Dozens of world-class scientists and economists, many from the University of California and state research institutes, are examining potential effects of warming on snowpacks, wildfires, crops and electricity demand.
Further reports will examine climate effects on hospital admissions, mortality rates, pollution and the habitats of the state's animals and plants. Dutch experts have been consulted on how to armor the coast with improved dikes and sea walls -- controversial measures that some experts contend will only increase erosion.
Detailed studies, now undergoing peer review, are to be released over the next month. Then the Climate Action Team is to send a comprehensive report to Gov. Arnold Schwarzenegger.
Sea levels along California have risen an average of about 8 inches in the past century. According to the Pacific Institute report, 260,000 Californians already live in flood zones, but are assumed to be protected by existing levees and sea walls. A rise of 1.4 meters (55 inches) would increase the population at risk to 480,000. Currently, 1,900 miles of roads and highways are at risk of flooding, which would grow to 3,500 miles under the sea level rise projections.
The report estimated that one adaptation strategy, armoring the coast with 1,100 miles of new or modified sea walls and levees, would cost at least $14 billion to construct, and another $1.4 billion a year to maintain.
The report's estimate of 1 to 1.4 meters of sea level rise by the end of the century was calculated using two scenarios envisioned by the United Nations' Intergovernmental Panel on Climate Change, a gathering of the world's top climate scientists. One scenario assumes countries will cut their emissions of planet-heating greenhouse gases, and another assumes a business-as-usual release level.
Despite more than a decade of warnings from scientists, global emissions continue to rise, fueled by rapid population growth and economic development in such nations as China and India. Unless greenhouse gases are cut significantly, Earth's temperature is expected to increase between 4 and 6 degrees Celsius by the end of the century, according to the U.N. panel.
As water warms due to rising air temperatures, it expands, causing the sea level to rise. But another major factor, the melting of the Greenland and Antarctic ice sheets, was unaccounted for in the U.N. panel's models because of uncertainty over effects and timing. Those models were designed in the mid-1990s.
