Air pollution has become so severe, scientists find, that it is adversely affecting storms and weather patterns in other parts of the world.
According to BBC News, researchers have published a new study in the journal Proceedings of the National Academy of Sciences. Delhi, India and Beijing, China are two Asian cities where air pollution is especially severe and they are likely contributing to the formation of storms above the Pacific.
"The effects are quite dramatic," study lead author Yuan Wang, of NASA's Jet Propulsion Laboratory (JPL) at the California Institute of Technology, told BBC News. "The pollution results in thicker and taller clouds and heavier precipitation."
In Delhi and Beijing, air pollution frequently reaches a level deemed by the World Health Organization to be too hazardous. Citizens of these cities must stay inside as much as possible and sometimes wear facemasks when going outdoors. The new research has shown that the pollution is affecting other parts of the world as well.
"Since the Pacific storm track is an important component in the global general circulation, the impacts of Asian pollution on the storm track tend to affect the weather patterns of other parts of the world during the wintertime, especially a downstream region [of the track] like North America," said Wang.
Assisted by a team in China, the U.S. study researchers analyzed computer models depicting the Asian air pollution affecting storm patterns over the Pacific. They found tiny pollutant particles being blown into the northern Pacific and mixing with rain droplets.
"Aerosols provide seeds for cloud formation," study co-author Renyi Zhang, an atmospheric sciences professor at Texas A&M University, told CNN. "If you provide too many seeds, then you fundamentally change cloud patterns and storm patterns."
The researchers said it causes storm clouds to grow denser, therefore inducing more intense storms.
"We are becoming increasingly aware that pollution in the atmosphere can have an impact both locally - wherever it is sitting over regions - and it can a remote impact in other parts of the world," Ellie Highwood, a climate physicist at the University of Reading who was not involved in the study, told BBC News. "This is a good example of that.
"There have also been suggestions that aerosols over the North Atlantic effect storms over the North Atlantic, and that aerosols in the monsoon region over South Asia can affect circulation around the whole of the world."