The reduction of old transportation that generates a lot of CO2 might have a slight effect on the reduction of gasses and pollution within a city, nevertheless, it is not enough. It is considerably a small amount of pollution that is generated by cars, businesses and large factories on the other hand are the major pollutants that have to be taken care of. A great example of this is Mexico City. Cars are not allowed to circulate certain day, and yet, this has made no change at all the contingency in the city.

While I disagree that cars are a small part of greenhouse gas emissions, I do believe that businesses and large factories are a large percentage of the problem. Harsher laws should be passed regarding greenhouse gas emissions from factories, yet government corruption and greed on big business's part prevent much from happening.

Laws and regulations have limited the amount of pollution that can be produced by industries, but it is definitely true that they have made seemingly little difference.  With that being said, these regulations were designed to allow less and less pollution as the years go on, slowly easing us out of this pollutant problem.  Though this is a great way to get around the unconcerned industries, it still raises the question of when we will even see the changes and how much longer until we cannot restore the earth to a state closer to its equilibrium due to the damage that is occurring each and every day.

While I agree that factories are a huge part of the problem, I think that decreasing car emissions is still a very good idea for reducing CO2 levels, in today's world any little thing can help