Preparing for a future marked by sea level rise

Cover Photo: Seawall in Ventura County, California. Credit: Al Seib/Los Angeles Times

By Emily Vidovich. Emily has a background in environmental journalism and sustainability and is a member of the George Washington University Class of 2019.

The new Sixth Assessment Report of the Intergovernmental Panel of Climate Change (IPCC) states that human-driven climate change is “very likely” the primary driver of increased rates of sea level rise over the last fifty years. Even if humans reduce greenhouse gas emissions in alignment with scientific recommendations, our emissions to date will still warm the oceans and melt ice sheets—making it likely that the global sea level will rise 12 inches above its year 2000 level by 2100. 

The National Oceanic and Atmospheric Administration (NOAA) calculates that in a worst-case scenario where humans do not address climate change, there could be over eight feet of sea level rise during this century. In any likely future scenario, sea level rise will have repercussions on landscapes and livelihoods, including the loss of coastlines as well multi-billion dollars worth of damage to property and infrastructure. In 2019, the Los Angeles Times described how sea level rise is already affecting the state of California:

“The coastline is eroding with every tide and storm, but everything built before we knew better—Pacific Coast Highway, multimillion-dollar homes in Malibu, the rail line to San Diego—is fixed in place with nowhere to go…Seaside cliffs are crumbling in Pacifica, bringing down entire buildings. Balboa Island, barely above sea level, is spending $1.8 million to raise the wall that separates it from the ocean…Winter storms pummeled a Capistrano Beach boardwalk, turning the idyllic shoreline into a construction zone as bulldozers rushed to stack boulders into a barricade. From San Diego to Humboldt counties, homeowners scramble to fend off increasing erosion and storm surges, pleading with officials for bigger seawalls that can hold back the even bigger ocean…For every new seawall protecting a home or a road, a beach for the people is sacrificed.”

Seawall in Ventura County, California. Credit: Al Seib/Los Angeles Times

Low-income communities, people of color, and indigenous populations often are exposed to climate change’s worst impacts, with sea level rise exemplifying this in various ways—low-income coastal communities have less resources to fund solutions such as seawalls, and a recent study predicts that sea level rise will force 500,000 people to relocate from New Orleans, a city where nearly 60 percent of the residents are African American. In the Pacific Islands, indigenous communities are already facing 0.5 inches of sea level rise annually. Eight islands have already been completely submerged, and experts warn that 48 more could be completely underwater by 2100. 

In the coming decades, people displaced by sea level rise will join the nascent population of climate refugees—people whose places of residence have been made unlivable by climate change due to factors such as sea level rise, drought, famine, and extreme temperatures. The World Bank estimates that just within the regions of Sub-Saharan Africa, South Asia, and Latin America, climate change will force 143 million people to move by 2050. 

Hoping to stop sea level rise is not a realistic approach, since greenhouse gas emissions will not be eliminated overnight and the impacts of climate change play out on a timescale that surpasses the human lifespan. A special report on the oceans and climate change from the IPCC projects that sea level rise will continue for hundreds of years, with next century’s rate of sea level rise likely surpassing that of the 21st century. The certainty of continued sea level rise, along with the fact that its effects are already being experienced, makes adaptation and preparedness of coastal communities the appropriate response. 

Change in sea level since 1993. Credit: NASA

In California, seawalls have been the default tactic for protecting coastal buildings from sea level rise. But these partitions between humans and nature aren’t just unsightly, they result in significant fiscal and environmental costs. The Center for Climate Integrity calculates that California taxpayers could spend $22 billion on seawalls to protect the state by 2040. Since sea walls inhibit the coast’s natural sand replenishment process, beaches adjacent to them will shrink and disappear. 

Despite the risk they pose to coastlines, approximately 30 percent of Southern California’s coast is currently obstructed by seawalls of some sort. The damage to shorelines caused by seawalls has prompted several coastal states—including Oregon, North Carolina, and Maine—to ban new seawalls, while other states have imposed restrictions on their construction. 

Unfortunately for coastal property owners, the alternative to building walls in a failing attempt to hold back the surging tide is acquiescing to the inmutable forces of nature intensified by human activity. The concept of “managed retreat,” accepting that some coastal communities will be made unlivable by sea level rise and encouraging people to move inland, has understandably been unpopular with people whose homes, livelihoods, and senses of identity are intertwined with the coast. Sea level rise will undoubtedly alter coastal living over the next century, and if we do not mitigate climate change, the idyllic coastal way of life will cease to exist as we know it.

Sea level rise cannot be stopped, but it can be limited by effective climate action. A recent study modeling sea level rise scenarios found that if humanity limits global warming to 1.5 degrees Celsius, it could cut the contributions of melting ice to sea level rise in half by 2100 compared to a 3 degrees Celsius warming scenario, which is what we are on track to reach if current global emissions trends and insufficient emission reduction pledges remain unaltered. But seeing as the latest IPCC report projects that the planet will very likely reach 1.5 degrees of warming by 2050, it will take decisive, sweeping global action immediately to maintain the possibility of avoiding worst-case scenarios for both climate change and sea level rise.

Island nations have been leading the charge in advocating for halting fossil fuel use in order to limit climate change to 1.5 degrees Celsius. For example, leaders of Pacific nations have been increasingly critical of the Australian government for its expansion of coal mining. But it is not only the governments of these nations that are taking action—the Pacific Climate Warriors is a coalition of grassroots, frontline, and indigenous people from throughout the Pacific region that educates youth on climate action and spearheads a fossil fuel divestment campaign aimed at limiting global warming. The members of the Warriors, whose ancestors have been stewards of the ocean for millenia, are carrying on this stewardship by fighting climate change and raising awareness about sea level rise while proclaiming, “we are not drowning, we are fighting.”