24 February 2022
To counter environmental perils, cities turn to nature

Cities have long been about carving out a place for humans apart from nature. But that model has begun to change. Urban planners are increasingly realizing that to fend off a growing list of environmental threats, they need to harness what is known as ecosystem-based approaches.

These strategies run the gamut from tree planting to the creation of urban gardens. On 23 February, sub-national leaders will explore ecosystem-based approaches at the United Nations Environment Assembly (UNEA) Cities and Regions Summit.

Hosted by the UN Environment Programme (UNEP), the summit will showcase how nature can help cities reduce greenhouse gas emissions, stave off extreme heat, protect wildlife and filter pollution, all while creating jobs and economic opportunities. For example, UNEP data finds that simply planting trees on city streets would give 77 million people a 1°C reprieve on hot days.

Ahead of the Cities and Regions Summit, here are five municipalities that are embracing ecosystem-based approaches.

“By flipping the script and by connecting our cities and regions with nature, we can address the triple planetary crisis of climate change, nature and biodiversity loss, and pollution and waste,” said Martina Otto, Head of UNEP Cities Unit.

“These inspiring stories of cities and regions that are at the forefront of bringing nature back into cities and reducing pressures on nature are sending a positive message to the discussions that will take place next week at the UN Environment Assembly. We now need these inspiring stories to become the norm.”

1. Surat, India: Greener city, cleaner air

Located on the western coast of India, Surat is aiming to increase green cover to over 25 per cent from 18 per cent. The city is also implementing a public transportation system to reduce congestion and air pollution, in addition to working with the construction sector to follow green building standards.

“When water and trees are adversely affected, so are human beings,” says Shri Banchhanidhi Pani, the Municipal Commissioner of Surat. “That is why sustainability in dense, rapidly developing cities is important. We must consider how best to create that balance between nature and development, and prevent pollution from affecting natural resources and human health.”

Surat is a beneficiary of UrbanShift, a UNEP-led initiative committed to promoting integrated, low-carbon development in more than 23 cities around the world.

2. Rio de Janeiro, Brazil:  Inner-city farming reducing hunger

The Manguinhos Community Garden, the biggest garden of its kind in Latin America, was created as part of an effort to boost economic growth while safeguarding the environment.

To develop the garden, Rio residents removed 700 truckloads of waste, prepared the ground for food crops, and built nurseries, greenhouses and water tanks. Every month, two tons of organic food are distributed to 800 households at no cost. The Rio de Janeiro City Hall is also supporting the Carioca Community Gardens Program. As of 2021, the initiative included 49 community gardens, of which 25 are at schools and 24 are in vulnerable neighbourhoods. The programme supplies around 80 tons of fresh vegetables annually, with half of the produce donated to nearby public shelters, nursing homes and schools.

At the Cities Summit, the International Resource Panel (IRP), together with UNEP will launch Urban Agriculture’s Potential to Advance Multiple Sustainability Goals – An IRP Think Piece that evaluates how urban agriculture can help cities move towards sustainable urban food systems and a circular economy, along with policy guidance including a road map for designing “fit-for-purpose” urban agriculture policies, taking into account the interaction between urban and rural systems.

3. Madrid, Spain: Beating the heat with green corridors

Madrid is looking long-term by building a green wall around the city. The 75-kilometre urban forest, with nearly 500,000 new trees, aims to improve the air quality within the city and lower temperatures. It will absorb 175,000 tons of greenhouse emissions per year and connect to surrounding forests.

4. New York, United States: Turning concrete jungle to urban forest

The New York City Council and the New York Restoration Project have joined forces to plant 1 million trees in five boroughs. Since 2016 there has been an estimated 20 per cent increase in the city’s forest cover, offering New Yorkers an escape from the concrete jungle. The initiative has also been designed to help cool the city. Heat reduction services from urban tree cover in the United States are estimated to save up to $12.1 billion annually.

5. Seoul, South Korea: Uncovering the cooling power of water

In Seoul, an effort to restore the Cheonggyecheon stream replaced 5.8 km of elevated expressway that covered the stream with a mixed-use waterfront corridor. The work decreased local temperatures by 3.3°C to 5.9°C, compared to a parallel road a few blocks away. Seoul has also added nearly 2,000 urban forests and gardens. These projects have increased biodiversity, improved air quality, and reduced ambient temperatures.


UNEP supports countries and cities mainstreaming ecosystem-based approaches by developing knowledge tools and policy guidance such as UNEP’s Integrated Guidelines for Neighbourhood Design.

These tools aim to inspire further action by national governments and city authorities to enhance ecosystem-based approaches in cities to address the planetary crises.

The UNEP-hosted Cool Coalition is supporting actions on the ground, by working with cities worldwide to combat extreme heat by turning to nature, and through the GEF-7 funded impact programme UrbanShift to make use of integrated approaches.

In addition, UNEP engages in key political processes to highlight the importance of ecosystem-based approaches in cities; examples include the G20, the World Urban Forum and UNEA.

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