Tropical forests help people live safer, healthier, and more productive lives in many ways, not least by reducing climate change. In fact, tropical forests contribute to achieving more than half of the 17 sustainable development goals agreed by world leaders in 2015.
Goal 1: No poverty
Communities living in or near tropical forests get an average of 21% of their income from forest products other than timber, according to a survey of 24 countries. However, there is often more money to be made by clearing forests for beef pastures, soy fields, or oil palm plantations – though often by different people than those who benefit from rainforests. So the challenge for forest conservation is to find ways to make them worth more alive than dead. Eco-tourism and international carbon payments are just two of the ways this can be done.
Goal 2: Zero hunger
Tropical forests’ contributions to food security go far beyond the fruits, nuts, vegetables, mushrooms, and meats that account for 7% of the income of households living in and around them. The birds, bees, and bats that live in forests improve the productivity of nearby fields by providing free pollination and pest control. Forests also recycle moisture as cool, wet air that is better for downwind farming, while their cover contributes to the health of inland fisheries. They even support breadbaskets at continental scales by creating vapour clouds or “flying rivers” that carry atmospheric moisture from the Amazon to the fertile growing regions of southern Brazil.
Goal 3: Good health and wellbeing
Tropical forests are a source of both traditional and modern medicines. People living in and around Makira National Park in Madagascar use 241 local plants as medicines to treat 82 types of illness. Modern medicines derived from rainforest plants include vinblastine (an anti-cancer drug), progesterone (an ingredient used in contraceptives), quinine (an anti-malarial), and tubocurarine (a muscle relaxant). Mature tropical forests also suppress malaria due to cooler temperatures, less standing water, and more species that eat or compete against mosquitoes.
Goal 6: Clean water and sanitation
Forests keep water clean by preventing erosion and filtering out pollutants. Converting Indonesian forests to oil palm plantations was found to cause a 500-fold increase in sediment in streams. To preserve water quality, cities as diverse as Bogota, Harare, and Singapore have set aside protected areas in upland watersheds.
Goal 7: Affordable and clean energy
Hydroelectric dams supply two-thirds of Latin America’s electricity, and the productivity of these dams depends on having an abundant, reliable, and clean supply of water. Forests limit the amount of sediment that flows into reservoirs, maintaining generation capacity and avoiding costly repairs and dredging. Where deforestation has been rampant, as in the watershed above Haiti’s Péligre Dam, electricity production has plummeted (pdf).
Goal 8: Decent work and economic growth
Forests make many economic contributions to developing economies, but you wouldn’t know it by looking at gross domestic product (GDP), which doesn’t count goods and services that don’t enter formal markets. However, economic estimates of the value of forests, and the costs when they are destroyed, are becoming more common. The World Bank calculated that Indonesia’s catastrophic 2015 forest fires caused $16bn (£13bn) in damages to health, infrastructure, and agricultural output – more than double the potential revenue from growing palm oil in cleared areas.
Goal 9: Industry, innovation and infrastructure
Forests form a natural “green infrastructure” that protects towns from floods, fires, droughts, and other natural disasters. Hillsides with less deforestation had fewer landslides after a deadly 1999 tropical storm in eastern Mexico; and coastal mangrove forests protected villages from deadly waves following the super cyclone in Odisha in 1999 and tsunamis in the Indian Ocean in 2004 and Japan in 2011.
Goal 13: Climate action
Deforestation is the second-leading cause of climate change after burning fossil fuels. On many days in 2015, forest fires in Indonesia produced more greenhouse gas emissions than the entire US economy. Net deforestation is responsible for about 10% of climate emissions. When you consider that forests can remove carbon from the atmosphere too, protecting tropical forests while restoring damaged forests could contribute up to 24-30% of the potential climate solution.
Goal 14: Life below water
Forests don’t just keep carbon dioxide out of the atmosphere, they also keep it out of the ocean, where it forms carbonic acid and breaks down the calcium carbonate that marine animals need to form hard shells. Meanwhile, coastal mangrove forests serve as breeding grounds and nurseries for a wide variety of fish, crustaceans, and other sea life. 30% of the fish catch in southeast Asia and 60% of commercial fish species in India rely on mangroves at some stage of their life cycle.
Goal 15: Life on land
Tropical forests are extraordinarily diverse, ranging from high montane cloud forests to lowland seasonally flooded forests to dry deciduous forests, each with its own distinct array of plant and animal life. One square kilometre of tropical rainforest in Malaysia can contain more tree species than all of the US and Canada; a single tree in the Peruvian Amazon may be home to more ant species than the entire British Isles. Conserving tropical forests protects the habitat of two-thirds of all species, including some of the most charismatic: jaguars, gorillas, orangutans, and birds of paradise.
Forest conservation, long at the centre of efforts to protect earth’s biodiversity, is increasingly understood to make important contributions to the other SDGs as well.
To learn more about how tropical forests contribute to a stable climate and sustainable development, read Why Forests? Why Now? The Science, Economics, and Politics of Tropical Forests and Climate Change by Frances Seymour and Jonah Busch.