Trees shade city streets and parks raise property values. Trees provide cooling shade and help moderate run-off after storms. They’re good for the mind and body. Urban forests help cleanse the air of pollutants, reducing the incidence of respiratory disease. And their presence makes you feel better: a study in Toronto found that having an additional 10 trees on a city block improved peoples’ perceptions of their health by an amount comparable to a $10,000 increase in income or being seven years younger.
Nearby forests provide urban-dwellers with water, energy, and protection from weather extremes.
Nearby forests provide many of the services that underpin everyday life in the world’s cities. Many of those cities – including Bogota, New York, and Singapore – have invested in protecting forested watersheds to ensure dependable supplies of clean, fresh water for drinking and sanitation. Forested catchment areas also fill the reservoirs behind hydroelectric dams that power city lights.
As climate change increases the frequency and severity of extreme weather events, the role of forests in attenuating the impacts of those events is increasingly apparent. Natural forest vegetation helps mitigate the landslides and flooding that often result from heavy rainfall. Restoring tropical mangrove forests could help buffer coastal cities, such as Mumbai, from storms and sealevel rise. And in alpine areas, trees on steep slopes can help mitigate avalanche risk after heavy snowfalls.
“Trees in urban areas make people healthier and happier.”
Far-away forests supply timber and protect the climate.
Cities do not depend just on trees in their immediate vicinity. Timber sourced from far-away forests has long been used for urban construction needs with rot-resistant tropical species favoured for outdoor uses such as pavements and park benches. A renaissance in the use of wood in urban architecture is underway, combining its inherent aesthetic and structural properties with new technologies to erect efficient, lowcarbon “mass timber” buildings more than 10 stories tall.
“Forests constitute up to 1/3 of the cost-effective actions to prevent catastrophic climate change.”
In addition, new science is revealing the role of forests in ensuring global well-being, including the sustainability of cities, through their roles in moderating the climate both locally and globally. Forests are now estimated to constitute up to 1/3 of the cost-effective actions to prevent catastrophic climate change, including reducing emissions from deforestation and enhancing carbon storage through reforestation and restoration. Moreover, the role of forests in regulating hydrological cycles is now understood to operate at the local watershed level and to play a role in generating rainfall across continents, thus ensuring the continued productivity of the world’s agricultural systems. Yet consumer choices still contribute to forest loss: the leading cause of tropical deforestation is conversion of forests to commercial agriculture to serve global commodity markets: forests yield to pasture for beef, cropland for soy, and plantations for palm oil and fastgrowing timber.
What can cities do to protect faraway forests?
Many cities already recognize the value of urban and nearby forests, and are actively working to protect and enhance tree density to reap their many benefits. In 2017, 17 Asian countries participated in a conference in Korea organized by the United Nations Food and Agriculture Organization (FAO), which produced an Action Plan for the development of urban and peri-urban forests in the region. Awareness of what cities can do to protect faraway forests, however, is still embryonic, but urban leaders can do at least 3 things that would make a difference:
1. Enact forest-friendly procurement policies. These would include avoiding the sourcing of products associated with deforestation, unless those products are independently certified as legally and sustainably produced. Providing markets for legal and sustainable timber can provide incentives for keeping forests as forests rather than converting them to other uses.
2. Provide a market for forest ecosystem services, especially carbon. Many of the world’s leading cities have made commitments to achieve carbon neutrality by mid-century or before. Most emission reductions can and should be achieved by reducing fossil fuel use in the energy and transport sectors, but the purchase of forest carbon offsets from tropical jurisdictions could be the icing on the cake.
3. Raise awareness. Most urban-dwellers are unaware how much their well-being depends on goods and services generated by faraway forests, and what they can do to promote forest conservation. Urban environmental education can help citizens make more forestfriendly choices with their spending and voting power.
Why Forests? Why Now? The Science, Economics and Politics of Tropical Forests and Climate Change
Frances Seymour and Jonah BuschSee the publication