Fossil fuels may have rescued the whales from wholesale slaughter at the turn of last century (before the age of the oil drills most of our oil was cooked from whale blubber) but it won't be around forever. Meanwhile, the cars on our streets are being driven by motorists who have to decide which type of fuel to put in their tanks.
Conventional cars run either on petrol or diesel; these two fuels make slightly different effects on human health and our atmosphere. From a climate-change point of view; diesel seems to be the better choice; diesel cars pump out less greenhouse gases to drive you for the same distance compared to petrol, meaning less carbon dioxide to drive temperatures way up!
That's because diesel engines can be designed for higher fuel efficiency, wasting less oil as well. However, diesel's bad side is it creates more fine post-combustion particles, plus more nitrogen oxide, one of the major elements in urban smog.
Diesel's products are especially hard on the lungs, as fine ash and particulates are related to higher incidences of respiratory ailments. The small particle size means more chemical exposure in the lungs and a longer presence in the air. Diesel's fumes tax the heart harder and can lead to premature deaths; for this it's rated as a more dangerous fuel than petrol by government standards.
Petrol on the other hand makes less noxious gases, but equal diesel when it comes to carcinogens, mucous memebrane and throat irritants and neurotoxins! Petrol's small advantages in preserving our health comes at the expense of larger overall greenhouse gas production.
Our current state of diesel technology has a simple solution, the particulate filter; diesel fumes can be purified of up to 80% of their bad particles before they exit the tailpipe. The good thing is that most car importers in Australia have already fitted in a filter in their cars; however, some high-profile marques haen't done so yet. If you're driving a diesel car, check for a filter before bringing it home. Still, the resulting fumes are still not safe enough under advanced pollution guidelines and what needs to be worked on is a new diesel engine that can burn off particulates as they occur.
Health impact is also a grave consideration in a green car campaign. Car technology doesn't focus on new engine systems alone, it's better off to start paying attention to issues in the here and now. Australia's environmental fragility requires constantly updated policies to keep up with the lowering pollutant tolerance levels set by Europe's motoring standards and some states in the US..