Researchers at the University of Surrey have produced tailored practical guides for city planners in Nepal, Ethiopia and Malawi, showing how strategic use of plants and trees can reduce dangerous air pollution, bring down street temperatures and manage flood risk.
The guides have developed with local scientists, government officials and universities in each country in reponse to an urgent public health challenge. Air pollution claims tens of thousands of lives annually across the three nations, with average PM₂.₅ levels in Addis Ababa running at more than six times the World Health Organisation’s recommended limit.
In Malawi, the problem is compounded by widespread reliance on wood and charcoal for cooking, which nearly all households depend on. Nepal faces its own acute crisis, with fine particle pollution linked to nearly 49,000 adult deaths per year in recent estimates.
The toolkits were produced through the UKRI-funded RECLAIM Network Plus, led by Surrey’s Global Centre for Clean Air Research, and build on an original UK-focused guide published late last year. But rather than simply transplanting that guidance overseas, the research team worked with local partners to adapt the advice to the specific pressures, climates and vegetation of each country.
The focus areas differ accordingly. Nepal’s guide addresses air pollution, urban heat and biodiversity loss. Ethiopia’s covers air pollution, heat and public health. Malawi’s version tackles air pollution, heat and the growing threat of urban flooding.
The underlying evidence shows that the right greening can make a significant difference. Dense hedgerows around two metres tall, with appropriately leafy and textured foliage, can cut roadside pollution levels by up to 63%. Combining hedges with tree planting can reduce pollution by more than half in open road settings. Green spaces and tree cover have also been found to lower surface temperatures by several degrees during peak heat periods, with measurable cooling already documented in parks in Kathmandu and Addis Ababa.
Critically, the guides also warn against common errors. Planting trees in narrow urban streets, for instance, can make air quality worse by trapping pollutants at ground level rather than dispersing them.
Professor Prashant Kumar, who led the project, emphasised that the guides were designed to be genuinely usable by the people who need them: ‘Urban greening works best when it is designed for the place it serves. These toolkits put evidence in the hands of the planners, councils and ministries who can act on it.’
Ganesh Paudel, Joint Secretary, Ministry of Forests and Environment, Nepal, said: ‘As Nepal is rapidly urbanising, this toolkit is published in such a time that it will serve as a guideline to ensure resilient urbanisation. The practical examples from Nepal makes the toolkit more contextual and adaptable by local governments and urban planners. This toolkit will be used to build local capacity and support evidence-based planning and implementation regarding urban greening. We expect it to contribute to more resilient ecosystems, more liveable cities and stronger community engagement for sustainable development in Nepal.’
The toolkits can be found here: https://reclaim-network.org/urban-greening-how-to-toolkits-international-adaptations
Photo: Avel Chuklanov / Unsplash
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