Natural gas is the cleanest burning fossil fuel available.

Greenhouse gas emissions from natural gas are approximately 30 per cent lower than oil and 45 per cent lower than coal.

Compared to coal, natural gas produces less than half as much carbon dioxide; less than one tenth as much nitrogen oxides (causes smog); less than one percent as much sulfur oxides (causes acid rain) and less than one percent as much PM2.5 micro-particulates (causes respiratory complications).

Air pollution contributes to the death of more than 400,000 people in Europe, 1.2 million people in China and 2 million people in the rest of the developing world.[2] Air pollution from Asia even travels across the Pacific Ocean and affects our air quality in North America. By using cleaner burning natural gas from BC, countries in Asia and the developing world can significantly reduce the use of coal and oil in their homes, vehicles and factories. (World Health Organization, Burden of disease from Ambient Air Pollution for 2012)

Using natural gas instead of coal for a 500 megawatt power plant for one year is the equivalent of taking 557,000 cars off the road. [1]

For more information:
BC Air Quality
BC LNG Alliance
Center for Liquefied Natural Gas (CLNG)
LNG 101 (Government of BC)

References:
[1]Center for Liquefied Natural gas
[2]Western Economic Development