During recent market turmoil and a meltdown in commodities, the Global Carbon ETN (GRN) [-10%] has held up much better than oil (USO) [-35%] and natural gas (UNG) [-45%] and about the same as the overall market S&P 500 ETF (SPY), with the approximate three month returns listed after each ticker.

Key factors in the demand for carbon credits include overall power demand and the relationship between natural gas and coal prices since burning gas results in the release of less than half of the greenhouse emissions versus coal. Currently, the simplest way for power utilities to reduce greenhouse emissions is to convert from coal to gas.