This study uses established procedures to estimate the effects of changes in mortality and growth implant protocols on feedlot net returns (NRs). We then propose new methods for estimating concurrent impacts to feedlot greenhouse gas emissions intensity. Reducing mortality consistently increases NRs and reduces greenhouse gas emissions intensity in the feedlot regardless of sex or placement weight. Results indicate that use of two implants in the feedlot may increase NRs and reduce greenhouse gas emissions per pound of dressed beef produced, compared to just one growth implant.