Urban infrastructure in a changing climate: adapting to the challenges of the 21st Century

Climate change is a global challenge rapidly becoming a defining issue of our time. While taking immediate steps to reduce emissions can help limit global warming to 1.5°C, the consequences of this warming are still unavoidable, and will include increased frequency and intensity of extreme events, significantly impacting physical, social, and economic systems (IPCC, SR1.5, 2018).

The impacts of climate change, particularly in South Asia, are examined in several IPCC reports, including the sixth Assessment Report (IPCC, AR6, 2022) and the Special Report on Global Warming of 1.5°C (IPCC, SR1.5, 2018). Extreme weather events like floods, cyclones, and droughts are increasing in South Asia, causing damage to infrastructure and property leading to economic losses. In urban areas, the impacts of floods can be particularly severe due to the concentration of infrastructure and population. Urban floods are a growing concern in South Asia, with increasing urbanization and climate change making cities more vulnerable to flooding. According to a report by the World Bank, the economic cost of floods in South Asia is estimated to be $7.2 billion annually, with urban floods accounting for a significant portion of this cost.  While cities are centers of innovation and economic activity, they also face significant social, economic, and environmental challenges that necessitate efficient infrastructure development and urban planning. The effects of climate change on urban infrastructure further complicates the Sustainable Development Goals of reducing poverty and achieving other interconnected goals.

To address this issue, it is important to invest in resilient infrastructure that can withstand and adapt to flood events. Climate-resilient infrastructure refers to physical infrastructure that is designed, constructed, and maintained to withstand the impacts of climate change while either remaining in operation or quickly returning to operation after an event. Investing in resilient infrastructure can help to reduce the economic losses caused by urban floods and ensure that communities are better prepared to withstand future flood events. It can also help to promote sustainable development by reducing the long-term costs of repairing and rebuilding infrastructure damaged by floods.

There are three aspects to climate-resilient infrastructure. First, the infrastructure itself is resilient – ensuring that it can endure extreme climatic or climate-induced events. Secondly, the infrastructure ensures climate justice – to ensure that steps taken to build resilience do not lead to shifting the risk onto vulnerable populations. At the urban catchment scale, the drainage system may be designed to be resilient. However, it may happen that flood water diverted towards a waterbody can significantly affect its water quality and hydrology, jeopardizing the livelihood of those who depend on the waterbody’s ecosystem services. Finally, the infrastructure incorporates a sustainable development lens – to ensure risk is not shifted to future generations. In the urban water management system, one may go for building massive structures like, for example, the Tokyo underground reservoir for rainwater storage. But since it is built out of concrete, huge quantities of greenhouse gases were emitted to build it, to some extent defeating the main objective of mitigating climate change. As an alternative, Blue-Green infrastructure and urban landscape design that keeps in mind the hydrology of the catchment can go a long way not just in minimizing the runoff but also in acting as a sink for greenhouse gases, improving the urban climate and the quality of life of the urban population.

There are several challenges to developing climate-resilient infrastructure in South Asia, including limited resources and capacity, lack of coordination among stakeholders, and limited access to climate data and information. To address these challenges, it is important to generate knowledge and build capacity among stakeholders, including policymakers, engineers, and communities, to design and implement climate-resilient infrastructure projects. Investing in research and development in climate-resilient infrastructure can also help to identify best practices and innovative solutions that can be scaled up and replicated in other contexts. This can involve collaborations between researchers, policymakers, and practitioners to identify key challenges and develop practical solutions that can be implemented on the ground. In addition to generating knowledge on climate-resilient infrastructure, it is also important to promote public awareness and engagement to build support for these initiatives. This can involve working with local communities to understand their needs and priorities and incorporating their perspectives into the design and implementation of infrastructure projects.

In conclusion, building climate-resilient infrastructure is critical to sustainable development in the 21st century. We can protect people and property, reduce greenhouse gas emissions, and promote sustainable development by designing, constructing, and maintaining infrastructure systems that can withstand the impacts of a changing climate. As the effects of climate change continue to become more severe, we must give high priority to this work.