World View: Advance the ecosystem approach in cities

To make cities better for people and the planet, the approach must become more systemic and pragmatic, and include the global south, according to Xuemei Bai, professor of Urban Environment and Human Ecology at Australian National University.

Bai shares her thoughts in Nature’s World View on how to “Advance the ecosystem approach in cities.” She is an inaugural Science Committee member of Future Earth, and has been leading the development of its Urban Knowledge Action Network, which brings practitioners and decision makers together with the researchers to co-produce actionable knowledge.

Read the full World View piece here.

In the piece, Bai advocates for an ecosystem approach: incorporating nature into urban settings to make them more sustainable. She cites the Vertical Forest (Bosco Verticale) in Milan, Italy and the sponge city approach in China. Especially in developing countries, she says, the ecosystem approach “can have significant benefit and co-benefit,” such as flood reduction at lower cost than conventional engineering provides.

The ecosystem approach, however, is not only about bringing more green into cities. It includes “utilizing and maximizing the ecosystem services from nature in and surrounding cities,” Bai says. “A more fundamental element would be seeing cities as a unique ecosystem: a human dominant complex, dynamic and evolving system that are linked to its local and global hinterlands, and apply systems principles in managing them.”

Yet a major obstacle to the ecosystem approach can be how much or how little a population values the integration of green into its urban spaces, as Bai learned during her experience implementing this practice in a community in Ma'anshan, China.

“They simply didn’t see the point, as traditionally vegetation in cities tend to be ornamental, with beautiful flowers or trees that require a lot of management. Regenerating ‘native’ forest doesn’t resonate with the traditional view of how urban green should look like. This comes down to how we recognize the ecosystem service and enhance awareness of it to the urban residents.”

Another obstacle, as mentioned in recent Nature editorial, “Science must help to make city living sustainable,” is how to reconcile urban solutions when sustainability and resilience come into conflict. Science can help calculate and define the risks and benefits, but it will be up to policymakers and governments to take action.

The ecosystem approach is still at an early stage of application in practice, with many opportunities and challenges ahead. Bai argues that it needs more in-depth critique and analysis, as “there are a lot of potentials, [such as] water purification using wetlands and reduced runoff and flood through more vegetation… [but] there is little critique on the effectiveness, efficiency, constraints and scalability.”

This World View piece builds on Bai’s recent comment in Nature, “Six research priorities for cities and climate change,” and a publication from 2016 in Current Opinion in Environment and Sustainability with fellow Urban Knowledge Action Network members, “Defining and advancing systems approach for sustainable cities.”

Bai will speak on 11 July 2018 at the Springer Nature event on Science and the Sustainable City in the World Cities Summit in Singapore. The panel, “Putting urban science to work,” will showcase some of the latest thinking in science-policy linkages in urban spaces for a global audience of decision makers and practitioners.