While international car-free days are thought to effectively reduce the level of air pollution, some other people believe there are alternatives that are also effective. I will discuss both of these views in my essay below.
On the one hand, it is true that exhaust fumes from cars are majorly responsible for polluting the air as they contain a relatively high proportion of pollutants such as CO2. By having some days without cars on the road, no harmful smoke will be released into the atmosphere, and this will therefore improve air quality. This policy is extremely effective in big cities around the world. Take Beijing, the city known for its dirty air and its atmosphere covered with smog, for example. Since this car-free policy was strictly operated, the air quality of the city has greatly improved.
On the other hand, local governments should encourage the use of public tranport like subways because it produces a smaller quantity of pollutants and is less likely to damage the air. Also, the disposal of waste, especially plastic waste that emits toxic fumes if burned carelessly, at landfills should be closely monitored. The final and the most effective way is to use sustainable and environmentally energy sources, for example solar or wind power, to replace fossil fuels in the long term.
In my view, those measures are all effective in addressing the problem of air pollution, but only to a certain extent. Such a problem needs to be dealt with by different approaches and I always feel that if there is only one way being implemented, it will not be enough. 
While international car-free days are  
thought
 to  
effectively
  reduce
 the level of  
air
 pollution,  
some
 other  
people
 believe there are alternatives that are  
also
  effective
. I will discuss both of these views in my essay below.
On the one hand, it is true that exhaust fumes from cars are  
majorly
 responsible for polluting the  
air
 as they contain a  
relatively
 high proportion of pollutants such as CO2. By having  
some
 days without cars on the road, no harmful smoke will  
be released
 into the atmosphere, and this will  
therefore
  improve
  air
 quality. This policy is  
extremely
  effective
 in  
big
 cities around the world. Take Beijing, the city known for its dirty  
air
 and its atmosphere covered with smog,  
for example
. Since this car-free policy was  
strictly
 operated, the  
air
 quality of the city has  
greatly
  improved
. 
On the other hand
, local  
governments
 should encourage the  
use
 of public  
tranport
 like subways  
because
 it produces a smaller quantity of pollutants and is less likely to damage the  
air
.  
Also
, the disposal of waste,  
especially
 plastic waste that emits toxic fumes if burned  
carelessly
, at landfills should be  
closely
 monitored. The final and the most  
effective
 way is to  
use
 sustainable and  
environmentally
 energy sources,  
for example
 solar or wind power, to replace fossil fuels in the long term.
In my view, those measures are all  
effective
 in addressing the problem of  
air
 pollution,  
but
  only
 to a certain extent. Such a problem needs to  
be dealt
 with by  
different
 approaches and I always feel that if there is  
only
 one way  
being implemented
, it will not be  
enough
.