The Michigan Court of Appeals has held that the Michigan Department of Environmental Quality is not required under the state's Natural Resources and Environmental Protection Act ("MEPA") to promulgate rules regulating carbon dioxide emissions. In Citizens for Environmental Inquiry v. Department of Environmental Quality, No. 286773 (Mich. Ct. App. February 9, 2010), the appellate court affirmed the Ingham County Circuit Court, which had granted MDEQ's motion for summary judgment in connection with its denial of a citizen group's request that the agency promulgate such rules.

The plaintiffs were a group of residents trying to prevent issuance of a state air permit to build a coal-fired power plant in northern Michigan. The Court of Appeals found that the only alleged injury was a generalized claim of "global warming and/or climate change" and that the plaintiffs had failed to show that they had a "clear legal right to the promulgation of specific rules regarding CO2 emissions." The court distinguished between the type of special distinct injury necessary to obtain mandamus relief and an allegation of injury suffered by the general public.

The court also rejected the plaintiffs' claim that MDEQ's issuance of air permits without imposing standards for carbon dioxide emissions violated MEPA, holding that to bring a claim under that statute, a plaintiff must be able to show that the defendant either polluted, impaired, or destroyed, or is likely to impair or destroy, air, water, or natural resources—something the plaintiffs' complaint did not allege.