Does Natural Gas pollute the earth? If so, how?

Natural gas does pollute the earth as it still emits a large amount of carbon into the atmosphere in the form of both CO2 and methane.

Air pollution
Cleaner burning than other fossil fuels, the combustion of natural gas produces negligible amounts of sulfur, mercury, and particulates. Burning natural gas does produce nitrogen oxides (NOx), which are precursors to smog, but at lower levels than gasoline and diesel used for motor vehicles. Or Natural gas is most commonly extracted by drilling vertically from the Earth's surface. ... Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access, and thus increase its productivity.

The answer is ozone layer.