Doubling the number of trees in major cities would reduce air pollution and energy use, study finds
By michellesimmons // 2018-01-24
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Megacities have a population of at least 10 million people, and they largely rely on the ecosystem services provided by remote natural area. A study found that planting 20 percent more trees in major cities would reduce air pollution and energy use by two times. The study was conducted by a team of researchers from Parthenope University of Naples in Italy. In the study, the research team utilized the i-Tree Canopy tool to measure the current tree coverage in cities as well as the potential for more urban forest cover and worked out the benefits that would bring. They assessed the current tree cover in ten major cities on five continents and looked at the benefits of urban forests, such as eliminating air pollution, saving energy, and providing food. In addition, they estimated the current value of those benefits at over $500 million each year. The researchers also created a model for each major city that considered the local megacity tree cover, human population, air population, air pollution, climate, energy use, and purchasing power. With these, they discovered that every city could possibly host 20 percent more coverage of forest canopy. Even so, city planners and authorities have to change their view of the natural resources available to cities before residents can benefit from the effects of more trees. Metropolitan areas will be healthier and more sustainable if fewer cities depend on nature outside urban areas and focus more on conserving nature within the cities. "By cultivating the trees within the city, residents and visitors get direct benefits," explained Theodore Endreny, lead author of the study. "They're getting an immediate cleansing of the air that's around them. They're getting that direct cooling from the tree, and even food and other products. There's potential to increase the coverage of urban forests in our megacities, and that would make them more sustainable, better places to live."

The researchers suggest that city planners, residents, and other stakeholders should begin looking at cities for natural resources and plant more trees in urban areas to conserve nature.

The benefits of planting more trees in cities

Urban trees are so much more than being decorations along the sidewalks. In fact, a lot of studies suggest that planting more urban trees could save thousands of lives across the globe by reducing pollution in the air and cooling down heat waves.

A report by researchers from the Nature Conservancy found that urban trees benefit the health of the public in at least two ways – by soaking up fine particle pollution and cooling down neighborhoods. Urban trees improve air quality as they can soak up fine particles emitted by cars, power plants, and factories that harms the lungs of people. Moreover, urban trees cooling down the temperature is essential, especially during deadly heat waves. Since temperature would be cooled down, many households could reduce their use of air-conditioning units. This, in turn, would result in lesser energy consumption and slow down the pace of global warming. Furthermore, trees can retain stormwater, enhance real estate values, and may even provide mental health benefits. (Related: Our relationship with nature is vital to mental well-being: Scientists have tracked how we are affected by exposure to trees, the sky, birdsong in real-time).

However, tree planting campaign in urban areas must be well planned. Cities need to consider several factors such as which neighborhoods benefit most from new trees, what plant species are most effective at trapping pollution, wind patterns, tree spacing, and how to maintain the trees.

Read more stories on environment, climate change, global warming, and such at Enviro.news.   Sources include:

ScienceDaily.com

Vox.com

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