Yes, I'm all for greening the cities and planting trees. But I wish city officials would first thoroughly consider what trees are appropriate. In Islamabad, Pakistan, for example, paper mulberry trees are the leading cause of pollen allergies. From February until April, the pollen count goes as high as 40000 per m³ causing severe problems for residents with pollen allergies.

The trees are an East Asian species that were planted when the city was built. They produce levels of pollen that experts say are among the highest in the world. "This causes one of the most severe forms of pollen allergies ever documented, due to which many people have died. But unfortunately, there is no system of reporting allergy-related deaths," said Mohammad Osman Yusuf, a prominent Pakistani allergy and asthma specialist.

Isn't that just frustrating? How is it in your city?