On Saturday, March 21, 2009, the Seashore and PRNSA hosted Dr. Ann Russell, associate professor of geology at University of California at Davis, to discuss the potential effects of climate change on coastal ecosystems such as the recently restored Giacomini Wetlands. As Dr. Russell noted, changes in the carbon dioxide (CO₂) content in the atmosphere have occurred throughout geologic time, but what is unprecedented is the rate and extent to which CO₂ is increasing: from a geologic standpoint, it is incredibly rapidly and to a magnitude that has not been documented from previous geologic periods.

Dr. Russell recently began a study on the potential hydrologic effects of climate change on Tomales Bay and other northern California coastal systems. In this study, she is evaluating changes in estuarine circulation and water pH relative to conditions present between 1985 and 1996, when Tomales Bay was the subject of an extensive long-term monitoring program, the Land Margin Ecosystems Research (LMER) and Biogeochemical Reactions in Estuaries (BRIE) projects.

Through research efforts such as these, the Seashore and PRNSA hopes to gain a better understanding of how these global changes will affect our local environment and resources and what we can do to better anticipate—and potentially even mitigate—some of these impacts. Below is a synopsis on what is currently known or believed about climate change and its potential impacts on coastal ecosystems.

Top of Page

When planning for project implementation started, few people other than scientists even talked about global warming, climate change, sea level rise, and the impact on wetlands. However, in recent years, the alarming news stories about the potentially rapidly increasing rate of sea level rise due to glacier melting has catapulted this issue into the public eye and increased concern about the resilience of these important and fragile ecosystems. Increases in sea level could reportedly result in loss of more than 22 percent of the world's wetlands (San Francisco Bay Joint Venture 2008). When combined with the continued loss of wetlands globally to reclamation and development, these losses could climb as high as 77 percent (Nicholls et al. 1999, Najjar et al. 2000 in San Francisco Bay Joint Venture 2008).

Climate change can affect coastal wetland systems through a myriad of direct and indirect effects, including changes in temperature, wind, precipitation, freshwater hydrology, sediment supply and transport, sea level rise, and ocean circulation. With climate change study being a relatively young science, the exact magnitude and extent—and even the direction—of these changes on the northern California coast is still a matter of active debate.

Click on a link below to read about:

Sea Level Rise
Precipitation, Run-Off, and Sedimentation
Coastal Winds and Temperature
Coastal Fog
Coastal Upwelling
Acidification of Coastal Waters
Changes in Estuarine Salinity with Sea Level Rise
Nitrogen Deposition
Carbon Sequestration and Interactions of Carbon with Marsh Vegetation Communities
Conclusions
References

-- Content for these pages was composed by Lorraine Parsons, Project Manager, Giacomini Wetland Restoration Project, Point Reyes National Seashore, May 2010

Top of Page