There are over 2.1 million abandoned oil and gas wells across the United States. These unplugged wells are a danger to wildlife and unsuspecting humans. Open wells also release gases like methane into the atmosphere. The cost to plug an unused well ranges from $3,500 to $80,000.
Only Mother Jones article, and the summary includes no details on emission quantities, or useful facts, other than cost of closing a well. Soooo much journalism here.