Foon Rhee

Should California worry about Antarctic melting?

A new study says that loss of the ice sheet, such as the Thwaites Glacier in West Antarctica, could dramatically accelerate sea level rise on California’s coast.
A new study says that loss of the ice sheet, such as the Thwaites Glacier in West Antarctica, could dramatically accelerate sea level rise on California’s coast. NASA

If you’ve seen the breathtaking images of the massive cracking ice shelf in Antarctica, you probably have more appreciation for the potential impact along California’s coast.

Scientists warn that a 2,000-square-mile chunk (bigger than Merced County) could soon break away. A new study commissioned by the state highlights the rapid loss of the Antarctic ice sheet as one of the biggest wild cards that could significantly accelerate sea level rise – to as much as 10 feet by the year 2100. That would be 30 to 40 times faster than over the last century and could devastate coastal counties where three-fourths of Californians live.

It’s all about the latest science, which you might have noticed is under siege these days. Just ask the thousands who marched on Earth Day across America.

The report will be presented Wednesday to the state Ocean Protection Council, which plans public workshops in May and June before adopting updated policies in January.

Melting ice in Greenland and the Antarctic from global warming will soon become the primary cause of rising sea levels, the study says, overtaking warming oceans and melting mountain glaciers. While glaciers contain enough ice to raise average global sea levels by 1.5 feet, the Greenland ice sheet has enough for 24 feet and the Antarctic 187 feet. For every foot of sea-level rise caused by ice loss in West Antarctica, the Pacific Ocean will rise about 1.25 feet along California, according to the study.

In 2012, the prestigious National Research Council projected that sea levels along most of California’s coast could rise by as much as 1 foot in 20 years, 2 feet by 2050 and 5.5 feet by the end of the century. At higher risk are low-lying areas of the San Francisco Bay and Southern California that are home to airports, freeways and stadiums built only a few feet above the high-tide line. Inland areas, including Stockton and other cities in the Delta, are also in danger because they are less than 4 feet above sea level. In all, more than 374,000 people and 160,000 homes in California are at risk.

There is some hope.

Sea level rise can be reduced with aggressive efforts on global warming, the new study says. With those efforts, the San Francisco Bay Area is likely to have sea level rise between 1 and 2.4 feet by 2100. Without successful efforts, the range increases to 1.6 to 3.4 feet.

While restricting or moving coastal development is highly contentious, California is taking steps. A 2015 state law requires cities and counties to consider sea level rise in planning efforts, while a 2015 executive order by Gov. Jerry Brown directs state agencies to prepare for sea level rise.

Allowing new development right on the ocean is courting disaster, so these steps will help. But I’d feel a lot better if we had a president who takes climate change seriously.

By the numbers

The average projected sea level rise, in feet above the 1991-2009 average, at selected locations:





Crescent City





San Francisco





La Jolla





* With successful efforts on climate change; **Without successful efforts on climate change

Source: California Ocean Protection Council