few days ago, the Philippine Department of Energy (DOE) said that it would soon conduct a study that would look into the imposition of additional excise taxes on fuel and how that would impact the country's consumers.

At present, the government levies a tax of PHP4.35 per liter on unleaded gasoline and PHP5.35 per liter on leaded gasoline. And although the country uses almost twice as much diesel fuel compared to gasoline (9.34 billion liters for diesel versus 5.22 billion liters for gasoline in 2015), no tax is currently levied on diesel fuel.

Given that the majority of diesel engines found in Philippine vehicles are of the older, more polluting type, it is no wonder that major cites like those in Metro Manila appear as though they are layered with a coating of grime all year round.

Aside from the carbon dioxide (CO2) emitted by gasoline engines, diesel engine tailpipe emissions also contain nitrous oxides (NOx) and particulates made up of sulfur compounds. It is these emissions that make up the dirty brown haze that envelopes many Philippine cities. It is these particulates that affect the very young, the very old, and the more fragile Filipinos who live in highly congested, highly polluted cities all over the Philippines.

There are significant costs directly connected to diesel emissions. The health of millions of Filipinos have been directly compromised by emissions from diesel cars, trucks, and buses—significantly greater than any damage caused by gasoline engines.

The popularity of diesel is in a way understandable. In the Philippines, diesel fuel is cheaper—thanks in part to taxes being levied on gasoline but not on diesel. Secondly, fuel economy on a diesel-powered vehicle is generally better than gasoline-powered vehicles.

The majority of Buses and jeepneys in the Philippines run on diesel and the government has never been able to stand up to their unions who will surely oppose any tax on diesel fuel—not to mention the tens of millions of commuters who eventually will be the ones to bear the brunt of higher diesel prices through increased fares. But at the end of the day, the ongoing damage caused by diesel engine pollution has to be taken in to account and those who use diesel engines have to start paying their fair share of the ills these engines cause.

We Filipinos are top-notch when it comes to dramatics and pointing the finger at developed countries who are big polluters. But truth be told, we do very little to clean up our own back yard. We have done next to nothing to reduce pollution in our air, in our land, in our rivers, and in our seas. And so far, by not taxing diesel fuel we are refusing to recognize the true cost of all the damage it causes.

The question is, will the DOE finally now have the courage to levy a tax on diesel fuel? A tax that should be graduated over a period of years so that eventually diesel fuel will be much more costly than gasoline?