Global warming is everyone's responsibility Global warming is everyone's responsibility (July 29, 2005)

Bay Area not immune from ravages of climate change

By Stan Van Velsor

There is an overwhelming scientific consensus that heat-trapping gases caused by burning fossil fuels, like oil and coal, have modified the temperature on Earth. The level of carbon dioxide (the primary heat-trapping gas) in our atmosphere has increased by over 30 percent since the beginning of the industrial revolution, with a corresponding 1.1-degree Fahrenheit increase in the average global temperature and a 5-degree average increase at the poles. Unless significant action is taken to reduce carbon dioxide emissions, scientists predict that global warming could raise the average temperature of the planet by as much as 15 degrees Fahrenheit by 2100.

We have an opportunity as well as the responsibility to care for the Earth's unique and life-sustaining ecosystems of forests, oceans, grasslands and human societies. The fate of the Earth is our own fate, and when we pollute the Earth we are destroying our home. Just as homeowners are responsible for keeping their home in good working condition, so are we responsible for maintaining the Earth's life support systems. Just as parents are responsible for helping their children to grow up healthy and happy, so are we responsible for making sure we leave them a healthy world.

The change in climate caused by global warming will have irreversible consequences on all aspects of our lives, including flooded coastal zones, increased frequency and severity of storms, worsening droughts and heat waves, species extinction and geopolitical instability. California will not escape the potential havoc brought on by climate change, nor will those of us living in the Bay Area. There are three areas in particular where climate change will have profound consequences on Bay Area residents: our water resources, human health and coastal habitats.

Rising temperature and the likely decline in winter precipitation will result in a significant reduction in Sierra Nevada snowpack. Eighty percent of California's annual precipitation falls during the winter. The Sierra Nevada snowpack is a critical source of water during the late spring and summer, when 75 percent of California's water use occurs. As snowpack declines and stream flow becomes less reliable, water shortages are likely to become more common. A 2004 study reported in the Proceedings of the National Academy of Sciences predicts that by the end of the century the Sierra Nevada snowpack could be reduced by 30 to 70 percent, which could affect 85 percent of the agricultural and urban water users in the San Francisco Bay Area.

Extreme heat waves and high-temperature events will increase in severity and frequency as the temperature rises. California's increasingly urban population will be at greatest risk for heat-related deaths. The Proceedings study predicts that heat waves will likely double in frequency by 2050 in five major metropolitan areas -- Los Angeles, Riverside/San Bernardino, San Francisco, Sacramento and Fresno.

Sea level rise poses a serious threat to Bay Area coastal resources, which will increase the risk of storm damage, erosion and flooding in the San Francisco Bay and the Sacramento-San Joaquin Delta. Rich farmlands, small communities, highways, diverse wetland ecosystems and valuable real estate are protected by several thousand miles of levees made more vulnerable by rising sea level. Salt water intrusion into freshwater aquifers is also a potential consequence of rising sea level.

In the words of Gov. Schwarzenegger, "I say the debate is over. We know the science. We know the time for action is now." We have the ability right now to eliminate dirty fossil fuels and transform our society to one based on clean energy sources like solar, wind and geothermal energy. Addressing this problem will require commitment from people all over the world, so let the change begin with us. We need to continue what each of us is already doing to protect the Earth, like recycling and using energy-efficient appliances. But we also need to speak up for environmental policies that promote renewable energy, energy-efficient building design, and cleaner automobiles.
Stan Van Velsor is global warming program coordinator for the Loma Prieta Chapter of the Sierra Club.

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