More than 80% of people on Earth now live in cities and towns, which means that urban areas have a huge role to play in solving the planet’s climate and biodiversity crisis. 

A new report from the global NATURA network lays out a vision for how cities can harness nature to address climate shocks, biodiversity loss and public health risks while advancing equity and inclusion. 

Nancy Grimm, Regents Professor and Virginia M. Ullman Professor of Ecology at Arizona State University, co-directs the NATURA network. 

Here, she shares some insights from the report, titled Global Roadmap for Urban Nature-Based Solutions.

Question: The roadmap lays out an inspiring vision for greener, fairer cities. What gives you confidence that this change is possible now?

Answer: There is great interest among city planners and managers in using natural features — so-called nature-based solutions — in lieu of expensive alternatives like massive “gray” infrastructure, such as levees, sea walls, huge underground pipes and so on. Nature-based solutions are attractive because they can sometimes be less costly for a city, but also because they simultaneously provide additional benefits and multiple functions. 

For example, a restored streamside forest or wetland can feature nature walks, shading and habitat for birds, while also reducing the height of stormwater flows by absorbing much of it into the ground. So the change is possible because it just makes sense, and is affordable in a wide range of situations.

Q: The roadmap draws from global research but emphasizes local action. How can cities adapt these ideas to their own unique challenges?

A: The roadmap includes a large number of case study examples from around the world, which we hope will provide inspiration. We envision city planners and others using this database to compare their own context with the examples presented. 

The case studies cross a wide range of climate and ecological contexts, socioeconomic capacities, degree of top-down vs. bottom-up planning and governance, and scales of implementation, among other characteristics. 

Each regional report in the road map describes trends and challenges in nature-based solutions implementation, and makes a series of recommendations appropriate for the region.

Q: Nature-based solutions often take time to show results. How can cities balance the need for quick climate responses with long-term investments in nature?

A: This is a great point. And another is that they often require lots of land, which can have high dollar value in a city. But remember that “quick climate responses” to cope with changing conditions and extreme events are often just Band-Aid-type fixes. They don’t get at the basic issues. 

Much of our infrastructure is either not up to the task, having been designed for past conditions, as in much of the Global North, or it is not keeping up with the rate of urban expansion, as in much of the Global South. 

Nature-based solutions work with self-regenerating ecological systems that can obviate the need for extensive repair and also provide the co-benefits for recreation, habitat and other climate adaptations I mentioned earlier.

Q: The report highlights equity and inclusion as essential. What does that look like on the ground?

A: Several things. First, recognizing that poor and otherwise disadvantaged people often have no choice but to live in areas that are the most exposed to climate hazards — places like steep slopes, riverbeds, wetlands and areas with little vegetation to provide shade. We need to prioritize these areas for nature-based solutions. Secondly, all people who are experiencing heightened risk need to be involved in decisions, planning, implementation and management of nature-based solutions in their neighborhoods. And third, we should recognize that there are alternative modes to living sustainably with natural systems that have a long history and deep knowledge from subdominant cultures, especially Indigenous knowledge around the world. 

I’m optimistic that we are beginning to understand the need to work with these alternative ways of knowing and living to move away from the destructive path we’ve been on. A great example of this is cultural burning practiced by Indigenous people in North America.

Q: What impact do you hope this road map will have — both for city planners and for ordinary residents?

A: We can build cities — or change those we already live in — in ways that support people and nature and enhance urban livability. I hope that seeing the great range of examples of mostly successfully implemented nature-based solutions in vastly different contexts will provide inspiration to urban residents.