In the absence of regulatory intervention, voluntary initiatives to measure and verify fugitive and other upstream emissions from natural gas shipments continue to gain ground. Environmental commodity marketplace Xpansiv, for example, issues and provides a platform for trading Methane Performance Certificates (MPCs), which are generated when natural gas is produced with an emissions intensity below a predefined threshold value. MPCs are traded on the spot market with activity tracked by commodity price reporting agencies, allowing producers to sell the certificates independently from the physical natural gas they produce.