With its Global Emissions Offset futures contract—ticker GEO—CME aims to illuminate a fast-growing market that has thus far operated in a black box via privately negotiated transactions, said Peter Keavey, CME’s global head of energy. “A lot of emissions trading and carbon-reduction projects are unique and regional in nature,” Mr. Keavey said. “Ultimately you need to develop a more global benchmark and viewpoint to harmonize the valuation and trading of offsets.”

Prices will be derived from transactions on a voluntary-offset exchange operated by Xpansiv, a firm that makes markets in data-based assets linked to energy, agriculture and ESG investing. The credits sold must have been verified by one of three carbon registries, organizations that uphold project standards and certify offsets.

Offset buyers on Xpansiv’s platform currently browse credits by price and project, said Andy Bose, the firm’s head of ecosystems and partnerships. Xpansiv, which won’t disclose prices until the monthly futures contracts begin trading on March 1, created a spot contract in conjunction with them. Both are intended to satisfy bulk buyers who care more about price per ton than provenance, Mr. Bose said.