Adapting Cities in the Climate Change Era
With their endless amenities, opportunities, and services, it’s no wonder that so much of the world’s population is attracted to cities. While there are many advantages of urban life, large concentrations of people spur great challenges as well, many of which are enhanced by climate change and erratic weather.
Over the last few years, climate change has brought scorching heat waves, severe flooding, and other natural disasters to the heels of cities. Cities now must rethink disaster mitigation to protect not only their residents and infrastructure, but decade’s worth of progress.
Approaches to Creating Resilient Cities
How can we create resilient cities that are sustainable and adaptable? It starts with cross-disciplinary collaboration. Landscape architects, urban planners, and architects must work together to create a city that can support the surprises and changes of Mother Nature. Here are a few approaches that cities have turned to so far:
Weather Phenomenon: Floods
Heavy precipitation and increased hurricanes are a frightening reality for a number of cities across the globe. Temperature increases allow the atmosphere to hold greater amounts of water, which in turn, leads to more intense rainfalls. As cities are largely surfaced by impermeable materials like asphalt, this makes them highly susceptible to flooding. This is why the idea of a “sponge city” is so enticing. Sponge cities use an ecological approach to hold, clean, and drain water naturally. Rather than funneling it away, the water can be retained for future use through the integration of permeable pavements, raised walkways, and natural floodplains like wetlands. By retaining and absorbing the incoming water, cities can shield infrastructure from the effects of heavy rainfall.
Another interesting concept is the idea of planting “forest walls” that act as buffers between communities and threatening waves. Trees planted along the coastline can lessen the force of incoming tidal waves when they are fully grown. This approach protects both communities and environments from dramatic effects.
Weather Phenomenon: Heat waves
Heat waves are a huge problem for cities. While rural areas are faster to cool, cities tend to retain heat. In areas with over one million residents, temperatures can be 1.8-5.4 degrees warmer than surrounding areas, which can lead to temperature differences as much as 22 degrees Fahrenheit after sunset. Urban planners can leverage wind paths to create ventilation corridors by orienting new buildings to enhance air flow and naturally cool urban streets to combat this effect.
Building material choices also make a difference. Cities are often covered by dark roofs and pavement that absorb heat. By painting roofs white or replacing them with more reflective materials, this can transfer up to 35% of their energy to buildings below them.
As the effects of climate change worsen, resiliency must become a priority for our cities. To adapt to changing weather patterns, groups and stakeholders from different disciplines must work together to design and implement protective measures. By making sustainable changes now, we can safeguard the urban environments that we have created over many generations, and continue to provide new opportunities for many generations to come.
Image from Wikimedia Commons