Bridging air and water resilience: How systems thinking can create innovative urban solutions

With nearly 70% of the world’s population expected to live in cities by 2050, the pressure to make urban environments healthier, more liveable and more sustainable has never been greater.

As we close London Climate Action Week 2025, a global platform showcasing leadership in urban climate solutions, it is important to reflect on cities as dynamic ecosystems where climate, infrastructure, environment, governance and social equity are deeply intertwined.

Cities are particularly susceptible to what are known as “wicked problems” – complex, interdependent and often politically charged challenges that lack a single, clear solution.

These problems are difficult to define, span across sectors and disciplines and often have no clear end-point, no best and no true solution – only options that are better or worse depending on your perspective.

Some of the global risks identified by world leaders in the recent World Economic Forum’s Global Risk Report 2025 identified several wicked problems – pollution (including water and air) being among the top 10 global risks in both the short and long term.

The evidence for pollution is particularly stark: currently, 99% of the world’s population live in areas with air pollution above recommended guidelines from the World Health Organization and one in three people globally lack access to safely managed drinking water.

You can’t always see pollution in the air, but around 7 million premature deaths are attributed to its effects annually.

Exposure to poor air quality is associated with several health challenges, including respiratory disease, stroke and heart disease. It’s also associated with inequity.

Eighty percent of those exposed to unsafe air pollution are living in low and middle-income countries and studies show inequities in air pollution exposure relating to race and gender.

Due to the heterogeneous nature of pollutants, their sources and solutions, air pollution poses complexity and uncertainty to decision-makers.

If air pollution is the invisible killer, water challenges are often the visible but overlooked assailant. Whether they are too much, too little or too polluted, cities everywhere are struggling to manage their water systems under increasing pressure.

Urbanization, climate change and outdated infrastructure combine to create cascading risks, from flash floods and sewage overflows to unsafe drinking water and ecosystem degradation.

In the face of such intertwined challenges, systems thinking provides a powerful lens for understanding and addressing urban complexity.

Rather than treating issues in isolation, systems thinking promotes a holistic understanding of the relationships between them – encouraging cross-sector collaboration and the pursuit of co-benefits while minimizing unintended consequences.

In recent years, experts have begun applying systems thinking to address the dual challenge of pollution in the air and water, recognizing that solutions are more effective when designed with the whole system in mind.

To support systems-thinking approaches for cleaner air, researchers have identified opportunities to rethink science-policy efforts.

Recently, a systems-thinking decision-making tool was tested in a pilot study for air pollution, bringing together diverse stakeholders from across the air pollution system to co-create objectives and evaluate actions towards achieving clean air.

By engaging across the system, it identified the ripple effects and trade-offs of actions, such as the negative impact of electric vehicle demand in high-income nations on the health and environment of communities involved in rare metal mining in Africa.

In the United Kingdom, participatory systems mapping has been used to create causal maps of the air quality and transport nexus, illustrating the unintended consequences of electric vehicle policy on health and social wellbeing.

It has been shown how transforming urban mobility through systems thinking can revolutionize urban design, improve physical activity and associated health benefits, and reduce the impact of stress, noise and traffic-related deaths, all while improving air quality.

Imagine the benefits if we took systems thinking to address all pollution sources in cities; the benefits reaped could be astounding.

Despite their severity, water issues are often still treated in silos — dividing drinking water, wastewater, and stormwater management — when, in fact, they are deeply interconnected.

Similarly to air pollution, there is an opportunity for governance to overcome this through systems thinking.

Approaches such as integrated water management and emerging concepts, including water neutrality and water neutral governance, offer ways to reduce water stress while promoting co-benefits for climate, health and equity.

This is where systems thinking also becomes crucial to advancing water innovation. New tools, data platforms and governance models are helping cities better understand and respond to water risks.

The Water-BOOST systems toolkit, developed as part of the Hoffmann Fellowship in Water Innovation, supports urban leaders and practitioners in assessing systemic water challenges and identifying scalable, cross-sector solutions that align infrastructure, policy and innovation efforts.

Whilst there is growing evidence of systems thinking being applied to tackle the challenges in both air pollution and water systems, the real opportunity lies in bridging these two domains and embedding systems thinking across the wider urban environment.

Doing so can unlock powerful co-benefits that extend beyond pollution control – improving climate resilience, public health, social equity and overall well-being.

A recent review of nature-based solutions illustrates this potential. For example, green roofs can help manage stormwater, easing pressure on urban drainage systems, while simultaneously improving air quality through the use of plant leaves.

These solutions also contribute to carbon capture, create urban habitats for biodiversity, and provide cooling and aesthetically pleasing public places.

This demonstrates how a single, carefully designed intervention can serve multiple objectives.

By identifying and investing in these co-benefits, cities can tackle wicked problems simultaneously, aligning policies and innovation efforts to deliver more efficient, inclusive and resilient urban environments.

A cross-sectoral response is essential; cities can no longer afford to treat air, water, climate and health in isolation.

To move from theory to impact, systems thinking must be embedded in practice. There are synergies in the actions that can be taken to encourage systems thinking for cleaner air and urban water practices. Cities can start by:

The sooner cities adopt these practices, the sooner they can move beyond crisis management toward building long-term resilience, well-being and sustainability in the face of complex, wicked problems.