The speaker thinks that

Ok, good afternoon, ladies and gentlemen. In previous weeks we talked about different types of pollution and this week I want to focus on air pollution, with air pollution caused by the car. It’s well known that cars are the main cause of air pollution in cities, which comes up to 60% in some cities and in others even as high as 90% of all air pollution caused by the car. Cars contribute a great deal to the air pollution in our cities, and this will get worse as the number of cars increases in the cities.
    Firstly, I’d like to talk about how cars cause air pollution. How does a car cause air pollution? Well, you are all familiar with the internal combustion engine. There’s a mixture of petrol which explodes and this explosion helps propel a car forwarD．Unfortunately, in this process there are some poisonous chemicals which remain, and these poisonous chemicals mainly come out of the back of the car through the exhaust.
    Now, it’s not just what comes out of the car exhaust that is dangerous, the brakes also cause pollution. The brakes on cars give off asbestos, and as you know asbestos is... is a highly dangerous substance and can kill us.
    And thirdly, the tires themselves give off small rubber particles which are not very good for health. We need to find solutions to this problem. I’m going to talk about 4 possible solutions.
     Firstly, we should try and discourage the use of cars. We could do this by putting higher taxes on petrol or we could make cars more expensive. We could put the price of cars up.
    Secondly, we might encourage alternative methods of transport. For example, recently in Shanghai, you’ve built a subway, which takes some of the pressure off the roads. Some people would use the subway rather than using cars. In addition, we could improve public transport, make it more comfortable, safer, and more regular so that the people will use public transport rather than cars. Next, we could also use cleaner fuels rather than petrol. For example, we might use natural gas in the future or we might experiment with battery group in cars.
    And lastly, we could try mechanical means for reducing the amount of chemicals that are
emitted, which come out of cars, which come out of the exhaust pipe. We could fix things called catalytic converters to exhaust pipes. These are something... these are a device which are fixed over to the exhaust, which controls the carbon monoxide, which reduces the amount of dangerous chemicals that cars give off.
    Now it’s unlikely that any one of these solutions will work on its own. I’m pretty sure that it would take a combination of all four of these solutions to solve the problem.