Progress toward managing rising seas

On Nov. 10, NASA will launch a Falcon 9 rocket from Vandenberg Air force Base in California. Its payload: a Sentinel-6 Michael Freilich satellite, equipped with instruments that will dramatically improve measurement of changes in sea level around the world. 

On the other side of the country, in Washington, D.C., lawmakers recently introduced legislation to constructively manage the challenges that rising sea level will pose for American coastlines. 

Taken together, these two events are evidence of important progress toward understanding and managing the risks of sea level rise. The Sentinel-6 satellite is a remarkable technological achievement while the proposed new legislation breaks new ground in defining needed policies, programs and resources. 

Because of climate change, global sea levels are likely to rise by three to four feet by 2100, and by as much as six to eight feet if efforts to control emissions of greenhouse gases falter. Parts of the American coast may experience sea levels as much as 30 percent higher than the global average due to factors such as ocean currents and sinking land. Unfortunately, the sea level rise occurring by 2100 is simply the first increment of a larger rise that will occur in the decades and centuries ahead. 

The warming climate that is raising sea levels also brings more-severe coastal storms, including storms that threaten the South Atlantic and Gulf Coasts. In the coming decades, these storms will ride on top of higher sea levels and storm surges will reach further inland than before. Coastal communities need to prepare for both more extensive storm flooding and the permanent inundation that will follow as seas rise. 

Millions of Americans and hundreds of coastal communities face extensive storm flooding and permanent inundation with potential losses of coastal property running into trillions of dollars. These cost estimates, however, are based on the existing population along the coasts — and that population is expected to double by 2060. Critical infrastructure — transportation, water utilities and military bases — will be flooded, along with beaches and coastal wetlands. 

Sentinel-6 will provide much-needed data to manage these threats. It will capture more accurate, higher resolution pictures of changes in sea level, measuring sea surface height down to the centimeter for 90 percent of the world’s oceans. This data will help address the critical question of the rate at which the rise in sea level is accelerating. Better understanding will help improve forecasts of future sea level rise and inform work to develop effective response strategies. 

The work of developing those strategies took a big step forward with the Ocean-Based Climate Solutions Act, introduced by Chairman Raúl Grijalva (D-Ariz.) of the House Natural Resources Committee and Rep. Kathy Castor (D-Fla.), who chairs the House Select Committee on the Climate Crisis. The bill authorizes $100 million in funds for state grants for coastal flood hazard planning. Some $200 million will protect coastal wetlands and $3 billion would go to implement shovel-ready projects that use nature-based infrastructure to protect communities and ecosystems. The bill also calls for a new National Sea Level Rise Risk Analysis to produce new products and services that allow coastal communities to plan for present and future coastal flood risk.

An important but controversial strategy for managing coastal flooding is to buy properties at risk and, in some cases, relocate entire neighborhoods to safer ground. Most people don’t want to leave their home, but more severe storms and permanent inundation by rising seas may make relocation the best of the bad options for some places. Hard questions arise around costs, social equity, timing of relocation and where to relocate. The bill calls on the Council on Environmental Quality to engage the public and federal agencies in a major assessment of these issues and to recommend needed actions. 

This legislation is an important first step, but it is certainly not the last; other committees and agencies need to take action. For example, the National Flood Insurance Program needs to stop issuing insurance for new developments in areas expected to be permanently inundated by rising seas. New efforts are needed to reduce coastal flood risks to critical infrastructure assets, like transportation systems and military bases. And, it is time for a national requirement to disclose flood and sea level rise risk when property is sold. 

Still, the launch of innovative technology and the proposal of creative policies are reason to hope that the country will step up to the challenge of coastal flood management.  

Jeff Peterson is a retired senior policy advisor at the Environmental Protection Agency and the author of “A New Coast: Strategies for Responding to Devastating Storms and Rising Seas.”