1. Near 100 countries agree to collaborate to ensure at least 30% of the planet is protected by 2030 and to establish a future role for the coalition to support implementation. High Ambition Coalition for Nature and People (21 June 2022).
2. Conserving and Restoring America the Beautiful (US Department of the Interior, US Department of Agriculture, US Department of Commerce and Council on Environmental Quality, 2021); https://www.doi.gov/sites/doi.gov/files/report-conserving-and-restoring-america-the-beautiful-2021.pdf
3. Lindholm, J. & Barr, B. Comparison of marine and terrestrial protected areas under federal jurisdiction in the United States. Conserv. Biol. 15, 1441–1444 (2001).
4. Richards, R. Measuring Conservation Progress in North America (Center for American Progress, 2018).
5. The World Database on Protected Areas (WDPA) and World Database on Other Effective Area-based Conservation Measures (WD-OECM) (UNEP-WCMC and IUCN, 2021); https://www.protectedplanet.net/en