Urban trees can tackle pollution, heat waves
A report points out trees and other types of vegetation, when planted along a city street or grown in a park or residential yard, provide multiple benefits to people
Planting trees is beneficial as tree leaves filter out particulate matter from the atmosphere, along with other pollutants Credit: Suelen Miranda/Flickr
The 21st century is the "urban century", as more than 2 billion additional people arrive in cities all over the world. A report terms this rapid urbanisation unprecedented in human history and points out that by 2050, more and more people will live in urban areas.
This poses a huge challenge as cities across the world are facing several problems at present from providing jobs to a burgeoning population to safeguarding urban environmental assets and striving for sustainability so that posterity does not suffer.
Health burden
Today, our cities are facing monumental problems. They have to protect their drinking water supply, manage waste, build parks and plant street trees for their residents. However, the biggest challenge that cities face is ensuring healthy air.
The report focuses on two crucial issues: air pollution and high temperatures. Globally, particulate matter is the ambient air pollutant with the largest health burden. It is responsible for an estimated 3.2 million premature deaths annually in both rural and urban areas, the report says. Pollution also causes other problems such as coughs, asthma, bronchitis, irregular heartbeat and non-fatal heart attacks.
Besides air pollution, exposure to high temperatures leads to a number of negative health effects. Acute exposure to heat, combined with dehydration, can lead to heat cramps and fainting. Continued exposure can lead to heat exhaustion. In even more serious cases, acute exposure to extremely high temperatures can cause heat strokes.
The report adds that urban heat waves will pose a greater challenge for cities in the coming years. As cities add on more people, housing all urban dwellers requires developing land. If in this process, forests are destroyed, it would only increase the urban heat island effect. According to experts, climate change will make heat waves more frequent and intense.
Green saviours
The report points out trees and other types of vegetation, when planted along a city street or grown in a park or residential yard, provide multiple benefits to people.
These include aesthetic beauty, erosion prevention, storm water management and noise reduction. Trees also sequester carbon and help mitigate climate change. Planting trees is beneficial as tree leaves filter out particulate matter from the atmosphere, along with other pollutants. Trees can help make air healthier and cities more verdant and livable.