Nature-Based Solutions for Urban Resilience

Cities worldwide are facing resilience challenges as climate risks interact with urbanization, loss of biodiversity and ecosystem services, poverty, and rising socioeconomic inequality. Extreme precipitation events, flooding, heatwaves, and droughts are causing economic losses, social insecurity, and affecting wellbeing. Over time, urban resilience challenges are expected to grow, driven by processes such as urbanization, land use, and climate change. Whereas climate change is expected to increase the frequency and intensity of some natural hazards, urbanization can also lead to higher exposure of people and assets in cities. More than half of the global population lives in cities, and more than 70 percent are expected to do so by 2050 (Wijesiri et al. 2020; Nerini et al. 2018). In rapidly urbanizing areas, a significant proportion of urban growth risks to materialize in dense, lower-quality unplanned settlements. In these vulnerable areas, climate impacts are exacerbated—now and into the future—as these settlements are often located in high-risk areas, such as on floodplains or steep slopes (Hallegatte et al. 2017). In addition, poorly maintained infrastructure, such as drainage systems, and impervious surfaces can increase the magnitude of natural hazards, such as flooding and urban heat island effects. The World Bank has a growing portfolio of investments and analytical engagements in urban resilience. In the past, structural interventions to reduce disaster risk and build climate resilience have largely focused on gray infrastructure. However, gray infrastructure will not always be suitable in cost-effectiveness, resiliency, or sustainability. More than ever, nature-based solutions (NBS) are recognized to have a critical role in addressing resilience challenges urban areas (box 1-1). The need to advance nature-based approaches is endorsed by many international agreements and initiatives such as the Sendai Framework for Disaster Risk Reduction, the Sustainable Development Goals (SDGs), and the Paris Climate Agreement. These agreements support an alignment of environmental and risk management goals to address the burgeoning needs of managing climate risk, to confront environmental degradation, to improve the adaptive capacities of vulnerable communities, and to advance public and private investment in disaster risk prevention and reduction (Reguero et al. 2020).

source :

https://openknowledge.worldbank.org/entities/publication/c33e226c-2fbb-5e11-8c21-7b711ecbc725