Protected areas remain the most commonly used tool for in situ conservation; however growth in the USA's system of public lands has stagnated while private land conservation continues to expand.

Protected area downgrading, downsizing and degazettement (PADDD) is a global phenomenon that has not received formal attention in Reducing Emissions from Deforestation and Forest Degradation (REDD+) policies designed to reduce forest carbon emissions and conserve biodiversity.