Google Earth's cameras have captured a collection of images which help to illustrate the extent of Beijing's growing pollution problem.
In this series, the haze-covered pictures were taken on 11th January 2013 and the clearer images were taken at the same spot on cleaner days months before.
The search for culprits behind the haze recently turned a spotlight on the country's two largest oil companies and their resistance of tougher fuel standards.
It is thought that many sources contribute to air pollution levels that hit record highs in January, but analysts say the oil companies' conduct underscore a critical challenge facing the country's environment ministry in its mission to curb air pollution.
In January, 33 cities across China had their air quality officially classed as "hazardous".
Authorities were moved to close factories and reduce the fleet of government vehicles.
The pollution also sparked health fears and forced many residents to wear face masks outside. A rise in hospital admissions was also reported.