At least 65 percent of urban areas in 25 major cities are sinking, with some local spots dropping by about two inches a year, new research has shown.

The nation's biggest cities are sinking, according to data from a new study. Known scientifically as land "subsidence," the ...

In a sweeping new study of more than 13,000 urban areas worldwide, researchers have mapped air pollution levels and carbon ...

Everyone knows bad air quality when they breathe it in, but how does it measure and compare across different capital cities?