Worldwide, heat waves account for the deaths of 12,000 people per year while exposure to high levels of air pollution causes up to three million deaths per year. Many of these deaths occur in large urban cities as an increasing number of the earth’s population are choosing to live in urban rather than rural locations.
The World Economic Forum (WEF) claims there is “One beautifully simple action that municipal leaders can take to reduce both extreme heat and air pollution: plant more trees.” It further claims that planting trees “Is a one-two punch of environmental action.” This is due to the fact that trees and other green vegetation are responsible for naturally cooling the air around but also because they act as filters and are capable of reducing particulate matter (PM) levels in the surrounding 30 metres by as much as 25%.
Planting trees, particularly in large urban centres, should be viewed as a low-cost solution that can lead to a reduction in greenhouse gas emissions as well as improved health levels of societies. A global investment of only $100 million could potentially provide as many as 68 million people with significant reductions in PM levels while also contributing to a 1-degree Celsius reduction in air temperature for 77 million people. Additionally, “An investment equivalent of $4 per person could save 11,000-36,000 lives annually and reduce adverse health effects for tens of millions of people.”
Where tree planting as a climate change reduction strategy really stands out is in ability to address both urban heat and air pollution. Other strategies such as industrial scrubbers, limits on car, bike and truck traffic and the use of light-coloured building materials are also good strategies that have an important part to play and can be adopted by municipal leaders but they only address urban heat or air pollution and not both simultaneously.
The economic, environmental and health actions of not acting now against rising temperatures and increased air pollution will continue to escalate the longer no action is taken. In 2016, the Organisation for Economic Cooperation and Development (OECD) estimated that “Outdoor air pollution could cause 6 to 9 million premature deaths a year by 2060 and cost 1% of global GDP – around USD 2.6 trillion annually – as a result of sick days, medical bills and reduced agricultural output, unless action is taken.”
The Nature Conservatory claims that by the middle of the 21st century two out of every three people worldwide will live, work and play in cities. As a result of this, heat and air pollution will increasingly constitute major health concerns which will have to be addressed. Not addressing them would result in other negative economic, environmental and health costs arising in the future. However, addressing urban heat and air pollution are not the only benefits that can arise from planting trees.
The WEF states that “They provide habitat for wildlife, reduce storm-water runoff, and sequester carbon from the atmosphere, which helps to mitigate climate change. There is also a growing body of research showing that exposure to trees and other vegetation has a positive effect on mental health, especially for children. All of these co-benefits speak to the wisdom of greater investment in trees and urban green infrastructure such as parks and rain gardens.”
However, planting trees alone will not solve the problems of rising temperatures, increased air pollution and climate change. Yet, they are certainly a critical piece of the puzzle and should be used as a strategy by all types of leaders, strategists and policy-makers worldwide. Strategies for planting trees can also be highly targeted and localised in order to improve the health and wellbeing of a particular city or town’s citizens.
This article was written by Ken Fullerton.
About the author:
Ken Fullerton is an independent sustainable development consultant. He has worked on development related projects in Germany, Senegal, South Africa, Tanzania and Uganda and is passionate about increasing access to renewable energy across Africa. Between May 2011 and September 2015 Kenneth worked for Positive Planet, a French based international non-profit organisation, whose mission it “is to help men and women across the world create the conditions for a better life for future generations.” He holds a Bachelor of Arts degree in History from the University of Otago, New Zealand, a Master of Arts degree in Development Studies from the University of New South Wales, Australia and a Master of Public Management (MPM) degree from the University of Potsdam, Germany. He is a dual Australian and South African citizen.