our website<\/a>.<\/p>\npoor air quality has led to an explosion of asthma cases and other health problems among vulnerable populations including children, the elderly, and low-income residents. each year bad air causes two million deaths worldwide. also, in the u.s., there have been 8,000 premature deaths from excessive heat over the past 25 years. urban heat islands, which are caused, in part, by sunlight being absorbed by paved surfaces and roofs, lead to higher surface temperatures, up to 90 degrees. atmospheric air temperatures are also higher: in the day by up to 6 degrees, and at night, by up to 22 degrees. vulnerable populations also face greater risks of heat exhaustion. (source: world health organization (who) and heat island impacts, u.s. environmental protection agency (e.p.a.) )<\/p>\n
increasing the tree canopy in cities is one way to fight both poor air quality and urban heat islands. research shows significant short-term improvements in air quality in urban areas with 100 percent tree cover. there, trees can reduce hourly ozone by up to 15 percent, sulfur dioxide by 14 percent, and particulate matter by 13 percent. u.s. trees remove some 784,000 tons of pollution annually, providing $3.8 billion in value. furthermore, a single large healthy tree can remove greater than 300 pounds of carbon dioxide from the atmosphere every year. in fact, new york city\u2019s urban forest alone removes 154,000 tons of co2 annually. through their leaves, trees also provide evaporative cooling, which increases air humidity. shaded surfaces may be 20-45 degrees cooler, and evapotranspiration can reduce peak summer temperatures by 2-9 degrees. (source:\u201cheat island mitigation: trees and vegetation, u.s. environmental protection agency (e.p.a.) and \u201csustaining america\u2019s trees and forests,\u201d david j. nowak, susan m. stein, paula b. randler, eric j. greenfield, sara j. comas, mary a. carr, and ralph j. alig, u.s. forest service. )<\/p>\n
some other benefits: urban forests reduce energy use by providing shade in the summer and wind breaks in the winter, reduce stormwater runoff, remediate soils, and provide animal and plant habitat. trees have economic benefits: they increase property value. lastly, trees have positive cognitive effects and may even help improve moods. (source: \u201csustaining america\u2019s trees and forests,\u201d david j. nowak, susan m. stein, paula b. randler, eric j. greenfield, sara j. comas, mary a. carr, and ralph j. alig, u.s. forest service; \u201cdoes looking at nature make people nicer?\u201d the dirt blog and \u201cthe restorative effects of nature in cities,\u201d the dirt blog)<\/p>\n","protected":false},"excerpt":{"rendered":"
inhale, exhale! unless the air is dirty, that is. cleaning up the air is a problem that many cities face. the american society of landscape architects says that by planting more trees and creating urban forests, cities can be a cleaner and healthier place to live!<\/p>\n","protected":false},"author":8831,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[4905,4893,4907,4916,4894,4900,4895,4904],"tags":[2050,858,2051,859,178,237,496,2395,736],"storyfest_categories":[],"class_list":["post-13699","post","type-post","status-publish","format-standard","hentry","category-adaptation","category-architecture","category-business-economics","category-climate","category-efficiency","category-green-living","category-transportation","category-water","tag-american-society-of-landscape-architects","tag-architecture","tag-asla","tag-construction","tag-design","tag-green","tag-sustainable","tag-t","tag-trees"],"acf":[],"yoast_head":"\n
growing urban forests: the secret to cleaner, cooler, city air - planet forward<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n