Scientific updates added into guidance document and could influence future state legislation.
SAN FRANCISCO — New findings reported by California’s Ocean Protection Council (OPC) gave the California Coastal Commission reason to revisit and update its sea level rise policy guidance document. Commissioners did just that on Nov. 7, unanimously voting to incorporate new science into the policy guidance during their November meetings in San Francisco.
The policy guidance, in general, was crafted to be an evolving document, constantly subject to updated scientific findings.
The current sea level policy guidance update could influence proposed legislation during the next legislative session and gubernatorial administration. Commissioners approved the policy guidance update one day after voters elected a new governor and updated who would represent them in the legislative halls of Sacramento.
California’s Sea level guidance policy, which was guided by NOAA, was adopted by the Coastal Commission in August 2015.
“The guidance is meant to provide information and recommendations for how to address sea level rise in the context of the Coastal Act,” Kelsey Ducklow, a coastal program analyst with the Coastal Commission, said. “Specifically, it includes a set of guiding principles for addressing sea level rise, a summary of sea level rise science, step-by-step processes for addressing sea level rise, and local coastal programs and applications for coastal development permits.”
Coastal Commission staff revisited its sea level rise policy guidance as part of a discussion of how the predicted environmental phenomenon would constrain development. Coastal Commission staff also discussed recent science updates. The current policy guidance update is now based upon a 2018 report created by OPC. The OPC report was adopted in March and, according to Coastal Commission staff, “provides new projections recommended for use in planning, permitting, investment and other decisions.”
“The new findings on sea level rise presented in the [OPC] Rising Seas report, particularly the probabilistic sea level rise projections and increased understanding of ice sheet dynamics, prompted the update to the state’s sea level rise guidance document,” Coastal Commission staff stated in a report to commissioners. “The ‘State Sea-Level Rise Guidance: 2018 Update’ … provides [OPC and the Coastal Commission] and local governments with a science-based methodology to assess sea level rise risks.”
Within the most recent OPC report are new projection tables for the 12 tide gauges located along the California coast. Data collected from the tide gauges help researchers forecast what could happen every 10 years, between 2030 and 2150.
OPC’s report mentioned three sea level rise projection scenarios, which could be used for projects coming in front of the Coastal Commission: low risk aversion (17 percent chance of being exceeded); medium high risk aversion (0.5 percent chance of being exceed); and, extreme risk aversion.
Low risk aversion scenarios would apply to coastal projects with limited consequences or a higher ability to adapt to sea level rise. Medium high-risk aversion, meanwhile, applies to waterfront project proposals with greater potential consequences and/or a lower ability to adapt to sea level rise.
The extreme risk aversion label would apply in an extreme ice loss scenario and used for coastal projects “with little to now adaptive capacity … and/or would have considerable public health, public safety or environmental impacts.”
A comment of “serious concern” was filed by the Port of San Diego in response to the OPC report and Coastal Commission’s proposed guidance policy update.
“The [port] district has serious concern regarding the recommendation application of the probablistic projections for planning and design,” Jason Giffen, the port district’s vice president of planning and green port. “The 2018 Draft Science Update recommends that all communities evaluate the impacts from the ‘medium high-risk aversion’ scenario.
“The definitions of risk aversion should not be limited to specific probabilities of sea level rise,” Giffen continued. “Rather, risk aversion should be a range of probabilities to allow decision-makers to determine their own definition of risk aversion.”
Giffen added the high-risk aversion scenario should not be implemented as a requirement until more data about its associated probabilities becomes available.
A representative from Heal the Bay stated, “While we agree that protecting public access is an important pillar of the commission … other impacts associated with sea level rise need to be fully considered, including the threat of displacement.”
OPC, in its 2018 report, ultimately stated “the direction of sea level rise is clear” and “scientific understanding of sea level rise is advancing at a rapid pace.”
“The rate of ice loss from the Greenland and Antarctic ice sheets is increasing. New scientific evidences has highlighted the potential for extreme sea level rise,” the OPC 2018 report stated, according to Coastal Commission staff. “Probabilities of specific sea level increases can inform decision. Waiting for scientific certainty is neither a safe or prudent option.”