I think the biggest environment problem in my country is air pollution.
Yes, I agree. The air here is much more polluted than in my country. Of course, my country is more agricultural and has much less industry.
We have reduced emission of air pollutants in recent years, but cars are still a major source of them. Factories have become cleaner as stricter environment pollution law have been introduced.
The problem is now on a truly global scale. I don't believe that any single country can do anything about it.