Global warming poses one of the world's most serious and potentially devastating environmental threats. But the changing climate doesn't just threaten the world, it threatens our world, right here in the Bay Area. Development has cost us much of our wetlands; climate change could claim more. It could flood our coastline, and make high-tide levels seen only every 100 years in the bay occur 10 times as often. Warmer waters could eliminate cold-water fish from our streams, expanded wildfires could rob us of our signature oaks, and higher temperatures could make the Central Valley's agricultural lands even thirstier for water from the Bay-Delta.
The Bay Area's specific contribution to the problem is difficult to quantify precisely. But gasoline consumption, vehicle use, and household electricity consumption have been increasing in our region. And with electric power plants and motor vehicles the main sources of greenhouse gases, the trends, until recently, were going in the wrong direction. The good news is that the Bay Area joined the rest of California in reducing electricity use significantly in the first half of 2001.
NRDC researchers examined the two chief causes of global-warming pollution in the United States: vehicle use and electricity consumption. According to California Department of Transportation data, vehicle miles traveled in the nine Bay Area counties increased more than 20 percent between 1990 and 2000. In addition, California Energy Commission data for 1992 and 1997 indicate that annual residential electricity use in the Bay Area increased by 9.5 percent, an average of about 1.6 percentage points each year.
Neither increase is accounted for by population growth alone -- electricity consumption increased for each household, and the rate of increase in vehicle miles driven far outpaces population (Bay Area population grew 12.6 percent over the last decade). But population increases have, and will continue to have, a multiplying effect.
There is good news, however: significant reductions in electricity use occurred in the Bay Area between January and June 2001, in response to the state's energy crisis. In June alone, almost 30 percent of households served by PG&E cut their consumption by at least 20 percent, compared with June 2000, and statewide consumption dropped by 8 percent.