The George C. Marshall Institute (GMI) was a nonprofit conservative think tank in the United States. It was established in 1984 with a focus on science and public policy issues and had an initial focus in defense policy. Starting in the late 1980s, the institute advocated for views in line with environmental skepticism, most notably climate change denial. The think tank received extensive financial support from the fossil fuel industry. Though the institute officially closed in 2015, the climate-denialist CO2 Coalition is viewed as its immediate successor.