Combating climate change requires not only rapid reduction of greenhouse gas emissions, but also removal of significant amounts of carbon dioxide (CO2) from the atmosphere. CO2 removal (CDR) comes in many different forms, but climate scientists and policymakers are focusing on the potentially important role of large-scale use of emerging ocean-based techniques, often referred to as marine CDR (mCDR). In the United States, mCDR in domestic waters is governed by a patchwork of laws and regulations.