Coastal and marine ecosystems store large amounts of carbon in soil sediments and vegetation. When these systems are disturbed through conversion or degradation, this emits carbon dioxide, a greenhouse gas whose growing atmospheric concentration is altering the climate system. Attention to this source of “blue carbon” emissions has only, fairly recently, been motivated by new scientific studies quantifying its magnitude. The United Nations Framework Convention on Climate Change (UNFCCC), as part of its mission to reduce threats to our global climate system, promotes the sustainable management, conservation, and enhancement of sinks and reservoirs of all greenhouse gases, including those in coastal marine ecosystems. Yet there are no specific mechanisms within the UNFCCC that focus on blue carbon. This paper reviews where coastal marine ecosystems and blue carbon may be addressed within existing UNFCCC mechanisms, such as those dealing with land use and reduced emissions from deforestation and degradation (REDD+), at the project and national levels.