In the last five years, the number of organizations supplying carbon credits into the market has doubled. While finding a vendor to offset your emissions may be easy, differentiating the companies can be difficult.

The CarbonTracker Network hopes to change that by partnering four organizations to build a reliable set of options for individuals or businesses hoping to offset the emissions they just can't avoid. CarbonTracker.com, Sustainable Travel International, co2balance and Offsetters Climate Neutral Society are the first vendors to sign up.

Other vendors can join for free, but they must provide third-party certification that their offsets are created in accordance with certain standards, or they must pass a review by CarbonTracker.com staff.

This seems like a smart move for carbon vendors if they wish to garner buyers' trust and money. Plus it couldn't hurt to provide a little certification for carbon offsetting.