More than 500,000 diesel-fueled jeepneys, buses, trucks and other vehicles in Metro Manila are responsible for about 70 percent of the black carbon emissions in the Philippines.These are relics, designed to carry multiple numbers of pasengers. I had a talk with a driver and he explained that this is a difficult job. Often passengers jump off without paying and the driving is, to say the least challenging in the Philippines, hectic and often dangerous.