Carbon Conundrum

Could the Vehicular Emissions Scheme (VES) lead to a paradox of cleaner cars which are less efficient?

- Christopher Tan

THE new Vehicular Emissions Scheme (VES), which kicks in from January 1, 2018 is clearly more stringent than the Carbon Emissions-based Vehicle Scheme (CEVS). And by virtue of that, it is a superior scheme insofar as improving air quality here is concerned.

But will this goal be at some expense to global warming? This doubt arises because the VES sets a very high bar for nitrogen oxides and particulate matter – pollutants which diesel engines tend to emit more of.

As a result, diesel models are more likely to end up facing tax surcharges. This would be a stark contrast to the current state of affairs, where they enjoy sizeable tax rebates under the CEVS.

So, it would not be a surprise if diesel engines become far less popular from next year. Already, the taxi operators, who have long favoured diesels, have been switching to petrol-electric hybrids in the last 18 months or so.

The thing is, while diesel engines emit more nitrogen oxides and particulate matter, they produce less carbon dioxide than petrol equivalents – in fact, up to 30% less. If diesel models become less viable because of the VES, Singapore’s vehicular carbon footprint could enlarge.

And that in turn may affect the Republic’s commitment to reduce greenhouse gases by 16% by 2020, in accordance to the Paris Agreement.