The Pacific giant salamander, which can no longer be found in Big Sur due to climate change. | Image public domain, Wikimedia Commons
By Cade Johnson
Have you ever imagined the Central Coast as a desert? If you stick around long enough, you may not have to: Climate change has already started painting a picture of a region where heat-trapping emissions reign, and the ecosystem has no choice but to adapt.
Scientists warn that if we remain on our current trajectory, what is now a dynamic stretch of the Pacific coast with a Mediterranean climate, vibrant tidepools and decades-old oak woodlands is on track to becoming a California desert tortoise sanctuary, where there are more days on average per year of temperatures exceeding 100 degrees than Las Vegas has now.
Desertification is dawning on the Central Coast, according to University of California, Santa Cruz ecology professor Barry Sinervo, and the impact can be seen in the disappearance of a uniquely giant and talkative amphibian from a southern Monterey County site: the Pacific giant salamander.
In 1975, herpetologist Dr. Robert C. Stebbins observed the Pacific giant salamander in the Santa Lucia Mountains of Big Sur, surrounded by cool, damp redwoods along the rugged coast. The salamander, which sometimes grows to over a foot in length, is one of the largest in the world. It has been said to make “croaking or barking sounds” when threatened, according to Scientific American, and it has “blade-like” teeth and a marbled back. The site in Big Sur where it was observed in the 1970s was the southernmost point of the species’ geographical range, which extends northward into British Columbia.
But sometime between 1975 and 2012, according to Sinervo, the salamander disappeared from Big Sur. Now, the southernmost habitat for the salamander is near Redwood Road in Corralitos, some 80 miles north of Big Sur.
Sinervo, who contributed to California’s fourth climate assessment on the Central Coast region, urged in the report that the region is at risk of “desert-ification,” or developing the hot, dry environmental conditions that are characteristic of regions with desert climates. This suggestion may be slightly less surprising in 2020 to Monterey Bay area residents than in previous years, given the community has seen multiple heat waves and wildfires in the past few months alone.
Fog, which the marine layer helps to keep around longer, provides a protective bubble for our coast’s biodiversity, but it is diminishing gradually.
In 50 years, the climate and environmental conditions of the Central Coast may match those of the Mojave Desert, according to the report. This transformation would have a range of implications for the region’s biodiversity. The California desert tortoise, which is native to the Mojave Desert, would by then find the projected hot, arid conditions in the Central Coast to its liking. Some endangered species from the Central Valley, like the blunt-nosed leopard lizard, may thrive under such desert-like climates, but at a high cost to the region’s current biodiversity.
“I think it’s sad,” said Gage Dayton, administrative director of the UC Santa Cruz Natural Reserves. The university’s Landels-Hill Big Creek reserve is near the site where the salamander disappeared, according to Sinervo.
“Many of the organisms are not going to be able to adapt or migrate at the rate (of climate change) that we’re seeing and going to be seeing,” Dayton added.
The Central Coast is a point of overlap for amphibian and reptilian species. It is where many amphibian species reach the southernmost part and reptilian species reach the northernmost part of their respective ranges of geographical distribution. As climate change is expected to drive temperatures up throughout the next century, amphibian species found in the Central Coast may experience local extinctions that push the southernmost point of their range further north, as in the case of the Pacific giant salamander.
Mammals, too, are at risk of becoming climate refugees driven away from their native habitats. Researchers for University of Washington and The Nature Conservancy modeled the future pathways of 2,954 species of animals as they migrate to escape the heating of the southern United States from climate change. The model demonstrated that mammals will move overwhelmingly northward or to areas of higher elevation.
According to the Union of Concerned Scientists’ report on “extreme heat,” or temperatures exceeding 100 degrees, Monterey County — which has had one day of extreme heat per year on average — is expected to have nine days of extreme heat per year by the middle of the century, and 22 days of extreme heat per year by the late 21st century. Santa Cruz County, which has historically had zero days of extreme heat per year on average, is headed toward having nine days of extreme heat per year by the end of the century.
“Certainly if we look at California, or globally, [with] the frequency of extreme heat events on the rise, in the Central Coast region we would also expect there to be more frequent and more extreme heat in the future,” said Kristina Dahl, senior climate scientist at the Union of Concerned Scientists.
The Central Coast has an advantage — for now. The marine layer blankets the land and its organisms with cool air and protects the region from heat. This results in our communities not seeing the impacts of climate change quite as quickly, according to state climatologist Michael Anderson.
But as the Earth gets warmer, the “ability to condense water vapor into clouds and marine layer gets harder,” Anderson said. “We’d have more days without it.”
In a 2010 study, UC Berkeley researchers inferred a 33 percent reduction in summer fog frequency since the early 20th century. Such effects of the reduced fog and warming in the Santa Cruz Mountains have led to the extirpation of the northern alligator lizard, which now only persists in more heavily forested regions of the Central Coast. Fog, which the marine layer helps to keep around longer, provides a protective bubble for our coast’s biodiversity, but it is diminishing gradually.
Dahl and Anderson said that a key part of climate change is that temperatures at night will continue to rise as well. Data published by the National Oceanic and Atmospheric Administration indicates that nighttime temperatures during the summer are warmer now and are rising at a quicker rate than daytime temperatures.
This is important because people and animals rely on cooler temperatures at night to shed the excess heat accumulated in the body. Without the cool nights to alleviate the body during a heat wave, excess heat can be dangerous or, in severe cases, deadly.
One of Dahl’s areas of expertise is the impact of climate change on sea level, which, like temperatures, is expected to rise in the coming decades. The primary threat that sea level rise poses to the Central Coast is erosion, Dahl noted. Erosion caused by sea level rise can make cliffs weaker and may threaten ecosystems, habitats and neighborhoods in ways that Dahl says are “harder to quantify” in terms of calculating risk.
In order to put the Central Coast less at risk of the impacts of climate change, Dahl said that we have to be working on two fronts: adaptation and litigation.
The “adaptation” front requires making changes in our communities that help us cope better, Dahl said, with the climate impacts that are already on the way, like altering policies around vegetation buffers to better protect structures against wildfire or developing heat adaptation plans to address the needs of low-income and vulnerable populations. One example Dahl referenced was New York City’s Cooling Assistance Benefit program implemented in May this year, which helps households cover the cost of an air conditioner or fan.
Litigation may involve introducing legislation to reduce carbon dioxide emissions, but more important than that, Dahl said, would be voting, advocating and holding elected officials accountable for reducing emissions.
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