When it comes to air pollution, Krakow in southern Poland is one of the worst cities in Europe. The tens of thousands of coal-burning stoves used by its residents emit so much carbon dioxide that it's often hard to breathe.
Some of the CO2 emissions can be attributed to cars, but coal is seen as being the main culprit. Many Krakowiaks who have to survive on just 200 euros a month heat their homes with coal smuggled out of a mine in nearby Silesia. Krakow's authorities have now banned citizens from using coal for heating, but no one knows how the ban is to be enforced.