Los Angeles epitomizes the many climate-driven hazards that confront cities today — wildfires, air pollution, heat waves, coastal erosion, flooding, and drought. As the effects of climate change intensify, cities worldwide are increasingly investing in infrastructure projects to safeguard their communities from escalating risks.
Urban infrastructure projects often rely on engineered designs and components, such as the cement walls lining the L.A. River, to reduce flooding risks. However, a new focus on integrating built and natural infrastructure promises better environmental, social and economic outcomes. In Los Angeles, one example is the USC Public Exchange Urban Trees Initiative, which aims to enhance resilience to rising temperatures by expanding tree coverage, particularly in vulnerable communities.
While nature-based solutions can be cost effective in reducing hazards such as coastal flooding or urban heat islands, they face challenges. For example, while studies show that living shorelines can be as effective at reducing coastal erosion as conventional gray infrastructure methods like seawalls, and can provide additional benefits (such as habitat and recreational opportunities), there is no standard manual for constructing living shorelines. The approach might depend on factors such as local ecology, wave energy and erosion rates. They can also be harder to fund and permit relative to traditional engineered structures made of concrete and steel.
To realize the potential of nature-based solutions across the United States, in 2022 the White House launched a roadmap to unlock the potential of these solutions, including by prioritizing additional research. “Collaboration between government institutions, civil society, academia and the private sector is key to harnessing the power of our built and natural environment to reduce hazards,” said Doug Mason, assistant director for nature-based solutions in the White House Office of Science and Technology Policy (OSTP).