (RSTA), as of August 31, the country had a total of 104,963 vehicles of which about 20,700 were HDVs including diesel powered large and medium-sized trucks and buses.
According to the low carbon vehicle strategy report, by 2030 the GHG emission is projected to grow threefold (660Gg CO2) based on the annual 15 percent vehicle growth rate and current fuel import trend.
Without a policy intervention, the report stated that severe air pollution issues would arise in the country.
Strategies in place
The National Environment Commission (NEC) has established an emission standard for vehicles in the country since 2010.
The maximum emission levels for petrol vehicles registered prior to 2005 is 4.5 percent of carbon monoxide and 4 percent for vehicles registered after 2005.
For diesel vehicles, smoke density is checked. If the density of smoke emitted by the vehicles registered prior to 2005, is less than 75 Hartridge Smoke Unit (HSU), it is certified as non-polluting.
While for diesel vehicles registered after 2005, the HSU should be less than 70 percent.
An environment official said that emission control for vehicles is a policy to ensure that vehicles remain compliant with original emission standards for which they were certified.
On an average, the lone emission centre in Thimphu conducts emission test for about 1,320 vehicles every month. As of August this year, some 350 vehicles failed the emission test.
Bhutan also has about 105 low carbon (electric) vehicles.
Environmental and Health impact
Bhutan today is faced with increasing air pollutants and GHG emission from transport sector.
As per the World Health Organisation’s (WHO) standard, the concentration of air pollutant (PM-10) is 20 microgram per cubic metre (μg/m3).
However, the vehicle emissions roadmap developed by the NEC in 2017 states that the air quality in Thimphu had PM-10 measuring more than 40 μg/m3 since 2009.
According to an environment official, in urban areas where air pollution is most critical, the major sources of pollutants are passenger cars and HDVs.
Currently Thimphu has about 11,380 HDVs.
Carbon dioxide and Black Carbon emitted from diesel vehicles, is also a major contributor to climate change.
Among several air pollutants identified by the WHO, particulate matter and nitrogen dioxide are the principal pollutants with potential harm to human health in the urban areas.
Exposure to high concentrations of these pollutants can increase respiratory ailments like asthma attacks and bronchitis and cause high blood pressure, heart attack, strokes, and premature death among others.
Children, elderly and the less fortunate are the most vulnerable groups affected by poor air quality.
To reduce vehicular emissions, some of the measures implemented include the establishment of an air quality network, the ban of 2-stroke motorcycles, restricting import of used vehicles, the setting-up of a vehicle emission inspection programme and tax policies favouring electric and hybrid vehicles in the country.
Environment officials said that the transport sector however, requires additional mitigation measures to achieve a sustained reduction of GHG emissions.
Currently, NEC has set up vehicle emission targets and planned policies to maintain minimum emissions from the transport sector.
The targets include lowering the average annual air pollutants levels below WHO guideline by 2025.
As majority of the vehicle imports are from India, complying with the emissions standard of India is crucial, said an official.
India has introduced the BS-IV standard (equivalent to Euro 4) in 2017 and will introduce the BS VI standard (equivalent to Euro 6) by 2020, according to the vehicle emission roadmap.
“By implementing this policy, PM emissions could be lowered as much as 65 percent than in 2015,” the roadmap stated.
NEC’s report recommended using e-taxis, urban buses and hybrid vehicles to address the growing vehicle emission in the country.