The Global Change Assessment Model Version 3.0 defines three different levels of “Protected Lands” within the agricultural and landuse component. These three different scenarios effectively cordon off 3.5% (5.0 million km2) of the Earth’s terrestrial lands in the de minimus Protected Land Scenario, 5.0% (7.20 million km2) in the Core Protected Land Scenario, and 8.2% (11.8 million km2) in the Expanded Protected Land Scenario. None of these scenarios represents the “right” level of Protected Lands for the planet today or tomorrow. Rather, the goal is to create a range of scenarios that can be used in modeling human responses to climate change and the impact those would have on managed and unmanaged terrestrial lands. These scenarios harness the wealth of information in the United Nations Environment Programme World Conservation Monitoring Centre’s World Database on Protected Areas and its categories of explicit degrees of protection.