Luke Elson defends carbon offsetting on the basis that it is not moral-ly objectionable to shift harms or risks around. As long as emitting and offsetting does not increase the overall harms or risks—and mere-ly shifts them—compared to refraining from emitting, he suggests there is no injustice involved. I respond in several ways, suggesting that the time delay involved in offsetting can increase these risks but, regardless, there is a defensible default which could justify refraining from emitting, even when planning to offset.