• Question: Why is diesel bad for the environment?

    Asked by 576awrq47 to Srinath, Natasha, Nana, Luisa, Gautam, Alex on 11 Mar 2019.
    • Photo: Alexander Allen

      Alexander Allen answered on 11 Mar 2019:

      Let’s go for the most simple part of the answer first which is that diesel is made of oil and chemically oil is just a mixture of carbon and hydrogen atoms. These are sizable molecules with lots of energy stored in chemical bonds. If you heat up this sort of fuel with oxygen the whole molecular structure falls apart in a process known as combustion. All of the carbon and hydrogen reacts with the oxygen giving off Carbon Dioxide and water as by-products and a lot of energy is produced from the reaction. This energy can go towards powering cars or engines.

      The problem is the Carbon dioxide. One or two molecules are not a terrible thing as carbon dioxide is created by all life when it breathes… the problem is we are burning so much fuel that tonnes and tonnes of carbon dioxide is being pumped into the atmosphere and this builds up acting like a blanket that traps heat from the sun. This causes the earth to begin warming and affecting weather systems all over the planet. Some places become too hot for life to live.

      These little changes are still not the worst thing. The worst thing is that with a little bit of heating we begin to melt ice and there are all sorts of things trapped in ice including more carbon dioxide… This means there could be a chain reaction. Warming melts ice which releases carbon dioxide which causes more warming which melts more ice… and suddenly the whole system runs away and our planet becomes so hot it cannot support life…

      Diesels also contain a number of other nasty contaminants. Sulphur and nitrogen can get released into the atmosphere and both cause acid rain which is even more terrible for environments and eco-systems.

      Diesel is something, like all fossil fuels that we should aim to cut down on but we do have such a reliance that we really need to be looking at cleaner alternatives!

    • Photo: Natasha Dowey

      Natasha Dowey answered on 11 Mar 2019:

      A lot of people think carbon dioxide is the main problem with cars. But actually, nitrogen oxide and particulate matter (teeny tiny particles) are big problems for local air quality. Diesel’s an interesting one, because scientist’s thoughts on it have varied a lot. Diesel comes from fossil fuels, just like unleaded petrol. At first diesel engines weren’t great, then car manufacturers started to make clean and quiet diesel engines, that actually produced less carbon dioxide than petrol. So people were encouraged to buy diesel…. BUT- it was fairly recently realised that the big issue with diesel is actually nitrogen oxide (NO2). NO2 is really bad for people who have asthma, particularly people who live in cities. So now, lots of European cities have realised their NO2 levels are too high, and have linked it to people being encouraged to buy diesel cars!! Some governments are even introducing scrappage schemes, trying to encourage people to ditch their diesel, to improve the air quality in cities.

    • Photo: Srinath Kasturirangan

      Srinath Kasturirangan answered on 11 Mar 2019:

      Not just diesel but all fossil fuels are bad for the environment. But particularly talking about why diesel is bad, you should take a trip to Mumbai in India. Sit in your car at an intersection with the windows open, there is a BIG chance a bus will come stand next to you and blow diesel smoke into your face!! If you wear a white shirt, by the end of your trip, it would have turned black with the soot and particulate pollution from these fossil fuel guzzlers. 1 week of continuous exposure to this and you will contract some kind of chronic breathing related illness. So please say NO to Diesel.