The problems of urbanization

More than 50 percent of all the people in the world are now living in cities. The UN says that the urbanization is unstoppable and in the year 2050, more than 70% of all the people will live in such mega-cities. Only 14% of the people will live outside cities and 33% will live in poor countries.

But what are the problems of the urbanization and how can we tackle them?
In my mind the biggest problem is the pollution. The car exhaust, the garbage of the people and the greenhouse gasses. More mega-cities mean more people and more people mean more pollution. I think this problem will be nearly unsolvable.
Another problem is, that the jobs are going to run short, because of the accession of the people in big cities. The people in the rural economy are affected to this too and this will cause political and social problems. A lot of people of rural areas are trying to work in urban areas to send their money back to their families to help them to survive.
The poor people for example from Latin America, Asian and Africa, who can not afford living in these mega-cities, have to live in slums with little sanitation an a bad water supply. Because of this, there are a lot of diseases and children are often dying just because of diarrhea or malaria.
One more problem is that the rural infrastructure is overstrained. The cities grew so fast, that the infrastructure didn’t have the chance to grow with the city and so there are a lot of political and social difficulties. And third world countries don’t even try to go with this, because they have to less resource, to expand their cities.

In my mind, there are no solutions for the problem of the urbanization. Because the development shows that more and more people want to live in such big cities and they are going to live there and you can not constrain them to stay in rural areas.