The costs of climate change

From California beachside communities to remote villages in subarctic Alaska, the impacts of climate change are becoming ever more tangible, as shown by two government studies released this week.

"Sea-level rise is here and we need to start planning for it," said Philip King, associate professor of economics at San Francisco State University, in the Los Angeles Times. King co-authored a study of the economic impacts of sea-level rise on five coastal California communities, from San Francisco's Ocean Beach to Torrey Pines in San Diego, and found big losses looming for cities that don't plan for the deluge. Sea level in California has risen 8 inches in the last 100 years and could climb another 55 inches by 2100 as increasing global temperatures cause seawater to expand and ice sheets to melt.

While swelling tides in California wash away beaches and flood coastal areas over the coming century, billions of dollars in tourism, real estate and infrastructure could also be swept out to sea, the study found. In Ocean Beach, for example, more powerful storm surges and erosion could cost $540 million in lost infrastructure, housing and land. Further south, beach erosion at Zuma Beach and Broad Beach in Malibu could mean the loss of over $500 million in tourism spending, tax revenue and wildlife habitat. This study was unique in its local focus, looking at impacts to individual parcels of property to help local governments plan accordingly. Past studies of comparable sea-level rise along the entire California coast found 480,000 people, 350,000 acres of wetlands and almost $100 billion (in 2000 dollars) of property at risk by 2100.

Planning for sea-level rise now could greatly reduce potential future costs, the study said. The cost of protecting the shoreline by adding sand to beaches runs only in the tens of millions locally and would prevent beach erosion caused by emergency sea walls in some locations. "Managed retreat" -- the process of moving cities inland from encroaching shores -- would reduce costs and preserve beaches for recreation and wildlife habitat but would also face difficult planning and political challenges. As noted in the study, "serious consideration of sea-level rise is essential to all short- and long-term coastal planning in California." Commissioned by the California Department of Boating and Waterways, the study was part of a statewide effort started by Gov. Schwarzenegger to assess the impacts of rising seas.

Two thousand miles north, the local effects of climate change were gathered in story form rather than dollar amounts. While Alaskan coastal villages move inland to escape thawing permafrost and melting ice shelves, inland communities are also experiencing climate impacts. In a paper published in the journal Human Organization, social scientists from the US Geological Survey interviewed indigenous Yup'ik people to understand how climate change is affecting their age-old, subsistence lifestyle on the lower Yukon River.

"Salmonberries are getting fewer, that's due to lack of snow," one resident explained of an important wild food source. "See what's happening is, after the snow melts right away the tundra dries up. And that's one of the reasons for lack of salmonberries, the tundra is drying up and they can't grow when it's dry."

As computer models crunch volumes of data to explain climate change impacts, this study sought to understand on-the-ground effects by "relating indigenous observation as described by elders and hunters ... to those described by scientific literature." Another participant described changing weather over time:

Let’s see, maybe in the 80s, late 70s, 80s there was this gradual change started, and it seemed like the winters were getting a little warmer, less snow, rain in December and January. It seems like there’s hardly any snow, frozen tundra, ice.

In winter, Yup'ik people travel by sled dog and snow machine on frozen rivers to trade with other villages and reach hunting grounds. But thinning ice on the Andreafsky River makes travel difficult and dangerous. An 83-year-old woman who lived at the village of St. Mary's for 50 years explained:

Our river goes out to the Yukon not too far, about a mile or a little more, and at this mouth to the Yukon, it doesn’t freeze, it doesn’t freeze, people keep drowning there. I don’t know how many people now, especially young people. They’ve been falling in that hole, I don’t know how many people now down there…because that place never freezes, we hate, I hate that, other people hate that.

Nathan Rice is an editorial fellow at High Country News.

Photo of Broad Beach, California courtesy Flickr user The City Project. 

Photo of St. Mary's, Alaska, courtesy US Geological Survey.