In 2015, California declared a state of emergency and ordered the evacuation of 11,000 residents living in the vicinity of the Aliso Canyon oil field, where, over a period of nearly four months, 100,000 tons of methane escaped from an underground natural gas storage facility. Emissions from this leak alone were the climate equivalent of the annual emissions of half a million cars -- nearly $20 million worth of natural gas.
While incidents like Aliso Canyon may be the exception from a single source volume standpoint, they are indicative of the nature of methane emissions – they are unpredictable, even from major, permitted operational facilities that have vested economic and safety reasons to prevent them.
public health and safety
Consider what may be occurring today across the sizable natural gas production, transportation, and storage infrastructure in Pennsylvania, where self-reported emissions from certain sectors of the natural gas industry statewide eclipse Aliso Canyon.
Methane emissions are not just an economic and climate issue, they are a public health concern. Releases of methane from oil and gas production are comingled with Volatile Organic Compounds (VOCs), which contribute to increases in ground-level Ozone levels, and other Hazardous Air Pollutants (HAPs) like benzene. Both VOCs and HAPs are deemed adverse to human health.