Urban planning in the age of climate crisis

Extreme weather events are escalating worldwide, primarily attributed to climate change driven by human activities. Recent studies have shown that 71% of the analysed 504 extreme weather events were either made more likely or more severe due to anthropogenic climate change. These events include heatwaves, heavy rainfall, and severe storms, all intensifying in frequency and magnitude.

Moreover, climate-proofing is a matter of safeguarding physical infrastructure and involves significant economic implications. Cities are economic powerhouses, generating a significant portion of global GDP. When extreme weather strikes, the economic disruption can be immense. According to a study published in Nature, annual global costs attributed to such extreme weather have reached approximately US $143 billion, with a significant portion of these costs linked directly to climatic changes.

Adaptation to climate change is increasingly recognised as a crucial component in managing the economic impact of extreme weather events. Such events’ rising frequency and intensity necessitate robust adaptation strategies to mitigate the associated risks and costs.

For instance, improving infrastructure resilience, such as enhancing flood defences and updating building codes, and implementing early warning systems are essential steps. These adaptations reduce the vulnerability of communities and curb the economic losses that often follow extreme weather events, which have been shown to be significant. For example, between 1970 and 2019, weather and climate-related disasters resulted in over $3.64 trillion in losses globally.

Specific measures, like the development of heatwave adaptation strategies following the deadly 2003 heatwave in Europe, illustrate the effectiveness of such policies.

France’s introduction of a heat warning system significantly reduced fatalities during subsequent heatwaves, demonstrating that well-implemented adaptation policies can dramatically lessen the impacts of extreme weather.

Furthermore, the economic rationale for investing in adaptation is compelling, with studies suggesting that every dollar spent on making infrastructure more resilient may save six dollars in future losses.

Addressing environmental challenges

The paper “Climate Proofing Cities by Navigating Nature-Based Solutions in a Multi-Scale, Social-Ecological Urban Planning Context” highlights the importance of integrating nature-based solutions (NBSs) into urban planning as a strategic approach to climate-proof cities.

By conserving urban green spaces and utilising ecosystem services, such as water regulation and flood control, cities can enhance their resilience against the adverse effects of climate change. The paper advocates for simplified, cost-effective modelling techniques to estimate ecosystem services related to water run-off mitigation. This approach enables urban planners to assess the impacts of green spaces on different scales under various climate scenarios using user-friendly, open-source tools like the InVEST model.

Furthermore, the paper emphasises a multi-scale, social-ecological approach to urban planning, which includes local, sub-drainage basin, and regional considerations to manage ecosystem services effectively. This includes implementing nature-based solutions like green roofs, urban parks, riparian buffer zones, and constructed wetlands that harness natural processes to address environmental challenges.

By incorporating these strategies into urban development, cities cannot only mitigate the impact of climate change, such as flooding and heatwaves but also promote urban sustainability and improve the quality of life for their residents.

Adverse weather events

Apart from this, the floods in cities due to climate change warrant cities to be ready to deal with incessant rainfalls (like recently in Dubai). Cities can integrate advanced hydrological models and urban infrastructure planning, focusing on mitigation and adaptation strategies.

Applying low-impact development (LID) techniques such as permeable pavements, green roofs, and bioretention facilities is crucial. These systems mimic natural hydrological regimes by promoting infiltration, evapotranspiration, and rainwater reuse. Permeable pavements, for example, allow stormwater infiltration through porous materials, thereby reducing surface runoff and enhancing groundwater recharge.

In addition to green infrastructure, technological advancements in flood prediction and risk assessment play a pivotal role. Urban areas benefit from employing hydrodynamic models that simulate water flow and volume across various storm scenarios.

These models aid in identifying critical flood-prone areas and assess the effectiveness of existing and proposed flood mitigation infrastructures. For instance, integrating Geographic Information Systems (GIS) with urban hydrological models allows for spatially explicit simulations of flood events, facilitating targeted interventions in urban planning and development.

Studies, such as those by G. Zhou et al. (2015) demonstrate how urbanisation influences flood frequency and severity and the utility of GIS in creating detailed flood risk maps that help in planning appropriate flood defence mechanisms. Additionally, applications like those highlighted by R. Thompson et al. show that integrating GIS with hydrological models can optimise disaster response efforts by directing resources and assistance efficiently during flood events.

Thus, advanced spatial and simulation technologies will not only help manage the increasing flood risks associated with climate change but will also help our cities be better prepared against adverse weather events.

Aditya Sinha (X:@adityasinha004) is Officer on Special Duty, Research, Economic Advisory Council to the Prime Minister of India. Views Personal.