This study seeks to evaluate and understand potential environmental consequences of exporting Powder River Basin (PRB) coal compared to global alternative sources of coal. Some of the questions that arise in regards to environmental impacts of PRB exports to Asia include the following. (1) Which stages of the life cycle (e.g., mining, transport, power plant combustion) contribute the most to environmental impacts? (2) How do environmental impacts at each stage differ between the PRB and competing countries? (3) Do environmental impacts differ substantially based on the importing country? (4) Is there a definitive difference between the life cycle greenhouse gas (GHG) profiles between sourcing coal from the U.S. (PRB), Australia, or Indonesia for Japan, South Korea, or Taiwan?