The University of Maine System announced Thursday that it reduced climate-warming carbon dioxide emissions by 26 percent statewide over the last eight years. It also said dependence on heating oil at its campuses is expected to drop by 49 percent over the next year through the use of efficient, alternative-fuel heating systems. The university’s campuses used about 1.1 million gallons of heating oil in fiscal year 2015 and expects to cut the system’s dependence on the fuel by 536,000 gallons in time for the 2016 heating season, according to Thursday’s announcement. In 2006, the public university system released about 97,500 metric tons of carbon dioxide and gases with equivalent climate impact.