The author is a member of the PPIC Water Policy Center research network.
October brought a preview of some of the climate risks that coastal regions face. Hurricane Matthew wreaked havoc from Haiti to the eastern seaboard and the West Coast’s first “atmospheric river” storm brought flood warnings in some areas. The risk of coastal flooding is growing as a warming climate causes more intense precipitation and a gradual rise in sea level from Earth’s melting ice sheets. Both worsen the effect of high tides and large storms.
We have a few decades and perhaps up to a century to adjust to sea levels that are at least three feet higher than they are today. Coastal communities can expect a host of costly and dangerous problems from storms, including flooded wastewater treatment plants, shoreline erosion, industrial facilities spilling chemicals into waterways, and water supply systems inundated by seawater. The effects of floods are projected to be the most costly part of climate change. Some estimates put the global losses at $1 trillion a year by 2050, or roughly two percent of global GDP.
Although seas are rising relatively slowly, change will not be gradual at the community level. A series of strong winter storms that combine high tides, large waves, and intense rainfall can radically reshape a community in a matter of days.
For California to adapt, every coastal community will need a plan that envisions a future with higher sea levels and greater risk of coastal erosion and flooding. The plans will need to outline specific projects needed to weather changing conditions over coming decades. Communities will need to figure out how to raise roads, buildings, and critical infrastructure, and ways to enhance natural protective systems, such as beaches. Some combination of building codes and assistance programs is likely to be necessary. So far, most California communities are in the early stages of planning to adapt to rising seas.
Research shows that increasing awareness and knowledge of hazards is not enough to head off losses from disaster. A complicating factor in adaptation planning is how to make the scientific information actionable at the local level.
One new approach shows promise. A UC Irvine program called FloodRISE is bringing together experts in flood disasters, engineering, and the social sciences with local experts and community members in a number of Southern California communities and Tijuana, Mexico. As part of that program, we’re working with decision makers, community groups, NGOs, and personnel from key departments such as public works, city planning, emergency management, and environmental resources. The teams work together to create advanced visualizations of flooding. Using the latest climate science and data, local knowledge and flood modeling technology, they focus on addressing specific issues that communities care about the most.
How well we manage the problem of rising seas will to some degree depend on funding choices we make now. My FloodRISE collaborator Richard Matthew, a political scientist and disaster expert at UCI’s Blum Center for Poverty Alleviation, notes that funding for planning and preventing disaster risks is dwarfed by the resources that pour into communities after disaster strikes. In the chaos of emergency management, decisions must be made quickly and with very limited information, which too often leads to wasteful spending. Allocating more funds to climate-risk planning efforts would not only help local communities prepare for a rising sea and coastal flooding—it could help reduce wasteful spending later.
Read California’s Water: Preparing for Floods (from California’s Water briefing kit, October 2016)
Read “Floods in California” (PPIC Water Policy Center fact sheet, February 2016)
Visit the PPIC Water Policy Center’s floods resource page