Just as
oil and natural gas
fields have been found to be emitting more
methane than official government estimates suggest, a new study shows that more
methane than previously thought may be leaking
from the other end of that system — cities, where people actually use natural gas for heating and cooking.
For instance, Nixon states that «it was argued by some that [
methane and carbon dioxide emissions
from flaring in Nigerian
oil fields during the 1990s] was the single greatest contributor worldwide to climate change».