Will Climate Change Affect Catalina?

2014-11-26
Catalina Island Conservancy

The Catalina Island Conservancy and other land managers all over the globe must now address climate as they plan for the future. The U.S. Environmental Protection Agency reports that the Earth's average temperature has increased by 1.4 degrees F over the last century, and that it's expected to increase by another 2 to 11.5 degrees over the next hundred years.

Rising global temperatures, accompanied by a warmer, more acidic ocean, have caused changes in weather and climate worldwide. Predicted changes include more extremes—prolonged drought, more frequent and intense heat waves, more frequent and intense storms (including hurricanes and cyclones), rising sea level (due to melting glaciers and the fact that warmer ocean water takes up more space), and bigger flood events.

Most scientists agree that the current episode of climate change has largely been caused by human activities. The burning of fossil fuels has increased greenhouse gases in Earth’s atmosphere. Greenhouse gases trap heat and maintain a habitable planet. But too high a concentration of these gases in our atmosphere and too much heat can lead to a set of conditions that stress natural and human systems.

Catalina Island may be somewhat buffered from the temperature effects of climate change. As a result of being surrounded by ocean, Catalina experiences less severe seasonal temperature extremes. It’s typically cooler in the summer and warmer in the winter than comparable mainland Mediterranean-type ecosystems.

On the moisture side, frequent fog on the Island reduces water stress for Island plants, and that regime may continue. On the other hand, having evolved for millennia with this fog, Island plants may also be less tolerant of extended periods of drought and, therefore, more sensitive to climate change. Aaron Ramirez, a researcher at University of California, Berkeley, is currently conducting a study to determine how climate change may impact the Island’s flora by comparing island and mainland varieties of the same plant families.

Rising sea level caused by climate change may alter Catalina’s coastline, but not much, given steep terrain. According to a July 2014 paper in Bioscience, an increase of 5 meters (which is likely over the next couple hundred years) will result in a loss of 1.4% of total land area. Other Channel Islands will see greater effects—increased coastal erosion, reduced habitat for cliff nesting birds, altered organization of marine ecosystems, and destruction of coastal archeological sites.

By Alexa Johnson
Alexa Johnson is the Catalina Island Conservancy’s Outreach and Naturalist Training Specialist. For more information, please visit our website.