Which of these world capitals is located the farthest north?
Washington, D.C., Athens, Greece, Beijing, China, or Tokyo, Japan?
Of these options, Beijing edges out the other capitals at a latitude of almost 40 degrees north.
AZUZ: And while the Chinese capital has grown to become an industrial powerhouse, it`s struggled with the side effect of that -- air pollution.
Dangerous smog is a visible problem in and around Beijing.
A few years ago, the communist nation declared a war on pollution. It has occasionally banned high polluting cars and trucks from driving. It`s put a hold on winter construction projects to try to improve air quality.
Winter is usually the time of highest pollution because the country burns coal to keep heaters powered up. The country set a goal for Beijing and the cities around it to reduce air pollutants by 25 percent by the year`s end.
But the measures to help air quality have hurt the economy. Businesses like glass factories have lost sales as they`ve had to upgrade to cleaner equipment. China`s annual economic growth was more than 10 percent in 2010. It`s now below 7 percent. At times, the government has relaxed the rules to protect jobs.
Analysts say it`s trying to find the balance between keeping the economy growing while keeping pollutants from growing. There`s a growing number of tools that can help.
SUBTITLE: China`s smog-eating tower.
This is the largest smog vacuum cleaner in the world.
Using positive ionization, it sucks up harmful airborne pollution articles. Then releases the newly-purified air.
It can clean 30,000 m3 of air per hour. That`s one football stadium per day.
The tower creates a "bubble" of clean air which is 40 percent to 70 percent cleaner than the rest of the city