Planting trees in cities is a cheap way to tackle their air pollution problems, according to a study.
Research by The Nature Conservancy (TNC) suggests the average reduction of particulate matter close to a tree is between seven per cent and 24 per cent, the BBC reported.
Particulate matter is what gets trapped in people’s lungs when they breathe in polluted air. The TNC thinks pollution by particulate matter could be responsible for more than six million deaths a year by 2050.
Indeed, air pollution is a big problem in many cities around the world. According to the World Health Organization, more than 80 per cent of people who live in urban areas where air pollution is monitored are exposed to air that exceeds recommended quality limits, with people in low-income cities the worst affected.
Dr Rob McDonald, the study’s lead author, said city trees offered lots of benefits to people in urban areas.
"The average reduction of particulate matter near a tree is between seven and 24 per cent while the cooling effect is up to 2C (3.6F). There are already tens of millions of people getting those kinds of benefits," he told BBC News.
Dr McDonald said the research, which looked at the use of trees in 245 cities, found them to be a cost-effective way of cooling and cleaning air.
"On that front, trees are cost competitive with other options," he told BBC News.
"When you change a bus from diesel to gasoline, for example, you reduce particulate matter pollution, and trees are certainly in the same ballpark."
Ensuring too that the embedded carbon contained in trees is only released as a last resort is also an important aspect of ensuring a healthy environment. The UWW campaign believes that wood should be subject to a ‘cascade of use’ to ensure that it could only be burnt for the production of energy when no other viable options were available. This would ensure that the carbon had the potential to remained locked for decades.