Environmental Conservation, Protected Areas, and SDGs

Environmental conservation is the protection and sustainable use of nature and natural resources, protected areas are geographically defined places managed to achieve long-term conservation, and the Sustainable Development Goals (SDGs) are 17 global goals adopted by the United Nations in 2015, several of which concern the environment. In brief: about 17% of the world’s land and 8% of the ocean were protected in the early 2020s, and in 2022 governments agreed to protect 30% of land and sea by 2030 (the “30 by 30” target). Conservation works in places (in situ, such as national parks) and outside them (ex situ, such as seed banks and zoos), and it is most effective when local communities share in the decisions and benefits.

Biodiversity is declining faster than at any time in human history, and protecting nature is essential for climate, water, food and well-being. This guide explains the types of protected area and the IUCN categories, other conservation approaches, how conservation is linked to the SDGs, compares the categories in a table, works through calculations, outlines the history and corrects common mistakes.

What are protected areas?

The International Union for Conservation of Nature (IUCN) defines a protected area as “a clearly defined geographical space, recognized, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values.” The IUCN classifies them in six categories according to the level of protection and use (see the table). Examples include strict nature reserves and wilderness areas, national parks such as Yellowstone (established in 1872, often called the first national park), Serengeti and Kruger, natural monuments, wildlife sanctuaries, protected landscapes where people and nature have shaped each other for centuries, and areas for sustainable use of natural resources. Marine protected areas, such as the Great Barrier Reef Marine Park and the Papahānaumokuākea Marine National Monument in Hawaii, protect ocean ecosystems. International designations include World Heritage Sites, Biosphere Reserves (UNESCO) and Ramsar sites for wetlands (the Ramsar Convention, 1971).

Protected areas help to conserve species and habitats, regulate water and climate, support tourism and livelihoods, and preserve cultural values. Their effectiveness depends on size, connections between them (wildlife corridors), funding, enforcement and the support of local people. Many are “paper parks” with weak protection. Early parks sometimes removed Indigenous peoples from their lands, and this “fortress conservation” is now widely criticized. Today, there is greater recognition of the role of Indigenous peoples and local communities, who hold or manage around a quarter of the world’s land, including many areas of high biodiversity.

What other conservation approaches are there?

• In situ conservation: protecting species in their natural habitats, through reserves and habitat management.
• Ex situ conservation: protecting biodiversity outside natural habitats, in zoos, botanic gardens, gene banks and seed banks such as the Svalbard Global Seed Vault in Norway, which opened in 2008. Captive breeding has helped species such as the California condor.
• Species protection and law: endangered species lists (the IUCN Red List), national laws, and the Convention on International Trade in Endangered Species (CITES, 1973), which regulates the wildlife trade.
• Biodiversity hotspots: regions with a high number of endemic species that are under threat, 36 of which have been identified, such as Madagascar and the Atlantic Forest of Brazil, used to focus investment.
• Sustainable use and community-based conservation: allowing regulated harvesting and sharing the benefits, as in the community conservancies of Namibia, where local people manage wildlife and receive income from tourism and hunting concessions.
• Restoration and rewilding: repairing damaged ecosystems and reintroducing species, such as wolves in Yellowstone.
• Economic tools: payments for ecosystem services, ecotourism, certification (for fisheries and forests) and the reform of harmful subsidies.

How is conservation linked to the SDGs?

The 17 SDGs, with 169 targets, were adopted in 2015 for 2030. The most directly relevant are SDG 14 (Life below water), which includes conserving at least 10% of coastal and marine areas, SDG 15 (Life on land), which covers forests, drylands, mountains, biodiversity and land degradation neutrality, SDG 13 (Climate action), SDG 6 (Clean water and sanitation) and SDG 12 (Responsible consumption and production). Nature also underpins food security (SDG 2), health (SDG 3) and poverty reduction (SDG 1), because people depend on ecosystems for food, water, medicines and income. The Convention on Biological Diversity (1992) is the main treaty on biodiversity, and in December 2022 the Kunming-Montreal Global Biodiversity Framework set 23 targets for 2030, including protecting 30% of land and sea, restoring 30% of degraded ecosystems and reducing harmful subsidies. Conservation can conflict with development goals, such as when land is needed for farming or energy, so trade-offs and local participation are central.

IUCN protected area categories

Worked example: coverage, targets and species loss

The values are approximate or hypothetical and illustrate typical calculations.

1. Protected share: the world’s land area is about 149 million km². If 17% is protected, 0.17 × 149 = 25.3 million km² are protected.
2. The 30% target: to protect 30% of the land, 0.30 × 149 = 44.7 million km² are needed. The gap is 44.7 − 25.3 = 19.4 million km². Since Russia covers about 17.1 million km², the gap is about 19.4 ÷ 17.1 = 1.1 times the area of Russia.
3. Ocean: the ocean covers about 361 million km². With 8% protected, 28.9 million km² are covered. A target of 30% means 108.3 million km², so 79.4 million km² more are needed.
4. Species-area relationship: the number of species S in an area A is about S = cA^z, where z is about 0.25. If 90% of a habitat is lost, 10% (0.1 of the area) remains. The remaining share of species is 0.1^0.25 = 0.562, so the habitat would eventually lose about 1 − 0.562 = 43.8% of its species.
5. Reserve size: halving an area (A × 0.5) keeps 0.5^0.25 = 0.841 of the species, a loss of 15.9%.
6. Funding: a park of 2,000 km² costs 2,000 × 800 = 1,600,000 a year to manage, at 800 per km². If tourism brings in 2,400,000, the park has a surplus of 800,000 that can support local communities.

How did conservation develop?

Early protection existed in royal hunting reserves and sacred groves. The modern conservation movement grew in the 19th century, with figures such as John Muir and Theodore Roosevelt in the United States, and Yellowstone became the first national park in 1872. The IUCN was founded in 1948, and the World Wildlife Fund in 1961. The 1970s saw major treaties: the Ramsar Convention (1971), the World Heritage Convention (1972) and CITES (1973). The Rio Earth Summit of 1992 produced the Convention on Biological Diversity, and in 2015, the SDGs were adopted. The 2022 Kunming-Montreal framework replaced the earlier Aichi targets, most of which had not been met. Conservation thinking has moved from excluding people toward partnerships with local and Indigenous communities and from protecting single species toward restoring whole ecosystems.

Which mistakes are common?

Mistake 1: Assuming that a protected area is automatically well protected

Many protected areas lack funding, staff or enforcement, so the quality of management matters as much as the area covered.

Mistake 2: Thinking that protected areas must exclude people

Several categories allow sustainable use, and conservation is often more effective when local communities are partners with secure rights.

Mistake 3: Judging success only by percentage of area

Location matters: protecting remote, low-value land is easy but may not safeguard threatened species. Places rich in biodiversity and well connected should be a priority.

Mistake 4: Treating conservation and development as opposites

The SDGs link them: healthy ecosystems support food, water, health and livelihoods. Good planning looks for solutions that serve both.