Seven forecast scenarios.

The U.S. military is a significant contributor to the climate crisis and other sustainability concerns. However, there is very limited research on how changes in U.S. military spending directly impact Department of Defense energy consumption and thereby greenhouse gas emissions. Here, we conduct a time series analysis of the relationship between U.S. Department of Defense (DOD) direct energy consumption and U.S. military expenditures from 1975 to 2022, and we test for directional asymmetry in the effect of expenditures on energy consumption. We estimate error correction models, which we ensure are free from residual autocorrelation and structural breaks. We find that a decrease in expenditures has a larger effect on decreasing energy consumption than an increase in expenditures does on increasing consumption. Further analyses reveal that this is due to cuts in DOD energy consumption from facilities and vehicles and equipment, and jet fuel in particular. We also illustrate the potential impacts of different spending decisions on DOD energy consumption and present a forecast from 2023 to 2032 for seven different scenarios. We show that sustained cuts to U.S. military expenditures could result in annual energy savings on par with what the nation of Slovenia or the U.S. state of Delaware consumes annually by 2032.