Effects of US biofuel policies on US and world petroleum product markets with consequences for greenhouse gas emissions

► Biofuel policy has counter-intuitive greenhouse gas effects under certain conditions. ► US biofuel policies affect global petroleum markets, with implications for GHGs. ► US biofuel use mandate GHG effects depend on whether they are binding and who pays. ► US biofuel GHGs are sensitive to policy, petroleum market responses, and biofuel trade.