GREEN CITY Changes to ocean and air temperatures, rising sea levels, loss of habitat, scarcity of food, altered precipitation patterns, environmental asynchronicity these are the concerns of wildlife biologists who are watching the increased effects of climate change on the thousands of plant and animal species that share the earth with people. Overall, global warming threatens a third of existing species, with 50 percent now in general decline due to a variety of human activities.
Bay Area wildlife is already being negatively affected by a warmer world, one that locally manifests in nesting birds roasting to death during heat waves, plummeting fish populations, and starving whales. Those stories were part of "Irreplaceable: Wildlife in a warming world," a recent seminar held at the San Francisco Public Library by the Endangered Species Coalition. Maria Brown, superintendent of Gulf of the Farallones National Marine Sanctuary one of the most biologically diverse regions in the world, shared a grim account of the Cassin's auklet.
"This little seabird you maybe never heard of may predict the future of climate change in San Francisco," said Brown.
The auklet spends most of its life far out at sea, and flies inland to breed in burrows on remote islands and coastlines. Invasive grasses have choked many of the prime burrowing spots along the coast, so wildlife biologists have installed bird boxes as an alternative. April, the height of the annual nesting season, was an unusually warm month, with thermometers on the Farallones Islands clocking 90-degree temperatures. The bird boxes turned into ovens. "They literally cooked," said Brown of the breeding auklets. "This is a prediction of what's to come."
The auklet's story also shows how species have already been negatively impacted by human activity, even before dramatic climate change was factored into the equation. That's a point all the speakers drove home.
"We're dealing with these threats that already exist. Now with climate change we superimpose all these unknowns," said Tamara Williams, a hydrologist for the Golden Gate National Recreation Area, a 60-mile swath of incredibly diverse land spanning from Tomales Bay to San Mateo that is home to 34 threatened or endangered species more than any other national park in continental North America. "Those listed species were listed without considering impacts of climate change. We're dealing with species that were in trouble already."
And how will it affect other species that aren't listed? Williams gave an example of the coast redwood, which relies on a foggy environment to stave off drought during summer months. Will the coast continue to be as foggy as it's been in the past? "We wish we could predict what's going to happen, but we can't," she said.
Mike Lynes of Golden Gate Audubon said the Bay Area has global significance for birds, but there's already been a 90 percent loss of its historic wetlands one of the primary habitats for shorebirds, which are already in a 50 percent decline. Climate change is only going to make the world harder for them, he said as he flashed maps of altered land masses in the event of a one-meter sea level rise the modest prediction for what will happen by 2100. The maps showed that such a rise will cause wetlands in Richmond, along the Petaluma River, and in Silicon Valley to disappear.