The state will suffer dire long-term consequences if lawmakers set aside concerns about rising seas to focus solely on COVID-19, the non-partisan Legislative Analyst’s Office warned Monday.
Sea level rise will likely put at least $8 billion in property underwater by 2050, and could affect tens of thousands of jobs and billions in gross domestic product, according to studies cited by the office.
“Because the most severe effects of (sea level rise) likely will manifest decades in the future, taking actions to address them now may seem less pressing compared to the immediate pandemic‑related challenges currently facing the state,” says the new report from the office.
“The magnitude of the potential impacts, however, mean that the state cannot afford to indefinitely delay taking steps to prepare. Waiting too long to initiate adaptation efforts likely will make responding effectively more difficult and costly.”
Beside properties put underwater, at least $6 billion in additional property will be in jeopardy of flooding during king tides and storm surges, according to the report. Sea level rise and related flooding and erosion — consequences of climate change — also pose threats to water treatment plants, roads, marinas, ports and railways.
Evidence of the threat can be seen in ever-rising king tides, which spill onto Pacific Coast Highway in Huntington Beach and pound the boulders protecting beachfront homes in south Orange County. More recently, high tides and big surf flooded streets in Newport Beach’s Balboa Peninsula on July 3. The same swell took out a walkway in Capistrano Beach, which also suffered a boardwalk collapse from high waters in 2018.
Related erosion resulted in a December 2018 bluff collapse in Del Mar, forcing temporary closure of the rail line there. The coastal railroad in San Clemente and Dana Point is also vulnerable.
“The next decade represents a crucial time period for taking action to prepare for (sea level rise),” the report says.
Three basic strategies for adapting to sea-level rise were outlined in a December report by the Legislative Analyst’s Office. However, at least two come with complicating factors.
Protection. While listed by the analyst’s office, the state Coastal Commission generally opposes new coastal armoring, such as seawalls, to protect existing structures, preferring a strategy of “managed retreat” that allows the ocean — and beaches — to migrate inland. Seawalls contribute to the loss of beaches — and with them, public recreation areas — according to the commission. However, the commission is largely supportive of new natural protections afforded by enhancing dunes and wetlands.
Relocation. This is part of what the Coastal Commission refers to as managed retreat, but the state study notes it “can be difficult, costly or impossible to relocate existing development.”
Accommodation. New building should take into account future sea level rise and some existing buildings can be “flood proofed” by being elevated, according to the December report.
While efforts to slow the spread of coronavirus are cutting into public budgets, there’s still plenty that lawmakers can do about sea level rise, according to Monday’s followup report.
“State and local governments can undertake some essential near‑term preparation activities — such as planning, establishing relationships and forums for regional coordination, and sharing information — with relatively minor upfront investments,” the report says.
Property and infrastructure aren’t the only things threatened by rising seas.
While existing dunes and wetlands can absorb flooding before it reaches man-made property, the damage to the habitat can eliminate the homes for birds, fish and plants.
In economic terms, coastal economies could suffer from the loss of beaches, and damage to ports could chip into the $350 billion of goods that arrive in the state by sea, according to the report.
Among the threats to water supplies is the possibility that rising seas would bring about a subterranean intrusion that would contaminate fresh groundwater aquifers.
Global sea levels have risen about 8 inches since 1880 and annual increases have been accelerating in recent decades, according to the National Oceanic and Atmospheric Administration.
“The global mean water level in the ocean rose by 0.14 inches per year from 2006–2015, which was 2.5 times the average rate of 0.06 inches per year throughout most of the twentieth century,” according to the agency.
That annual increase is expected to continue, and to grow more dramatically, well into the future.
The state’s Ocean Protection Council has predicted there’s a 66% chance that sea levels will rise another 3.5 feet statewide by 2100 unless greenhouse gas emissions are radically reduced. However, in its “Strategic Plan to Protect California’s Coast and Ocean 2020-2025,” the council established a goal of preparing for 3.5 feet of sea level rise by 2050 — 50 years sooner.
“This level of safety was deemed necessary because new models regularly predict more sea level rise, not less, and the analysis did not account for king tides or storm events,” said Justine Kimball, senior program manager for the council’s Climate Change Program, in a July email to the the Southern California News Group.
With sea level rise of 3 feet to 6 feet, “up to two-thirds of Southern California beaches may become completely eroded by the year 2100,” says the state report, citing research by the United States Geological Survey.
Source: Orange County Register