Recent extreme weather events and the acceleration of climate change, paired with decarbonization efforts that are not on track, make climate-related disruption unavoidable for urban environments, raising the issue of climate-risk adaptation. Moving past what can be done to prevent climate change, there is a strong imperative to develop strategies to prepare urban environments to cope with inevitable challenges such as sea-level rise, floods, water scarcity or extreme heat. The following discusses how cities can build resilience and adapt to undergoing and expected future climate threats.
Climate Action as a Priority
Lately, it appears that climate change has taken centre stage in both urban planning and politics, accompanied by a newfound acknowledgement of the issue’s severity. According to a Eurobarometer survey, 9 out of 10 Europeans consider climate change the single most serious problem facing the world. World leaders also recognize the threat, as the G7 2021 summit has established an emergency fund for climate-linked disasters. Ever since the 2015 Paris agreement, mitigating climate change has been, at least declaratively, a common goal worldwide. Various initiatives like the newly adopted EU climate law imposing the reduction of climate emissions, Norway’s plan to bury CO2 in depleted oil and gas fields under the North Sea, or New York’s recent investment in carbon-capturing technologies, all focus on slowing down climate change and capping global warming at 1.5 degrees Celsius above pre-industrial levels.
However, climate change is already unfolding, and it has accelerated. According to a World Meteorological Organization report, by 2025, there is a 40% chance that the 1.5 degrees threshold is exceeded for at least one year. Only last week, Greenland experienced the third most significant ice melting event in the past decade. As the ice surface continues to shrink, coastal cities become more vulnerable to storm-surge flooding. At the same time, Europe, North America and the Middle East are already experiencing frequent heat waves. In 2020, Siberia recorded a 38 degrees Celsius summer temperature for the first time on record.
The important takeaway from these events is that cities can already experience the effects of climate change, and they need to increase their preparedness. McKinsey’s latest report, developed in partnership with the C40 Cities Climate Leadership network, underlines a series of hazard-specific actions and also explores how cities can identify the most suitable response for their particular risk. This kind of research highlights the importance of climate action at the city level, using either nature-based or systemic and infrastructural measures.
Adapting to Rising Sea Levels and Floods
Oceanographer John Englander, author of Moving to Higher Ground: Rising Sea Level and the Path Forward, says that even if slowing down global warming succeeds, sea levels are still going to rise, meaning coastal cities need to adapt. There are various ways to incorporate adaptive features in the design of buildings located in areas at risk of flooding, from elevating the structure above flood level, building with water-resistant materials or constructing barriers. At the urban planning level, various cities are implementing large-scale infrastructure works such as sea walls and surge barriers. Other strategies are more environmentally focused, involving the restoration of existing protective ecology such as mangroves and wetlands, which would mitigate the impact of floodwater on cities.
As Florida is already experiencing climate disruption, Miami has recently revealed its plan to alleviate the risk of flooding and fortify the coastline against increasingly frequent and stronger storm surges. Among the measures detailed in the 40-year plan are new seawalls and breakwaters, creating wetland ecosystems, as well as elevated construction. The Netherlands, with more than 25% of land below sea level, has amassed extensive experience in creating defences, having developed a 3.700km network of dams and seawalls. Moreover, the city of Rotterdam has adopted a Climate Change Adaptation Strategy, which integrates flood control into the urban design with the help of squares that retain water during peak rainfall, among other measures. In China, where most large cities are affected by flooding, authorities are implementing a sponge city strategy, which requires 80% of urban land to absorb or reuse 70% of stormwater.
Fighting Heat Waves and Drought
Prolonged heatwaves have been setting records in recent years, and cities have been devising various ways of combating the urban heat island effect. In 2017, New York launched the Cool Neighbourhoods plan that proposed street tree plantings, green roofs to replace impervious surfaces and light-coloured pavements with a high albedo that would reflect more of the sun’s radiation. Similarly, Abu Dhabi launched a design competition to develop localized solutions to urban heat island effects through a network of hubs that act as a refuge. In 2016, the Colombian city of Medellin launched the Green Corridors initiative that created a network of greenery, which helped reduce the average city temperature by 2 degrees Celsius.
The vulnerability of cities to droughts is increasing worldwide, and actions vary from short term ones like water restrictions to more structural nones like desalinization and water reuse. After the 2018 severe drought, Cape Town has reduced its water usage by 38% by implementing behavioural -change programs. Other measures for fighting droughts and water scarcity are monitoring technologies that regulate water consumption and the shift of agriculture towards more drought-resistant crops. Cities can also implement more comprehensive water management strategies that take into consideration drinking water, as well as stormwater and wastewater.
The architecture practice should be at the forefront of these efforts; however, the profession is not fully committed to either fighting climate change or designing for resiliency. Perhaps the greatest challenge in human history, climate action needs a concentrated effort in which architects and urban planners must get involved.