California's Coastal Marshes Face Extinction By 2110

Climate change and coastal development are combining to stamp out important ecological landscapes.

1 minute read

March 2, 2018, 12:00 PM PST

By Elana Eden


San Luis Obispo County

Los Osos, in San Luis Obispo County, California. | joojoob27 / Shutterstock

Ninety percent of California's wetlands have been lost to development, researchers say—and 100 percent of the marshes remaining could disappear by the end of the century if greenhouse gas emissions don't decrease.

The marshes would have a shot at survival if they could migrate inland, but coastal development patterns are boxing them in, a USGS researcher told KPCC. USGS and UCLA co-authored the new study that calculated the threat to California's coastal ecology.

Besides providing important habitats for millennia, marshes "serve key functions related to the health of the planet," KPCC's Jacob Margolis explains. Their decay could result in even more emissions, as well as erosion and water pollution.

They store carbon, which will be released as they begin to die off. They are barriers to storm surges that protect against erosion. They act as catches for debris that make their way down from the hills after wildfires. And they filter polluted water and sediment that flows from our cities towards the ocean, keeping our seas a bit cleaner.

Further explanation, and a picture slideshow, are included in the full story.

Wednesday, February 21, 2018 in KPCC

Young Professional

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban and Environmental Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban and Environmental Planner

Get top-rated, practical training for planners

"Planetizen federal action tracker" logo superimposed over black and white image of US Capitol dome.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

5 hours ago - Zachary Whalen

Overlapping highways

The state-sanctioned urbicide of Austin

People don’t kill cities. Freeways do.

September 8, 2026 - Benjamin Schneider

The Hoover Dam blocking the Colorado River. The river's water level is noticeably low. The cliffs surrounding the blue water are brown and jagged.

US to reduce Colorado River water deliveries to Mexico

A new Colorado Treaty amendment reduces Mexico’s Colorado River water allocation by 250,000 acre feet.

September 11, 2026 - The Arizona Republic

A cluster of wind turbines beneath a stormy sky, above a forest where the leaves are beginning to change colors.

5 New England states march closer to 800 megawatt wind energy project

Securing federal approval for the project may be complicated under the Trump administration, which has historically been hostile towards domestic wind power.

1 hour ago - Inside Climate News

People boarding a bus on Maryland's Orange Route.

Baltimore to break ground on $50 million Transit Priority Project

The project will bring faster bus trips, safer streets and better bike connections to Baltimore.

2 hours ago - Mass Transit

A brick building with a circular sign with the Airbnb logo hanging off of it.

Airbnb launches $250 million 'last-dollar financing' housing accelerator, makes first investment in Austin

The company will put $6.4 million towards affordable housing development in Texas’ capital.

3 hours ago - Smart Cities Dive

FREE Course: Walkable City 1: Why Walkability?

After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.

Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold

The course focuses on the opportunities and imperatives that shape reinvention of mall sites.