Newswire: California, Britain to unite on global warming battle, and just in time too

Prime Minister Tony Blair of Britain and Governor Arnold Schwarzenegger of California announced an agreement to bypass the Bush administration and work together to explore ways to fight global warming.

And it's a good thing too...

Study predicts a much hotter, drier California
_Jane Kay, Chronicle Environment Writer_

California will become significantly hotter and drier by the end of the century, causing severe air pollution, a drop in the water supply, melting of 90 percent of the Sierra snowpack and up to six times more heat-related deaths in major urban centers, according to a sweeping study compiled with help from respected scientists from around the country.

The weather -- up to 10.5 degrees warmer by 2100 -- would make last month's heat wave look average. If industrial and vehicle emissions continue unabated, there could be up to 100 more days a year when temperatures hit 90 degrees or above in Los Angeles and 95 degrees or above in Sacramento. Both cities have about 20 days of such extreme heat now.

The good news: If emissions of carbon dioxide and other greenhouse gases are significantly curtailed, according to the report released Tuesday, the number of extremely hot days might only increase by half that amount.

The report, released by the California Environmental Protection Agency, comes from the California Climate Change Center, established three years ago by the California Energy Commission. Scripps Institution of Oceanography and UC Berkeley are responsible for the core research and about 75 scientists from universities, government agencies and nonprofit groups contributed to the report, which has been billed as a layperson's guide to technical documents prepared in support of initiatives to address global warming by Gov. Schwarzenegger and legislators. "What we wanted to do with the document is summarize the scientific reports, so regular citizens can understand the grave concerns that we believe are facing California,'' said Claudia Chandler, assistant executive director of the California Energy Commission. Climate experts have faith in the reliability of global climate models and their ability to forecast what will happen to the planet as the heat-trapping greenhouse gases continue to build in the atmosphere.

However, some scientists have been reluctant to say how global warming may affect specific regions, including areas the size of California. That's because there's debate over whether models are good enough to zoom in on possible local effects of planetary climate change. But Chandler said the state was depending on the core of scientists who prepared the report to use the best models available to help the state prepare for possible problems looming in the not too distant future. "We probably won't know until 10 years from now. But that will be too late. We cannot turn our backs on trying to address this very serious situation.'' Highlights of the report include: -- Hotter weather would increase the risk of death from dehydration, heat stroke, heart attacks, stroke and respiratory distress. Under the most extreme scenario, heat-related deaths could increase four or six times. -- The snowpack, the state's top source of fresh drinking water, could nearly disappear. That would pose a challenge to water agencies that now rely on slowly melting snow to replenish reservoirs. -- Power demand could up as much as 20 percent, but hydropower supplies would drop. -- Heat stresses dairy cows, which could produce up to 20 percent less milk. Fruit and nut trees could produce smaller, inferior quality crops. Wine grape quality could be severely impacted in all but the coolest growing regions. -- Sea levels would rise, possibly inundating the Sacramento-San Joaquin Delta, a source of two-thirds of the state's drinking water.

"We looked at agriculture, one of the state's most important sectors, and the increased potential of wildfires,'' said Chandler. "We looked at public health from the standpoint of deteriorating air quality, and the reduced water from the Sierra Nevada snowpack. We looked at what rising sea levels would mean to the delta's water pumps and levees and to the coastal cities of Los Angeles, San Francisco, Oakland and San Diego.''

The study authors based their assessments on what would happen in California under three different emissions scenarios. The amount of emissions would determine the amount of temperature rise over the century as greenhouse gases trapped excess heat that would otherwise radiate into space. These scenarios -- which contain varying assumptions on economic and population growth, use of new efficient technologies and shifts away from the use of fossil fuels -- have been adopted by the United Nations Intergovernmental Panel on Climate Change, a collaboration of 2,000 scientists from 100 countries.

With continued higher emissions, temperature rises are projected between 8 and 10.5-degrees compared to medium emissions with temperature rises between 5.5 and 8-degrees Fahrenheit. With lower emissions, the temperature is projected to rise between 3 and 5.5 degrees Fahrenheit. Those varying scenarios could significantly impact how global warming affects California, the report said. For example, if temperatures rise as much as 5.5 degrees, there will be 75 to 85 percent more days with weather conducive to production of unhealthful smog in Los Angeles and the San Joaquin Valley than now, it said. The days could be cut if emissions stayed at the lower scenario.

Sea levels have already risen about seven inches along the California coast in the past century. If greenhouse gases continue and temperatures rise into the upper range, the ocean is expected to rise 22 to 35 inches by the end of the century. The mix of increasingly severe winter storms and high tides are expected to cause more frequent and severe flooding, erosion and damage to coastal structures, the report said. The report concludes that California policy alone cannot significantly affect the warming planet. "California alone cannot stabilize the planet. However, the state's actions can drive global progress," the report concludes.

If other states and nation's follow California's example of limiting emissions of greenhouse gases "we would be on track to keep temperatures from rising ... and thus avoid the most severe consequences of global warming."