Carbon monoxide is the 5th biggest source of climate change as it contributes a total of 6.7% to climate change. Carbon monoxide is actually a very weak greenhouse gas on its own. However when it is released into the air it destroys hydroxyl (HO), a naturally occurring gas in our atmosphere that shortens the lifespan of other greenhouse gasses.
Without hydroxyl, greenhouse gasses can stay in the air for longer and do more damage to our environment making carbon monoxide, even though it does not directly affect the environment, a significant source of global warming.
The main source of carbon monoxide is from more developed countries where the biggest source of carbon monoxide is the exhaust from cars and trucks. In less developed countries, however carbon monoxide is also produced by the burning of various plant matter.